2877 lines
108 KiB
PHP

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This defines the core classes of the Moodle question engine.
*
* @package moodlecore
* @subpackage questionengine
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
require_once(dirname(__FILE__) . '/states.php');
require_once(dirname(__FILE__) . '/datalib.php');
require_once(dirname(__FILE__) . '/renderer.php');
require_once(dirname(__FILE__) . '/bank.php');
require_once(dirname(__FILE__) . '/../type/questiontype.php');
require_once(dirname(__FILE__) . '/../type/questionbase.php');
require_once(dirname(__FILE__) . '/../type/rendererbase.php');
require_once(dirname(__FILE__) . '/../behaviour/behaviourbase.php');
require_once(dirname(__FILE__) . '/../behaviour/rendererbase.php');
require_once($CFG->libdir . '/questionlib.php');
/**
* This static class provides access to the other question engine classes.
*
* It provides functions for managing question behaviours), and for
* creating, loading, saving and deleting {@link question_usage_by_activity}s,
* which is the main class that is used by other code that wants to use questions.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class question_engine {
/** @var array behaviour name => 1. Records which behaviours have been loaded. */
private static $loadedbehaviours = array();
/**
* Create a new {@link question_usage_by_activity}. The usage is
* created in memory. If you want it to persist, you will need to call
* {@link save_questions_usage_by_activity()}.
*
* @param string $component the plugin creating this attempt. For example mod_quiz.
* @param object $context the context this usage belongs to.
* @return question_usage_by_activity the newly created object.
*/
public static function make_questions_usage_by_activity($component, $context) {
return new question_usage_by_activity($component, $context);
}
/**
* Load a {@link question_usage_by_activity} from the database, based on its id.
* @param integer $qubaid the id of the usage to load.
* @return question_usage_by_activity loaded from the database.
*/
public static function load_questions_usage_by_activity($qubaid) {
$dm = new question_engine_data_mapper();
return $dm->load_questions_usage_by_activity($qubaid);
}
/**
* Save a {@link question_usage_by_activity} to the database. This works either
* if the usage was newly created by {@link make_questions_usage_by_activity()}
* or loaded from the database using {@link load_questions_usage_by_activity()}
* @param question_usage_by_activity the usage to save.
*/
public static function save_questions_usage_by_activity(question_usage_by_activity $quba) {
$dm = new question_engine_data_mapper();
$observer = $quba->get_observer();
if ($observer instanceof question_engine_unit_of_work) {
$observer->save($dm);
} else {
$dm->insert_questions_usage_by_activity($quba);
}
}
/**
* Delete a {@link question_usage_by_activity} from the database, based on its id.
* @param integer $qubaid the id of the usage to delete.
*/
public static function delete_questions_usage_by_activity($qubaid) {
global $CFG;
self::delete_questions_usage_by_activities($CFG->prefix . 'question_usages.id = ' . $qubaid);
}
/**
* Delete a {@link question_usage_by_activity} from the database, based on its id.
* @param integer $qubaid the id of the usage to delete.
*/
public static function delete_questions_usage_by_activities($where) {
$dm = new question_engine_data_mapper();
$dm->delete_questions_usage_by_activities($where);
}
/**
* Change the maxmark for the question_attempt with number in usage $slot
* for all the specified question_attempts.
* @param qubaid_condition $qubaids Selects which usages are updated.
* @param integer $slot the number is usage to affect.
* @param number $newmaxmark the new max mark to set.
*/
public static function set_max_mark_in_attempts(qubaid_condition $qubaids,
$slot, $newmaxmark) {
$dm = new question_engine_data_mapper();
$dm->set_max_mark_in_attempts($qubaids, $slot, $newmaxmark);
}
/**
* @param array $questionids of question ids.
* @return boolean whether any of these questions are being used by the question engine.
*/
public static function questions_in_use(array $questionids) {
$dm = new question_engine_data_mapper();
return $dm->questions_in_use($questionids);
}
/**
* Create an archetypal behaviour for a particular question attempt.
* Used by {@link question_definition::make_behaviour()}.
*
* @param string $preferredbehaviour the type of model required.
* @param question_attempt $qa the question attempt the model will process.
* @return question_behaviour an instance of appropriate behaviour class.
*/
public static function make_archetypal_behaviour($preferredbehaviour, question_attempt $qa) {
question_engine::load_behaviour_class($preferredbehaviour);
$class = 'qbehaviour_' . $preferredbehaviour;
if (!constant($class . '::IS_ARCHETYPAL')) {
throw new Exception('The requested behaviour is not actually an archetypal one.');
}
return new $class($qa, $preferredbehaviour);
}
/**
* @param string $behaviour the name of a behaviour.
* @return array of {@link question_display_options} field names, that are
* not relevant to this behaviour before a 'finish' action.
*/
public static function get_behaviour_unused_display_options($behaviour) {
self::load_behaviour_class($behaviour);
$class = 'qbehaviour_' . $behaviour;
if (!method_exists($class, 'get_unused_display_options')) {
return question_behaviour::get_unused_display_options();
}
return call_user_func(array($class, 'get_unused_display_options'));
}
/**
* Create an behaviour for a particular type. If that type cannot be
* found, return an instance of qbehaviour_missing.
*
* Normally you should use {@link make_archetypal_behaviour()}, or
* call the constructor of a particular model class directly. This method
* is only intended for use by {@link question_attempt::load_from_records()}.
*
* @param string $behaviour the type of model to create.
* @param question_attempt $qa the question attempt the model will process.
* @param string $preferredbehaviour the preferred behaviour for the containing usage.
* @return question_behaviour an instance of appropriate behaviour class.
*/
public static function make_behaviour($behaviour, question_attempt $qa, $preferredbehaviour) {
try {
self::load_behaviour_class($behaviour);
} catch (Exception $e) {
question_engine::load_behaviour_class('missing');
return new qbehaviour_missing($qa, $preferredbehaviour);
}
$class = 'qbehaviour_' . $behaviour;
return new $class($qa, $preferredbehaviour);
}
/**
* Load the behaviour class(es) belonging to a particular model. That is,
* include_once('/question/behaviour/' . $behaviour . '/behaviour.php'), with a bit
* of checking.
* @param string $qtypename the question type name. For example 'multichoice' or 'shortanswer'.
*/
public static function load_behaviour_class($behaviour) {
global $CFG;
if (isset(self::$loadedbehaviours[$behaviour])) {
return;
}
$file = $CFG->dirroot . '/question/behaviour/' . $behaviour . '/behaviour.php';
if (!is_readable($file)) {
throw new Exception('Unknown question behaviour ' . $behaviour);
}
include_once($file);
self::$loadedbehaviours[$behaviour] = 1;
}
/**
* Return an array where the keys are the internal names of the archetypal
* behaviours, and the values are a human-readable name. An
* archetypal behaviour is one that is suitable to pass the name of to
* {@link question_usage_by_activity::set_preferred_behaviour()}.
*
* @return array model name => lang string for this behaviour name.
*/
public static function get_archetypal_behaviours() {
$archetypes = array();
$behaviours = get_list_of_plugins('question/behaviour');
foreach ($behaviours as $path) {
$behaviour = basename($path);
self::load_behaviour_class($behaviour);
$plugin = 'qbehaviour_' . $behaviour;
if (constant($plugin . '::IS_ARCHETYPAL')) {
$archetypes[$behaviour] = self::get_behaviour_name($behaviour);
}
}
asort($archetypes, SORT_LOCALE_STRING);
return $archetypes;
}
/**
* Return an array where the keys are the internal names of the behaviours
* in preferred order and the values are a human-readable name.
*
* @param array $archetypes, array of behaviours
* @param string $questionbehavioursorder, a comma separated list of behaviour names
* @param string $questionbehavioursdisabled, a comma separated list of behaviour names
* @param string $currentbahaviour, current behaviour name
* @return array model name => lang string for this behaviour name.
*/
public static function sort_behaviours($archetypes, $questionbehavioursorder,
$questionbehavioursdisabled, $currentbahaviour) {
$behaviourorder = array();
$behaviourdisabled = array();
// Get disabled behaviours
if ($questionbehavioursdisabled) {
$behaviourdisabledtemp = preg_split('/[\s,;]+/', $questionbehavioursdisabled);
} else {
$behaviourdisabledtemp = array();
}
if ($questionbehavioursorder) {
$behaviourordertemp = preg_split('/[\s,;]+/', $questionbehavioursorder);
} else {
$behaviourordertemp = array();
}
foreach ($behaviourdisabledtemp as $key) {
if (array_key_exists($key, $archetypes)) {
// Do not disable the current behaviour
if ($key != $currentbahaviour) {
$behaviourdisabled[$key] = $archetypes[$key];
}
}
}
// Get behaviours in preferred order
foreach ($behaviourordertemp as $key) {
if (array_key_exists($key, $archetypes)) {
$behaviourorder[$key] = $archetypes[$key];
}
}
// Get the rest of behaviours and sort them alphabetically
$leftover = array_diff_key($archetypes, $behaviourdisabled, $behaviourorder);
asort($leftover, SORT_LOCALE_STRING);
// Set up the final order to be displayed
$finalorder = $behaviourorder + $leftover;
return $finalorder;
}
/**
* Return an array where the keys are the internal names of the behaviours
* in preferred order and the values are a human-readable name.
*
* @param string $currentbahaviour
* @return array model name => lang string for this behaviour name.
*/
public static function get_behaviour_options($currentbahaviour) {
global $CFG;
$archetypes = self::get_archetypal_behaviours();
// If no admin setting return all behavious
if (!$CFG->questionbehavioursdisabled && !$CFG->questionbehavioursorder) {
return $archetypes;
}
return self::sort_behaviours($archetypes, $CFG->questionbehavioursorder,
$CFG->questionbehavioursdisabled, $currentbahaviour);
}
/**
* Get the translated name of an behaviour, for display in the UI.
* @param string $behaviour the internal name of the model.
* @return string name from the current language pack.
*/
public static function get_behaviour_name($behaviour) {
return get_string($behaviour, 'qbehaviour_' . $behaviour);
}
/**
* Returns the valid choices for the number of decimal places for showing
* question marks. For use in the user interface.
* @return array suitable for passing to {@link choose_from_menu()} or similar.
*/
public static function get_dp_options() {
return question_display_options::get_dp_options();
}
public static function initialise_js() {
return question_flags::initialise_js();
}
}
/**
* This class contains all the options that controls how a question is displayed.
*
* Normally, what will happen is that the calling code will set up some display
* options to indicate what sort of question display it wants, and then before the
* question is rendered, the behaviour will be given a chance to modify the
* display options, so that, for example, A question that is finished will only
* be shown read-only, and a question that has not been submitted will not have
* any sort of feedback displayed.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_display_options {
/**#@+ @var integer named constants for the values that most of the options take. */
const HIDDEN = 0;
const VISIBLE = 1;
const EDITABLE = 2;
/**#@-*/
/**#@+ @var integer named constants for the {@link $marks} option. */
const MAX_ONLY = 1;
const MARK_AND_MAX = 2;
/**#@-*/
/**
* @var integer maximum value for the {@link $markpd} option. This is
* effectively set by the database structure, which uses NUMBER(12,7) columns
* for question marks/fractions.
*/
const MAX_DP = 7;
/**
* @var boolean whether the question should be displayed as a read-only review,
* or in an active state where you can change the answer.
*/
public $readonly = false;
/**
* @var boolean whether the question type should output hidden form fields
* to reset any incorrect parts of the resonse to blank.
*/
public $clearwrong = false;
/**
* Should the student have what they got right and wrong clearly indicated.
* This includes the green/red hilighting of the bits of their response,
* whether the one-line summary of the current state of the question says
* correct/incorrect or just answered.
* @var integer {@link question_display_options::HIDDEN} or
* {@link question_display_options::VISIBLE}
*/
public $correctness = self::VISIBLE;
/**
* The the mark and/or the maximum available mark for this question be visible?
* @var integer {@link question_display_options::HIDDEN},
* {@link question_display_options::MAX_ONLY} or {@link question_display_options::MARK_AND_MAX}
*/
public $marks = self::MARK_AND_MAX;
/** @var number of decimal places to use when formatting marks for output. */
public $markdp = 2;
/**
* Should the flag this question UI element be visible, and if so, should the
* flag state be changable?
* @var integer {@link question_display_options::HIDDEN},
* {@link question_display_options::VISIBLE} or {@link question_display_options::EDITABLE}
*/
public $flags = self::VISIBLE;
/**
* Should the specific feedback be visible.
* @var integer {@link question_display_options::HIDDEN} or
* {@link question_display_options::VISIBLE}
*/
public $feedback = self::VISIBLE;
/**
* For questions with a number of sub-parts (like matching, or
* multiple-choice, multiple-reponse) display the number of sub-parts that
* were correct.
* @var integer {@link question_display_options::HIDDEN} or
* {@link question_display_options::VISIBLE}
*/
public $numpartscorrect = self::VISIBLE;
/**
* Should the general feedback be visible?
* @var integer {@link question_display_options::HIDDEN} or
* {@link question_display_options::VISIBLE}
*/
public $generalfeedback = self::VISIBLE;
/**
* Should the automatically generated display of what the correct answer is
* be visible?
* @var integer {@link question_display_options::HIDDEN} or
* {@link question_display_options::VISIBLE}
*/
public $rightanswer = self::VISIBLE;
/**
* Should the manually added marker's comment be visible. Should the link for
* adding/editing the comment be there.
* @var integer {@link question_display_options::HIDDEN},
* {@link question_display_options::VISIBLE}, or {@link question_display_options::EDITABLE}.
* Editable means that form fields are displayed inline.
*/
public $manualcomment = self::VISIBLE;
/**
* Should we show a 'Make comment or override grade' link?
* @var string base URL for the edit comment script, which will be shown if
* $manualcomment = self::VISIBLE.
*/
public $manualcommentlink = null;
/**
* Used in places like the question history table, to show a link to review
* this question in a certain state. If blank, a link is not shown.
* @var string base URL for a review question script.
*/
public $questionreviewlink = null;
/**
* Should the history of previous question states table be visible?
* @var integer {@link question_display_options::HIDDEN} or
* {@link question_display_options::VISIBLE}
*/
public $history = self::HIDDEN;
/**
* Set all the feedback-related fields {@link $feedback}, {@link generalfeedback},
* {@link rightanswer} and {@link manualcomment} to
* {@link question_display_options::HIDDEN}.
*/
public function hide_all_feedback() {
$this->feedback = self::HIDDEN;
$this->numpartscorrect = self::HIDDEN;
$this->generalfeedback = self::HIDDEN;
$this->rightanswer = self::HIDDEN;
$this->manualcomment = self::HIDDEN;
$this->correctness = self::HIDDEN;
}
/**
* Returns the valid choices for the number of decimal places for showing
* question marks. For use in the user interface.
*
* Calling code should probably use {@link question_engine::get_dp_options()}
* rather than calling this method directly.
*
* @return array suitable for passing to {@link choose_from_menu()} or similar.
*/
public static function get_dp_options() {
$options = array();
for ($i = 0; $i <= self::MAX_DP; $i += 1) {
$options[$i] = $i;
}
return $options;
}
}
/**
* Contains the logic for handling question flags.
*
* @copyright 2010 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class question_flags {
/**
* Get the checksum that validates that a toggle request is valid.
* @param integer $qubaid the question usage id.
* @param integer $questionid the question id.
* @param integer $sessionid the question_attempt id.
* @param object $user the user. If null, defaults to $USER.
* @return string that needs to be sent to question/toggleflag.php for it to work.
*/
protected static function get_toggle_checksum($qubaid, $questionid, $qaid, $user = null) {
if (is_null($user)) {
global $USER;
$user = $USER;
}
return md5($qubaid . "_" . $user->secret . "_" . $questionid . "_" . $qaid);
}
/**
* Get the postdata that needs to be sent to question/toggleflag.php to change the flag state.
* You need to append &newstate=0/1 to this.
* @return the post data to send.
*/
public static function get_postdata(question_attempt $qa) {
$qaid = $qa->get_database_id();
$qubaid = $qa->get_usage_id();
$qid = $qa->get_question()->id;
$checksum = self::get_toggle_checksum($qubaid, $qid, $qaid);
return "qaid=$qaid&qubaid=$qubaid&qid=$qid&checksum=$checksum&sesskey=" . sesskey();
}
/**
* If the request seems valid, update the flag state of a question attempt.
* Throws exceptions if this is not a valid update request.
* @param integer $qubaid the question usage id.
* @param integer $questionid the question id.
* @param integer $sessionid the question_attempt id.
* @param string $checksum checksum, as computed by {@link get_toggle_checksum()}
* corresponding to the last three arguments.
* @param boolean $newstate the new state of the flag. true = flagged.
*/
public static function update_flag($qubaid, $questionid, $qaid, $checksum, $newstate) {
// Check the checksum - it is very hard to know who a question session belongs
// to, so we require that checksum parameter is matches an md5 hash of the
// three ids and the users username. Since we are only updating a flag, that
// probably makes it sufficiently difficult for malicious users to toggle
// other users flags.
if ($checksum != question_flags::get_toggle_checksum($qubaid, $questionid, $qaid)) {
throw new Exception('checksum failure');
}
$dm = new question_engine_data_mapper();
$dm->update_question_attempt_flag($qubaid, $questionid, $qaid, $newstate);
}
public static function initialise_js() {
global $CFG;
require_js(array('yui_yahoo','yui_dom','yui_event','yui_connection'));
require_js($CFG->wwwroot . '/question/qengine.js');
$config = array(
'actionurl' => $CFG->wwwroot . '/question/toggleflag.php',
'flagicon' => $CFG->pixpath . '/i/flagged.png',
'unflagicon' => $CFG->pixpath . '/i/unflagged.png',
'flagtooltip' => get_string('clicktoflag', 'question'),
'unflagtooltip' => get_string('clicktounflag', 'question'),
'flaggedalt' => get_string('flagged', 'question'),
'unflaggedalt' => get_string('notflagged', 'question'),
);
return print_js_config($config, 'qengine_config', true);
}
}
class question_out_of_sequence_exception extends moodle_exception {
function __construct($qubaid, $slot, $postdata) {
if ($postdata == null) {
$postdata = data_submitted();
}
parent::__construct('submissionoutofsequence', 'question', '', null,
"QUBAid: $qubaid, slot: $slot, post data: " . print_r($postdata, true));
}
}
/**
* This class keeps track of a group of questions that are being attempted,
* and which state, and so on, each one is currently in.
*
* A quiz attempt or a lesson attempt could use an instance of this class to
* keep track of all the questions in the attempt and process student submissions.
* It is basically a collection of {@question_attempt} objects.
*
* The questions being attempted as part of this usage are identified by an integer
* that is passed into many of the methods as $slot. ($question->id is not
* used so that the same question can be used more than once in an attempt.)
*
* Normally, calling code should be able to do everything it needs to be calling
* methods of this class. You should not normally need to get individual
* {@question_attempt} objects and play around with their inner workind, in code
* that it outside the quetsion engine.
*
* Instances of this class correspond to rows in the question_usages table.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_usage_by_activity {
/**
* @var integer|string the id for this usage. If this usage was loaded from
* the database, then this is the database id. Otherwise a unique random
* string is used.
*/
protected $id = null;
/**
* @var string name of an archetypal behaviour, that should be used
* by questions in this usage if possible.
*/
protected $preferredbehaviour = null;
/** @var object the context this usage belongs to. */
protected $context;
/** @var string plugin name of the plugin this usage belongs to. */
protected $owningcomponent;
/** @var array {@link question_attempt}s that make up this usage. */
protected $questionattempts = array();
/** @var question_usage_observer that tracks changes to this usage. */
protected $observer;
/**
* Create a new instance. Normally, calling code should use
* {@link question_engine::make_questions_usage_by_activity()} or
* {@link question_engine::load_questions_usage_by_activity()} rather than
* calling this constructor directly.
*
* @param string $component the plugin creating this attempt. For example mod_quiz.
* @param object $context the context this usage belongs to.
*/
public function __construct($component, $context) {
$this->owningcomponent = $component;
$this->context = $context;
$this->observer = new question_usage_null_observer();
}
/**
* @param string $behaviour the name of an archetypal behaviour, that should
* be used by questions in this usage if possible.
*/
public function set_preferred_behaviour($behaviour) {
$this->preferredbehaviour = $behaviour;
$this->observer->notify_modified();
}
/** @return string the name of the preferred behaviour. */
public function get_preferred_behaviour() {
return $this->preferredbehaviour;
}
/** @return stdClass the context this usage belongs to. */
public function get_owning_context() {
return $this->context;
}
/** @return string the name of the plugin that owns this attempt. */
public function get_owning_component() {
return $this->owningcomponent;
}
/** @return integer|string If this usage came from the database, then the id
* from the question_usages table is returned. Otherwise a random string is
* returned. */
public function get_id() {
if (is_null($this->id)) {
$this->id = random_string(10);
}
return $this->id;
}
/** @return question_usage_observer that is tracking changes made to this usage. */
public function get_observer() {
return $this->observer;
}
/**
* For internal use only. Used by {@link question_engine_data_mapper} to set
* the id when a usage is saved to the database.
* @param integer $id the newly determined id for this usage.
*/
public function set_id_from_database($id) {
$this->id = $id;
foreach ($this->questionattempts as $qa) {
$qa->set_usage_id($id);
}
}
/**
* Add another question to this usage.
*
* The added question is not started until you call {@link start_question()}
* on it.
*
* @param question_definition $question the question to add.
* @param number $maxmark the maximum this question will be marked out of in
* this attempt (optional). If not given, $question->defaultmark is used.
* @return integer the number used to identify this question within this usage.
*/
public function add_question(question_definition $question, $maxmark = null) {
$qa = new question_attempt($question, $this->get_id(), $this->observer, $maxmark);
if (count($this->questionattempts) == 0) {
$this->questionattempts[1] = $qa;
} else {
$this->questionattempts[] = $qa;
}
$qa->set_number_in_usage(end(array_keys($this->questionattempts)));
$this->observer->notify_attempt_added($qa);
return $qa->get_slot();
}
/**
* Get the question_definition for a question in this attempt.
* @param integer $slot the number used to identify this question within this usage.
* @return question_definition the requested question object.
*/
public function get_question($slot) {
return $this->get_question_attempt($slot)->get_question();
}
/** @return array all the identifying numbers of all the questions in this usage. */
public function get_question_numbers() {
return array_keys($this->questionattempts);
}
/** @return integer the identifying number of the first question that was added to this usage. */
public function get_first_question_number() {
reset($this->questionattempts);
return key($this->questionattempts);
}
/** @return integer the number of questions that are currently in this usage. */
public function question_count() {
return count($this->questionattempts);
}
/**
* Note the part of the {@link question_usage_by_activity} comment that explains
* that {@link question_attempt} objects should be considered part of the inner
* workings of the question engine, and should not, if possible, be accessed directly.
*
* @return question_attempt_iterator for iterating over all the questions being
* attempted. as part of this usage.
*/
public function get_attempt_iterator() {
return new question_attempt_iterator($this);
}
/**
* Check whether $number actually corresponds to a question attempt that is
* part of this usage. Throws an exception if not.
*
* @param integer $slot a number allegedly identifying a question within this usage.
*/
protected function check_slot($slot) {
if (!array_key_exists($slot, $this->questionattempts)) {
throw new exception("There is no question_attempt number $slot in this attempt.");
}
}
/**
* Note the part of the {@link question_usage_by_activity} comment that explains
* that {@link question_attempt} objects should be considered part of the inner
* workings of the question engine, and should not, if possible, be accessed directly.
*
* @param integer $slot the number used to identify this question within this usage.
* @return question_attempt the corresponding {@link question_attempt} object.
*/
public function get_question_attempt($slot) {
$this->check_slot($slot);
return $this->questionattempts[$slot];
}
/**
* Get the current state of the attempt at a question.
* @param integer $slot the number used to identify this question within this usage.
* @return question_state.
*/
public function get_question_state($slot) {
return $this->get_question_attempt($slot)->get_state();
}
/**
* @param integer $slot the number used to identify this question within this usage.
* @param boolean $showcorrectness Whether right/partial/wrong states should
* be distinguised.
* @return string A brief textual description of the current state.
*/
public function get_question_state_string($slot, $showcorrectness) {
return $this->get_question_attempt($slot)->get_state_string($showcorrectness);
}
/**
* Get the time of the most recent action performed on a question.
* @param integer $slot the number used to identify this question within this usage.
* @return integer timestamp.
*/
public function get_question_action_time($slot) {
return $this->get_question_attempt($slot)->get_last_action_time();
}
/**
* Get the current fraction awarded for the attempt at a question.
* @param integer $slot the number used to identify this question within this usage.
* @return number|null The current fraction for this question, or null if one has
* not been assigned yet.
*/
public function get_question_fraction($slot) {
return $this->get_question_attempt($slot)->get_fraction();
}
/**
* Get the current mark awarded for the attempt at a question.
* @param integer $slot the number used to identify this question within this usage.
* @return number|null The current mark for this question, or null if one has
* not been assigned yet.
*/
public function get_question_mark($slot) {
return $this->get_question_attempt($slot)->get_mark();
}
/**
* Get the maximum mark possible for the attempt at a question.
* @param integer $slot the number used to identify this question within this usage.
* @return number the available marks for this question.
*/
public function get_question_max_mark($slot) {
return $this->get_question_attempt($slot)->get_max_mark();
}
/**
* Get the current mark awarded for the attempt at a question.
* @param integer $slot the number used to identify this question within this usage.
* @return number|null The current mark for this question, or null if one has
* not been assigned yet.
*/
public function get_total_mark() {
$mark = 0;
foreach ($this->questionattempts as $qa) {
if ($qa->get_state() == question_state::$needsgrading) {
return null;
}
$mark += $qa->get_mark();
}
return $mark;
}
/**
* @return string a simple textual summary of the question that was asked.
*/
public function get_question_summary($slot) {
return $this->get_question_attempt($slot)->get_question_summary();
}
/**
* @return string a simple textual summary of response given.
*/
public function get_response_summary($slot) {
return $this->get_question_attempt($slot)->get_response_summary();
}
/**
* @return string a simple textual summary of the correct resonse.
*/
public function get_right_answer_summary($slot) {
return $this->get_question_attempt($slot)->get_right_answer_summary();
}
/**
* Get the {@link core_question_renderer}, in collaboration with appropriate
* {@link qbehaviour_renderer} and {@link qtype_renderer} subclasses, to generate the
* HTML to display this question.
* @param integer $slot the number used to identify this question within this usage.
* @param question_display_options $options controls how the question is rendered.
* @param string|null $number The question number to display. 'i' is a special
* value that gets displayed as Information. Null means no number is displayed.
* @return string HTML fragment representing the question.
*/
public function render_question($slot, $options, $number = null) {
return $this->get_question_attempt($slot)->render($options, $number);
}
/**
* Generate any bits of HTML that needs to go in the <head> tag when this question
* is displayed in the body.
* @param integer $slot the number used to identify this question within this usage.
* @return string HTML fragment.
*/
public function render_question_head_html($slot) {
return $this->get_question_attempt($slot)->render_head_html();
}
/**
* Like {@link render_question()} but displays the question at the past step
* indicated by $seq, rather than showing the latest step.
*
* @param integer $slot the number used to identify this question within this usage.
* @param integer $seq the seq number of the past state to display.
* @param question_display_options $options controls how the question is rendered.
* @param string|null $number The question number to display. 'i' is a special
* value that gets displayed as Information. Null means no number is displayed.
* @return string HTML fragment representing the question.
*/
public function render_question_at_step($slot, $seq, $options, $number = null) {
return $this->get_question_attempt($slot)->render_at_step($seq, $options, $number, $this->preferredbehaviour);
}
/**
* Replace a particular question_attempt with a different one.
*
* For internal use only. Used when reloading the state of a question from the
* database.
*
* @param array $records Raw records loaded from the database.
* @param integer $questionattemptid The id of the question_attempt to extract.
* @return question_attempt The newly constructed question_attempt_step.
*/
public function replace_loaded_question_attempt_info($slot, $qa) {
$this->check_slot($slot);
$this->questionattempts[$slot] = $qa;
}
/**
* You should probably not use this method in code outside the question engine.
* The main reason for exposing it was for the benefit of unit tests.
* @param integer $slot the number used to identify this question within this usage.
* @return string return the prefix that is pre-pended to field names in the HTML
* that is output.
*/
public function get_field_prefix($slot) {
return $this->get_question_attempt($slot)->get_field_prefix();
}
/**
* Start the attempt at a question that has been added to this usage.
* @param integer $slot the number used to identify this question within this usage.
*/
public function start_question($slot) {
$qa = $this->get_question_attempt($slot);
$qa->start($this->preferredbehaviour);
$this->observer->notify_attempt_modified($qa);
}
/**
* Start the attempt at all questions that has been added to this usage.
*/
public function start_all_questions() {
foreach ($this->questionattempts as $qa) {
$qa->start($this->preferredbehaviour);
$this->observer->notify_attempt_modified($qa);
}
}
/**
* Start the attempt at a question, starting from the point where the previous
* question_attempt $oldqa had reached. This is used by the quiz 'Each attempt
* builds on last' mode.
* @param integer $slot the number used to identify this question within this usage.
* @param question_attempt $oldqa a previous attempt at this quetsion that
* defines the starting point.
*/
public function start_question_based_on($slot, question_attempt $oldqa) {
$qa = $this->get_question_attempt($slot);
$qa->start_based_on($oldqa);
$this->observer->notify_attempt_modified($qa);
}
/**
* Process all the question actions in the current request.
*
* If there is a parameter slots included in the post data, then only
* those question numbers will be processed, otherwise all questions in this
* useage will be.
*
* This function also does {@link update_question_flags()}.
*
* @param integer $timestamp optional, use this timestamp as 'now'.
* @param array $postdata optional, only intended for testing. Use this data
* instead of the data from $_POST.
*/
public function process_all_actions($timestamp = null, $postdata = null) {
$slots = question_attempt::get_submitted_var('slots', PARAM_SEQUENCE, $postdata);
if (is_null($slots)) {
$slots = $this->get_question_numbers();
} else if (!$slots) {
$slots = array();
} else {
$slots = explode(',', $slots);
}
foreach ($slots as $slot) {
$this->validate_sequence_number($slot, $postdata);
$submitteddata = $this->extract_responses($slot, $postdata);
$this->process_action($slot, $submitteddata, $timestamp);
}
$this->update_question_flags($postdata);
}
/**
* Get the submitted data from the current request that belongs to this
* particular question.
*
* @param integer $slot the number used to identify this question within this usage.
* @param $postdata optional, only intended for testing. Use this data
* instead of the data from $_POST.
* @return array submitted data specific to this question.
*/
public function extract_responses($slot, $postdata = null) {
return $this->get_question_attempt($slot)->get_submitted_data($postdata);
}
/**
* Process a specific action on a specific question.
* @param integer $slot the number used to identify this question within this usage.
* @param $submitteddata the submitted data that constitutes the action.
*/
public function process_action($slot, $submitteddata, $timestamp = null) {
$qa = $this->get_question_attempt($slot);
$qa->process_action($submitteddata, $timestamp);
$this->observer->notify_attempt_modified($qa);
}
/**
* Check that the sequence number, that detects weird things like the student
* clicking back, is OK.
* @param integer $slot the number used to identify this question within this usage.
* @param array $submitteddata the submitted data that constitutes the action.
*/
public function validate_sequence_number($slot, $postdata = null) {
$qa = $this->get_question_attempt($slot);
$sequencecheck = question_attempt::get_submitted_var(
$qa->get_control_field_name('sequencecheck'), PARAM_INT, $postdata);
if (!is_null($sequencecheck) && $sequencecheck != $qa->get_num_steps()) {
throw new question_out_of_sequence_exception($this->id, $slot, $postdata);
}
}
/**
* Update the flagged state for all question_attempts in this usage, if their
* flagged state was changed in the request.
*
* @param $postdata optional, only intended for testing. Use this data
* instead of the data from $_POST.
*/
public function update_question_flags($postdata = null) {
foreach ($this->questionattempts as $qa) {
$flagged = question_attempt::get_submitted_var(
$qa->get_flag_field_name(), PARAM_BOOL, $postdata);
if (!is_null($flagged) && $flagged != $qa->is_flagged()) {
$qa->set_flagged($flagged);
}
}
}
/**
* Get the correct response to a particular question. Passing the results of
* this method to {@link process_action()} will probably result in full marks.
* @param integer $slot the number used to identify this question within this usage.
* @return array that constitutes a correct response to this question.
*/
public function get_correct_response($slot) {
return $this->get_question_attempt($slot)->get_correct_response();
}
/**
* Finish the active phase of an attempt at a question.
*
* This is an external act of finishing the attempt. Think, for example, of
* the 'Submit all and finish' button in the quiz. Some behaviours,
* (for example, immediatefeedback) give a way of finishing the active phase
* of a question attempt as part of a {@link process_action()} call.
*
* After the active phase is over, the only changes possible are things like
* manual grading, or changing the flag state.
*
* @param integer $slot the number used to identify this question within this usage.
*/
public function finish_question($slot, $timestamp = null) {
$qa = $this->get_question_attempt($slot);
$qa->finish($timestamp);
$this->observer->notify_attempt_modified($qa);
}
/**
* Finish the active phase of an attempt at a question. See {@link finish_question()}
* for a fuller description of what 'finish' means.
*/
public function finish_all_questions($timestamp = null) {
foreach ($this->questionattempts as $qa) {
$qa->finish($timestamp);
$this->observer->notify_attempt_modified($qa);
}
}
/**
* Perform a manual grading action on a question attempt.
* @param integer $slot the number used to identify this question within this usage.
* @param string $comment the comment being added to the question attempt.
* @param number $mark the mark that is being assigned. Can be null to just
* add a comment.
*/
public function manual_grade($slot, $comment, $mark) {
$qa = $this->get_question_attempt($slot);
$qa->manual_grade($comment, $mark);
$this->observer->notify_attempt_modified($qa);
}
/**
* Regrade a question in this usage. This replays the sequence of submitted
* actions to recompute the outcomes.
* @param integer $slot the number used to identify this question within this usage.
* @param boolean $finished whether the question attempt should be forced to be finished
* after the regrade, or whether it may still be in progress (default false).
* @param number $newmaxmark (optional) if given, will change the max mark while regrading.
*/
public function regrade_question($slot, $finished = false, $newmaxmark = null) {
$oldqa = $this->get_question_attempt($slot);
if (is_null($newmaxmark)) {
$newmaxmark = $oldqa->get_max_mark();
}
$this->observer->notify_delete_attempt_steps($oldqa);
$newqa = new question_attempt($oldqa->get_question(), $oldqa->get_usage_id(),
$this->observer, $newmaxmark);
$newqa->set_database_id($oldqa->get_database_id());
$newqa->regrade($oldqa, $finished);
$this->questionattempts[$slot] = $newqa;
$this->observer->notify_attempt_modified($newqa);
}
/**
* Regrade all the questions in this usage (without changing their max mark).
* @param boolean $finished whether each question should be forced to be finished
* after the regrade, or whether it may still be in progress (default false).
*/
public function regrade_all_questions($finished = false) {
foreach ($this->questionattempts as $slot => $notused) {
$this->regrade_question($slot, $finished);
}
}
/**
* Create a question_usage_by_activity from records loaded from the database.
*
* For internal use only.
*
* @param array $records Raw records loaded from the database.
* @param integer $questionattemptid The id of the question_attempt to extract.
* @return question_attempt The newly constructed question_attempt_step.
*/
public static function load_from_records(&$records, $qubaid) {
$record = current($records);
while ($record->qubaid != $qubaid) {
$record = next($records);
if (!$record) {
throw new Exception("Question usage $qubaid not found in the database.");
}
}
$quba = new question_usage_by_activity($record->component,
get_context_instance_by_id($record->contextid));
$quba->set_id_from_database($record->qubaid);
$quba->set_preferred_behaviour($record->preferredbehaviour);
$quba->observer = new question_engine_unit_of_work($quba);
while ($record && $record->qubaid == $qubaid && !is_null($record->slot)) {
$quba->questionattempts[$record->slot] =
question_attempt::load_from_records($records,
$record->questionattemptid, $quba->observer,
$quba->get_preferred_behaviour());
$record = current($records);
}
return $quba;
}
}
/**
* A class abstracting access to the
* {@link question_usage_by_activity::$questionattempts} array.
*
* This class snapshots the list of {@link question_attempts} to iterate over
* when it is created. If a question is added to the usage mid-iteration, it
* will now show up.
*
* To create an instance of this class, use
* {@link question_usage_by_activity::get_attempt_iterator()}
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_iterator implements Iterator, ArrayAccess {
/** @var question_usage_by_activity that we are iterating over. */
protected $quba;
/** @var array of question numbers. */
protected $slots;
/**
* To create an instance of this class, use {@link question_usage_by_activity::get_attempt_iterator()}.
* @param $quba the usage to iterate over.
*/
public function __construct(question_usage_by_activity $quba) {
$this->quba = $quba;
$this->slots = $quba->get_question_numbers();
$this->rewind();
}
/** @return question_attempt_step */
public function current() {
return $this->offsetGet(current($this->slots));
}
/** @return integer */
public function key() {
return current($this->slots);
}
public function next() {
next($this->slots);
}
public function rewind() {
reset($this->slots);
}
/** @return boolean */
public function valid() {
return current($this->slots) !== false;
}
/** @return boolean */
public function offsetExists($slot) {
return in_array($slot, $this->slots);
}
/** @return question_attempt_step */
public function offsetGet($slot) {
return $this->quba->get_question_attempt($slot);
}
public function offsetSet($slot, $value) {
throw new Exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot set.');
}
public function offsetUnset($slot) {
throw new Exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot unset.');
}
}
/**
* Tracks an attempt at one particular question in a {@link question_usage_by_activity}.
*
* Most calling code should need to access objects of this class. They should be
* able to do everything through the usage interface. This class is an internal
* implementation detail of the question engine.
*
* Instances of this class correspond to rows in the question_attempts table, and
* a collection of {@link question_attempt_steps}. Question inteaction models and
* question types do work with question_attempt objects.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt {
/**
* @var string this is a magic value that question types can return from
* {@link question_definition::get_expected_data()}.
*/
const USE_RAW_DATA = 'use raw data';
/**
* @var string special value used by manual grading because {@link PARAM_NUMBER}
* converts '' to 0.
*/
const PARAM_MARK = 'parammark';
/** @var integer if this attempts is stored in the question_attempts table, the id of that row. */
protected $id = null;
/** @var integer|string the id of the question_usage_by_activity we belong to. */
protected $usageid;
/** @var integer the number used to identify this question_attempt within the usage. */
protected $slot = null;
/**
* @var question_behaviour the behaviour controlling this attempt.
* null until {@link start()} is called.
*/
protected $behaviour = null;
/** @var question_definition the question this is an attempt at. */
protected $question;
/** @var number the maximum mark that can be scored at this question. */
protected $maxmark;
/**
* @var number the minimum fraction that can be scored at this question, so
* the minimum mark is $this->minfraction * $this->maxmark.
*/
protected $minfraction = null;
/**
* @var string plain text summary of the variant of the question the
* student saw. Intended for reporting purposes.
*/
protected $questionsummary = null;
/**
* @var string plain text summary of the response the student gave.
* Intended for reporting purposes.
*/
protected $responsesummary = null;
/**
* @var string plain text summary of the correct response to this question
* variant the student saw. The format should be similar to responsesummary.
* Intended for reporting purposes.
*/
protected $rightanswer = null;
/** @var array of {@link question_attempt_step}s. The steps in this attempt. */
protected $steps = array();
/** @var boolean whether the user has flagged this attempt within the usage. */
protected $flagged = false;
/** @var question_usage_observer tracks changes to the useage this attempt is part of.*/
protected $observer;
/**#@+
* Constants used by the intereaction models to indicate whether the current
* pending step should be kept or discarded.
*/
const KEEP = true;
const DISCARD = false;
/**#@-*/
/**
* Create a new {@link question_attempt}. Normally you should create question_attempts
* indirectly, by calling {@link question_usage_by_activity::add_question()}.
*
* @param question_definition $question the question this is an attempt at.
* @param integer|string $usageid The id of the
* {@link question_usage_by_activity} we belong to. Used by {@link get_field_prefix()}.
* @param question_usage_observer $observer tracks changes to the useage this
* attempt is part of. (Optional, a {@link question_usage_null_observer} is
* used if one is not passed.
* @param number $maxmark the maximum grade for this question_attempt. If not
* passed, $question->defaultmark is used.
*/
public function __construct(question_definition $question, $usageid,
question_usage_observer $observer = null, $maxmark = null) {
$this->question = $question;
$this->usageid = $usageid;
if (is_null($observer)) {
$observer = new question_usage_null_observer();
}
$this->observer = $observer;
if (!is_null($maxmark)) {
$this->maxmark = $maxmark;
} else {
$this->maxmark = $question->defaultmark;
}
}
/** @return question_definition the question this is an attempt at. */
public function get_question() {
return $this->question;
}
/**
* Set the number used to identify this question_attempt within the usage.
* For internal use only.
* @param integer $slot
*/
public function set_number_in_usage($slot) {
$this->slot = $slot;
}
/** @return integer the number used to identify this question_attempt within the usage. */
public function get_slot() {
return $this->slot;
}
/**
* @return integer the id of row for this question_attempt, if it is stored in the
* database. null if not.
*/
public function get_database_id() {
return $this->id;
}
/**
* For internal use only. Set the id of the corresponding database row.
* @param integer $id the id of row for this question_attempt, if it is
* stored in the database.
*/
public function set_database_id($id) {
$this->id = $id;
}
/** @return integer|string the id of the {@link question_usage_by_activity} we belong to. */
public function get_usage_id() {
return $this->usageid;
}
/**
* Set the id of the {@link question_usage_by_activity} we belong to.
* For internal use only.
* @param integer|string the new id.
*/
public function set_usage_id($usageid) {
$this->usageid = $usageid;
}
/** @return string the name of the behaviour that is controlling this attempt. */
public function get_behaviour_name() {
return $this->behaviour->get_name();
}
/**
* For internal use only.
* @return question_behaviour the behaviour that is controlling this attempt.
*/
public function get_behaviour() {
return $this->behaviour;
}
/**
* Set the flagged state of this question.
* @param boolean $flagged the new state.
*/
public function set_flagged($flagged) {
$this->flagged = $flagged;
$this->observer->notify_attempt_modified($this);
}
/** @return boolean whether this question is currently flagged. */
public function is_flagged() {
return $this->flagged;
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for the field that indicates whether this question is flagged.
*
* @return string The field name to use.
*/
public function get_flag_field_name() {
return $this->get_control_field_name('flagged');
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for a question_type variable belonging to this question_attempt.
*
* See the comment on {@link question_attempt_step} for an explanation of
* question type and behaviour variables.
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_qt_field_name($varname) {
return $this->get_field_prefix() . $varname;
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for a question_type variable belonging to this question_attempt.
*
* See the comment on {@link question_attempt_step} for an explanation of
* question type and behaviour variables.
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_behaviour_field_name($varname) {
return $this->get_field_prefix() . '-' . $varname;
}
/**
* Get the name (in the sense a HTML name="" attribute, or a $_POST variable
* name) to use for a control variables belonging to this question_attempt.
*
* Examples are :sequencecheck and :flagged
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_control_field_name($varname) {
return $this->get_field_prefix() . ':' . $varname;
}
/**
* Get the prefix added to variable names to give field names for this
* question attempt.
*
* You should not use this method directly. This is an implementation detail
* anyway, but if you must access it, use {@link question_usage_by_activity::get_field_prefix()}.
*
* @param $varname The short form of the variable name.
* @return string The field name to use.
*/
public function get_field_prefix() {
return 'q' . $this->usageid . ':' . $this->slot . '_';
}
/**
* Get one of the steps in this attempt.
* For internal/test code use only.
* @param integer $i the step number.
* @return question_attempt_step
*/
public function get_step($i) {
if ($i < 0 || $i >= count($this->steps)) {
throw new Exception('Index out of bounds in question_attempt::get_step.');
}
return $this->steps[$i];
}
/**
* Get the number of steps in this attempt.
* For internal/test code use only.
* @return integer the number of steps we currently have.
*/
public function get_num_steps() {
return count($this->steps);
}
/**
* Return the latest step in this question_attempt.
* For internal/test code use only.
* @return question_attempt_step
*/
public function get_last_step() {
if (count($this->steps) == 0) {
return new question_null_step();
}
return end($this->steps);
}
/**
* @return question_attempt_step_iterator for iterating over the steps in
* this attempt, in order.
*/
public function get_step_iterator() {
return new question_attempt_step_iterator($this);
}
/**
* The same as {@link get_step_iterator()}. However, for a
* {@link question_attempt_with_restricted_history} this returns the full
* list of steps, while {@link get_step_iterator()} returns only the
* limited history.
* @return question_attempt_step_iterator for iterating over the steps in
* this attempt, in order.
*/
public function get_full_step_iterator() {
return $this->get_step_iterator();
}
/**
* @return question_attempt_reverse_step_iterator for iterating over the steps in
* this attempt, in reverse order.
*/
public function get_reverse_step_iterator() {
return new question_attempt_reverse_step_iterator($this);
}
/**
* Get the qt data from the latest step that has any qt data. Return $default
* array if it is no step has qt data.
*
* @param string $name the name of the variable to get.
* @param mixed default the value to return no step has qt data.
* (Optional, defaults to an empty array.)
* @return array|mixed the data, or $default if there is not any.
*/
public function get_last_qt_data($default = array()) {
foreach ($this->get_reverse_step_iterator() as $step) {
$response = $step->get_qt_data();
if (!empty($response)) {
return $response;
}
}
return $default;
}
/**
* Get the latest value of a particular question type variable. That is, get
* the value from the latest step that has it set. Return null if it is not
* set in any step.
*
* @param string $name the name of the variable to get.
* @param mixed default the value to return in the variable has never been set.
* (Optional, defaults to null.)
* @return mixed string value, or $default if it has never been set.
*/
public function get_last_qt_var($name, $default = null) {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_qt_var($name)) {
return $step->get_qt_var($name);
}
}
return $default;
}
/**
* Get the latest value of a particular behaviour variable. That is,
* get the value from the latest step that has it set. Return null if it is
* not set in any step.
*
* @param string $name the name of the variable to get.
* @param mixed default the value to return in the variable has never been set.
* (Optional, defaults to null.)
* @return mixed string value, or $default if it has never been set.
*/
public function get_last_behaviour_var($name, $default = null) {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_behaviour_var($name)) {
return $step->get_behaviour_var($name);
}
}
return $default;
}
/**
* Get the current state of this question attempt. That is, the state of the
* latest step.
* @return question_state
*/
public function get_state() {
return $this->get_last_step()->get_state();
}
/**
* @param boolean $showcorrectness Whether right/partial/wrong states should
* be distinguised.
* @return string A brief textual description of the current state.
*/
public function get_state_string($showcorrectness) {
return $this->behaviour->get_state_string($showcorrectness);
}
/**
* @return integer the timestamp of the most recent step in this question attempt.
*/
public function get_last_action_time() {
return $this->get_last_step()->get_timecreated();
}
/**
* Get the current fraction of this question attempt. That is, the fraction
* of the latest step, or null if this question has not yet been graded.
* @return number the current fraction.
*/
public function get_fraction() {
return $this->get_last_step()->get_fraction();
}
/** @return boolean whether this question attempt has a non-zero maximum mark. */
public function has_marks() {
// Since grades are stored in the database as NUMBER(12,7).
return $this->maxmark >= 0.00000005;
}
/**
* @return number the current mark for this question.
* {@link get_fraction()} * {@link get_max_mark()}.
*/
public function get_mark() {
return $this->fraction_to_mark($this->get_fraction());
}
/**
* This is used by the manual grading code, particularly in association with
* validation. If there is a mark submitted in the request, then use that,
* otherwise use the latest mark for this question.
* @return number the current mark for this question.
* {@link get_fraction()} * {@link get_max_mark()}.
*/
public function get_current_manual_mark() {
$mark = self::get_submitted_var($this->get_behaviour_field_name('mark'), question_attempt::PARAM_MARK);
if (is_null($mark)) {
return $this->get_mark();
} else {
return $mark;
}
}
/**
* @param number|null $fraction a fraction.
* @return number|null the corresponding mark.
*/
public function fraction_to_mark($fraction) {
if (is_null($fraction)) {
return null;
}
return $fraction * $this->maxmark;
}
/** @return number the maximum mark possible for this question attempt. */
public function get_max_mark() {
return $this->maxmark;
}
/** @return number the maximum mark possible for this question attempt. */
public function get_min_fraction() {
if (is_null($this->minfraction)) {
throw new Exception('This question_attempt has not been started yet, the min fraction is not yet konwn.');
}
return $this->minfraction;
}
/**
* The current mark, formatted to the stated number of decimal places. Uses
* {@link format_float()} to format floats according to the current locale.
* @param integer $dp number of decimal places.
* @return string formatted mark.
*/
public function format_mark($dp) {
return $this->format_fraction_as_mark($this->get_fraction(), $dp);
}
/**
* The current mark, formatted to the stated number of decimal places. Uses
* {@link format_float()} to format floats according to the current locale.
* @param integer $dp number of decimal places.
* @return string formatted mark.
*/
public function format_fraction_as_mark($fraction, $dp) {
return format_float($this->fraction_to_mark($fraction), $dp);
}
/**
* The maximum mark for this question attempt, formatted to the stated number
* of decimal places. Uses {@link format_float()} to format floats according
* to the current locale.
* @param integer $dp number of decimal places.
* @return string formatted maximum mark.
*/
public function format_max_mark($dp) {
return format_float($this->maxmark, $dp);
}
/**
* Return the hint that applies to the question in its current state, or null.
* @return question_hint|null
*/
public function get_applicable_hint() {
return $this->behaviour->get_applicable_hint();
}
/**
* Produce a plain-text summary of what the user did during a step.
* @param question_attempt_step $step the step in quetsion.
* @return string a summary of what was done during that step.
*/
public function summarise_action(question_attempt_step $step) {
return $this->behaviour->summarise_action($step);
}
/**
* Get the {@link core_question_renderer}, in collaboration with appropriate
* {@link qbehaviour_renderer} and {@link qtype_renderer} subclasses, to generate the
* HTML to display this question attempt in its current state.
* @param question_display_options $options controls how the question is rendered.
* @param string|null $number The question number to display.
* @return string HTML fragment representing the question.
*/
public function render($options, $number) {
$qoutput = renderer_factory::get_renderer('core', 'question');
$qtoutput = $this->question->get_renderer();
return $this->behaviour->render($options, $number, $qoutput, $qtoutput);
}
/**
* Generate any bits of HTML that needs to go in the <head> tag when this question
* attempt is displayed in the body.
* @return string HTML fragment.
*/
public function render_head_html() {
return $this->question->get_renderer()->head_code($this) .
$this->behaviour->get_renderer()->head_code($this);
}
/**
* Like {@link render_question()} but displays the question at the past step
* indicated by $seq, rather than showing the latest step.
*
* @param integer $seq the seq number of the past state to display.
* @param question_display_options $options controls how the question is rendered.
* @param string|null $number The question number to display. 'i' is a special
* value that gets displayed as Information. Null means no number is displayed.
* @return string HTML fragment representing the question.
*/
public function render_at_step($seq, $options, $number, $preferredbehaviour) {
$restrictedqa = new question_attempt_with_restricted_history($this, $seq, $preferredbehaviour);
return $restrictedqa->render($options, $number);
}
/**
* Add a step to this question attempt.
* @param question_attempt_step $step the new step.
*/
protected function add_step(question_attempt_step $step) {
$this->steps[] = $step;
end($this->steps);
$this->observer->notify_step_added($step, $this, key($this->steps));
}
/**
* Start (or re-start) this question attempt.
*
* You should not call this method directly. Call
* {@link question_usage_by_activity::start_question()} instead.
*
* @param string|question_behaviour $preferredbehaviour the name of the
* desired archetypal behaviour, or an actual model instance.
* @param $submitteddata optional, used when re-starting to keep the same initial state.
* @param $timestamp optional, the timstamp to record for this action. Defaults to now.
* @param $userid optional, the user to attribute this action to. Defaults to the current user.
*/
public function start($preferredbehaviour, $submitteddata = array(), $timestamp = null, $userid = null) {
// Initialise the behaviour.
if (is_string($preferredbehaviour)) {
$this->behaviour =
$this->question->make_behaviour($this, $preferredbehaviour);
} else {
$class = get_class($preferredbehaviour);
$this->behaviour = new $class($this, $preferredbehaviour);
}
// Record the minimum fraction.
$this->minfraction = $this->behaviour->get_min_fraction();
// Initialise the first step.
$firststep = new question_attempt_step($submitteddata, $timestamp, $userid);
$firststep->set_state(question_state::$todo);
$this->behaviour->init_first_step($firststep);
$this->add_step($firststep);
// Record questionline and correct answer.
// TODO we should only really do this for new attempts, not when called
// via load_from_records.
$this->questionsummary = $this->behaviour->get_question_summary();
$this->rightanswer = $this->behaviour->get_right_answer_summary();
}
/**
* Start this question attempt, starting from the point that the previous
* attempt $oldqa had reached.
*
* You should not call this method directly. Call
* {@link question_usage_by_activity::start_question_based_on()} instead.
*
* @param question_attempt $oldqa a previous attempt at this quetsion that
* defines the starting point.
*/
public function start_based_on(question_attempt $oldqa) {
$this->start($oldqa->behaviour, $oldqa->get_resume_data());
}
/**
* Used by {@link start_based_on()} to get the data needed to start a new
* attempt from the point this attempt has go to.
* @return array name => value pairs.
*/
protected function get_resume_data() {
return $this->behaviour->get_resume_data();
}
/**
* Get a particular parameter from the current request. A wrapper round
* {@link optional_param()}, except that the results is returned without
* slashes.
* @param string $name the paramter name.
* @param integer $type one of the PARAM_... constants.
* @param array $postdata (optional, only inteded for testing use) take the
* data from this array, instead of from $_POST.
* @return mixed the requested value.
*/
public static function get_submitted_var($name, $type, $postdata = null) {
// Special case to work around PARAM_NUMBER converting '' to 0.
if ($type == self::PARAM_MARK) {
$mark = self::get_submitted_var($name, PARAM_RAW_TRIMMED, $postdata);
if ($mark === '') {
return $mark;
} else {
return self::get_submitted_var($name, PARAM_NUMBER, $postdata);
}
}
if (is_null($postdata)) {
$var = optional_param($name, null, $type);
} else if (array_key_exists($name, $postdata)) {
$var = clean_param($postdata[$name], $type);
} else {
$var = null;
}
if (is_string($var)) {
$var = stripslashes($var);
}
return $var;
}
/**
* Get any data from the request that matches the list of expected params.
* @param array $expected variable name => PARAM_... constant.
* @param string $extraprefix '-' or ''.
* @return array name => value.
*/
protected function get_expected_data($expected, $postdata, $extraprefix) {
$submitteddata = array();
foreach ($expected as $name => $type) {
$value = self::get_submitted_var(
$this->get_field_prefix() . $extraprefix . $name, $type, $postdata);
if (!is_null($value)) {
$submitteddata[$extraprefix . $name] = $value;
}
}
return $submitteddata;
}
/**
* Get all the submitted question type data for this question, whithout checking
* that it is valid or cleaning it in any way.
* @return array name => value.
*/
protected function get_all_submitted_qt_vars($postdata) {
if (is_null($postdata)) {
$postdata = $_POST;
}
$pattern = '/^' . preg_quote($this->get_field_prefix()) . '[^-:]/';
$prefixlen = strlen($this->get_field_prefix());
$submitteddata = array();
foreach ($_POST as $name => $value) {
if (preg_match($pattern, $name)) {
$submitteddata[substr($name, $prefixlen)] = $value;
}
}
return $submitteddata;
}
/**
* Get all the sumbitted data belonging to this question attempt from the
* current request.
* @param array $postdata (optional, only inteded for testing use) take the
* data from this array, instead of from $_POST.
* @return array name => value pairs that could be passed to {@link process_action()}.
*/
public function get_submitted_data($postdata = null) {
$submitteddata = $this->get_expected_data(
$this->behaviour->get_expected_data(), $postdata, '-');
$expected = $this->behaviour->get_expected_qt_data();
if ($expected === self::USE_RAW_DATA) {
$submitteddata += $this->get_all_submitted_qt_vars($postdata);
} else {
$submitteddata += $this->get_expected_data($expected, $postdata, '');
}
return $submitteddata;
}
/**
* Get a set of response data for this question attempt that would get the
* best possible mark.
* @return array name => value pairs that could be passed to {@link process_action()}.
*/
public function get_correct_response() {
$response = $this->question->get_correct_response();
$imvars = $this->behaviour->get_correct_response();
foreach ($imvars as $name => $value) {
$response['-' . $name] = $value;
}
return $response;
}
/**
* Change the quetsion summary. Note, that this is almost never necessary.
* This method was only added to work around a limitation of the Opaque
* protocol, which only sends questionLine at the end of an attempt.
* @param $questionsummary the new summary to set.
*/
public function set_question_summary($questionsummary) {
$this->questionsummary = $questionsummary;
$this->observer->notify_attempt_modified($this);
}
/**
* @return string a simple textual summary of the question that was asked.
*/
public function get_question_summary() {
return $this->questionsummary;
}
/**
* @return string a simple textual summary of response given.
*/
public function get_response_summary() {
return $this->responsesummary;
}
/**
* @return string a simple textual summary of the correct resonse.
*/
public function get_right_answer_summary() {
return $this->rightanswer;
}
/**
* Perform the action described by $submitteddata.
* @param array $submitteddata the submitted data the determines the action.
* @param integer $timestamp the time to record for the action. (If not given, use now.)
* @param integer $userid the user to attribute the aciton to. (If not given, use the current user.)
*/
public function process_action($submitteddata, $timestamp = null, $userid = null) {
$pendingstep = new question_attempt_pending_step($submitteddata, $timestamp, $userid);
if ($this->behaviour->process_action($pendingstep) == self::KEEP) {
$this->add_step($pendingstep);
if ($pendingstep->response_summary_changed()) {
$this->responsesummary = $pendingstep->get_new_response_summary();
}
}
}
/**
* Perform a finish action on this question attempt. This corresponds to an
* external finish action, for example the user pressing Submit all and finish
* in the quiz, rather than using one of the controls that is part of the
* question.
*
* @param integer $timestamp the time to record for the action. (If not given, use now.)
* @param integer $userid the user to attribute the aciton to. (If not given, use the current user.)
*/
public function finish($timestamp = null, $userid = null) {
$this->process_action(array('-finish' => 1), $timestamp, $userid);
}
/**
* Perform a regrade. This replays all the actions from $oldqa into this
* attempt.
* @param question_attempt $oldqa the attempt to regrade.
* @param boolean $finished whether the question attempt should be forced to be finished
* after the regrade, or whether it may still be in progress (default false).
*/
public function regrade(question_attempt $oldqa, $finished) {
$first = true;
foreach ($oldqa->get_step_iterator() as $step) {
if ($first) {
$first = false;
$this->start($oldqa->behaviour, $step->get_all_data(),
$step->get_timecreated(), $step->get_user_id());
} else {
$this->process_action($step->get_submitted_data(),
$step->get_timecreated(), $step->get_user_id());
}
}
if ($finished) {
$this->finish();
}
}
/**
* Perform a manual grading action on this attempt.
* @param $comment the comment being added.
* @param $mark the new mark. (Optional, if not given, then only a comment is added.)
* @param integer $timestamp the time to record for the action. (If not given, use now.)
* @param integer $userid the user to attribute the aciton to. (If not given, use the current user.)
* @return unknown_type
*/
public function manual_grade($comment, $mark, $timestamp = null, $userid = null) {
$submitteddata = array('-comment' => $comment);
if (!is_null($mark)) {
$submitteddata['-mark'] = $mark;
$submitteddata['-maxmark'] = $this->maxmark;
}
$this->process_action($submitteddata, $timestamp, $userid);
}
/** @return boolean Whether this question attempt has had a manual comment added. */
public function has_manual_comment() {
foreach ($this->steps as $step) {
if ($step->has_behaviour_var('comment')) {
return true;
}
}
return false;
}
/**
* @return string the most recent manual comment that was added to this question.
* null, if none.
*/
public function get_manual_comment() {
foreach ($this->get_reverse_step_iterator() as $step) {
if ($step->has_behaviour_var('comment')) {
return $step->get_behaviour_var('comment');
}
}
return null;
}
/**
* @return array subpartid => object with fields
* ->responseclassid the
* ->response the actual response the student gave to this part, as a string.
* ->fraction the credit awarded for this subpart, may be null.
* returns an empty array if no analysis is possible.
*/
public function classify_response() {
return $this->behaviour->classify_response();
}
/**
* Create a question_attempt_step from records loaded from the database.
*
* For internal use only.
*
* @param array $records Raw records loaded from the database.
* @param integer $questionattemptid The id of the question_attempt to extract.
* @return question_attempt The newly constructed question_attempt_step.
*/
public static function load_from_records(&$records, $questionattemptid,
question_usage_observer $observer, $preferredbehaviour) {
$record = current($records);
while ($record->questionattemptid != $questionattemptid) {
$record = next($records);
if (!$record) {
throw new Exception("Question attempt $questionattemptid not found in the database.");
}
}
try {
$question = question_bank::load_question($record->questionid);
} catch (Exception $e) {
// The question must have been deleted somehow. Create a missing
// question to use in its place.
$question = question_bank::get_qtype('missingtype')->make_deleted_instance(
$record->questionid, $record->maxmark + 0);
}
$qa = new question_attempt($question, $record->questionusageid, null, $record->maxmark + 0);
$qa->set_database_id($record->questionattemptid);
$qa->set_number_in_usage($record->slot);
$qa->minfraction = $record->minfraction + 0;
$qa->set_flagged($record->flagged);
$qa->questionsummary = $record->questionsummary;
$qa->rightanswer = $record->rightanswer;
$qa->responsesummary = $record->responsesummary;
$qa->timemodified = $record->timemodified;
$qa->behaviour = question_engine::make_behaviour(
$record->behaviour, $qa, $preferredbehaviour);
$i = 0;
while ($record && $record->questionattemptid == $questionattemptid && !is_null($record->attemptstepid)) {
$qa->steps[$i] = question_attempt_step::load_from_records($records, $record->attemptstepid);
if ($i == 0) {
$question->init_first_step($qa->steps[0]);
}
$i++;
$record = current($records);
}
$qa->observer = $observer;
return $qa;
}
}
/**
* This subclass of question_attempt pretends that only part of the step history
* exists. It is used for rendering the question in past states.
*
* All methods that try to modify the question_attempt throw exceptions.
*
* @copyright 2010 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_with_restricted_history extends question_attempt {
/**
* @var question_attempt the underlying question_attempt.
*/
protected $baseqa;
/**
* Create a question_attempt_with_restricted_history
* @param question_attempt $baseqa The question_attempt to make a restricted version of.
* @param integer $lastseq the index of the last step to include.
* @param string $preferredbehaviour the preferred behaviour. It is slightly
* annoyting that this needs to be passed, but unavoidable for now.
*/
public function __construct(question_attempt $baseqa, $lastseq, $preferredbehaviour) {
if ($lastseq < 0 || $lastseq >= $baseqa->get_num_steps()) {
throw new coding_exception('$seq out of range', $seq);
}
$this->baseqa = $baseqa;
$this->steps = array_slice($baseqa->steps, 0, $lastseq + 1);
$this->observer = new question_usage_null_observer();
// This should be a straight copy of all the remaining fields.
$this->id = $baseqa->id;
$this->usageid = $baseqa->usageid;
$this->slot = $baseqa->slot;
$this->question = $baseqa->question;
$this->maxmark = $baseqa->maxmark;
$this->minfraction = $baseqa->minfraction;
$this->questionsummary = $baseqa->questionsummary;
$this->responsesummary = $baseqa->responsesummary;
$this->rightanswer = $baseqa->rightanswer;
$this->flagged = $baseqa->flagged;
// Except behaviour, where we need to create a new one.
$this->behaviour = question_engine::make_behaviour(
$baseqa->get_behaviour_name(), $this, $preferredbehaviour);
}
public function get_full_step_iterator() {
return $this->baseqa->get_step_iterator();
}
protected function add_step(question_attempt_step $step) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function process_action($submitteddata, $timestamp = null, $userid = null) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function start($preferredbehaviour, $submitteddata = array(), $timestamp = null, $userid = null) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_database_id($id) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_flagged($flagged) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_number_in_usage($slot) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_question_summary($questionsummary) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
public function set_usage_id($usageid) {
coding_exception('Cannot modify a question_attempt_with_restricted_history.');
}
}
/**
* A class abstracting access to the {@link question_attempt::$states} array.
*
* This is actively linked to question_attempt. If you add an new step
* mid-iteration, then it will be included.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_step_iterator implements Iterator, ArrayAccess {
/** @var question_attempt the question_attempt being iterated over. */
protected $qa;
/** @var integer records the current position in the iteration. */
protected $i;
/**
* Do not call this constructor directly.
* Use {@link question_attempt::get_step_iterator()}.
* @param question_attempt $qa the attempt to iterate over.
*/
public function __construct(question_attempt $qa) {
$this->qa = $qa;
$this->rewind();
}
/** @return question_attempt_step */
public function current() {
return $this->offsetGet($this->i);
}
/** @return integer */
public function key() {
return $this->i;
}
public function next() {
++$this->i;
}
public function rewind() {
$this->i = 0;
}
/** @return boolean */
public function valid() {
return $this->offsetExists($this->i);
}
/** @return boolean */
public function offsetExists($i) {
return $i >= 0 && $i < $this->qa->get_num_steps();
}
/** @return question_attempt_step */
public function offsetGet($i) {
return $this->qa->get_step($i);
}
public function offsetSet($offset, $value) {
throw new Exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot set.');
}
public function offsetUnset($offset) {
throw new Exception('You are only allowed read-only access to question_attempt::states through a question_attempt_step_iterator. Cannot unset.');
}
}
/**
* A variant of {@link question_attempt_step_iterator} that iterates through the
* steps in reverse order.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_reverse_step_iterator extends question_attempt_step_iterator {
public function next() {
--$this->i;
}
public function rewind() {
$this->i = $this->qa->get_num_steps() - 1;
}
}
/**
* Stores one step in a {@link question_attempt}.
*
* The most important attributes of a step are the state, which is one of the
* {@link question_state} constants, the fraction, which may be null, or a
* number bewteen the attempt's minfraction and 1.0, and the array of submitted
* data, about which more later.
*
* A step also tracks the time it was created, and the user responsible for
* creating it.
*
* The submitted data is basically just an array of name => value pairs, with
* certain conventions about the to divide the variables into four = two times two
* categories.
*
* Variables may either belong to the behaviour, in which case the
* name starts with a '-', or they may belong to the question type in which case
* they name does not start with a '-'.
*
* Second, variables may either be ones that came form the original request, in
* which case the name does not start with an _, or they are cached values that
* were created during processing, in which case the name does start with an _.
*
* That is, each name will start with one of '', '_'. '-' or '-_'. The remainder
* of the name should match the regex [a-z][a-z0-9]*.
*
* These variables can be accessed with {@link get_behaviour_var()} and {@link get_qt_var()},
* - to be clear, ->get_behaviour_var('x') gets the variable with name '-x' -
* and values whose names start with '_' can be set using {@link set_behaviour_var()}
* and {@link set_qt_var()}. There are some other methods like {@link has_behaviour_var()}
* to check wether a varaible with a particular name is set, and {@link get_behaviour_data()}
* to get all the behaviour data as an associative array.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_step {
/** @var integer if this attempts is stored in the question_attempts table, the id of that row. */
private $id = null;
/** @var question_state one of the {@link question_state} constants. The state after this step. */
private $state;
/** @var null|number the fraction (grade on a scale of minfraction .. 1.0) or null. */
private $fraction = null;
/** @var integer the timestamp when this step was created. */
private $timecreated;
/** @var integer the id of the user resonsible for creating this step. */
private $userid;
/** @var array name => value pairs. The submitted data. */
private $data;
/**
* You should not need to call this constructor in your own code. Steps are
* normally created by {@link question_attempt} methods like
* {@link question_attempt::process_action()}.
* @param array $data the submitted data that defines this step.
* @param integer $timestamp the time to record for the action. (If not given, use now.)
* @param integer $userid the user to attribute the aciton to. (If not given, use the current user.)
*/
public function __construct($data = array(), $timecreated = null, $userid = null) {
global $USER;
$this->state = question_state::$unprocessed;
$this->data = $data;
if (is_null($timecreated)) {
$this->timecreated = time();
} else {
$this->timecreated = $timecreated;
}
if (is_null($userid)) {
$this->userid = $USER->id;
} else {
$this->userid = $userid;
}
}
/** @return question_state The state after this step. */
public function get_state() {
return $this->state;
}
/**
* Set the state. Normally only called by behaviours.
* @param question_state $state one of the {@link question_state} constants.
*/
public function set_state($state) {
$this->state = $state;
}
/**
* @return null|number the fraction (grade on a scale of minfraction .. 1.0)
* or null if this step has not been marked.
*/
public function get_fraction() {
return $this->fraction;
}
/**
* Set the fraction. Normally only called by behaviours.
* @param null|number $fraction the fraction to set.
*/
public function set_fraction($fraction) {
$this->fraction = $fraction;
}
/** @return integer the id of the user resonsible for creating this step. */
public function get_user_id() {
return $this->userid;
}
/** @return integer the timestamp when this step was created. */
public function get_timecreated() {
return $this->timecreated;
}
/**
* @param string $name the name of a question type variable to look for in the submitted data.
* @return boolean whether a variable with this name exists in the question type data.
*/
public function has_qt_var($name) {
return array_key_exists($name, $this->data);
}
/**
* @param string $name the name of a question type variable to look for in the submitted data.
* @return string the requested variable, or null if the variable is not set.
*/
public function get_qt_var($name) {
if (!$this->has_qt_var($name)) {
return null;
}
return $this->data[$name];
}
/**
* Set a cached question type variable.
* @param string $name the name of the variable to set. Must match _[a-z][a-z0-9]*.
* @param string $value the value to set.
*/
public function set_qt_var($name, $value) {
if ($name[0] != '_') {
throw new Exception('Cannot set question type data ' . $name . ' on an attempt step. You can only set variables with names begining with _.');
}
$this->data[$name] = $value;
}
/**
* Get all the question type variables.
* @param array name => value pairs.
*/
public function get_qt_data() {
$result = array();
foreach ($this->data as $name => $value) {
if ($name[0] != '-' && $name[0] != ':') {
$result[$name] = $value;
}
}
return $result;
}
/**
* @param string $name the name of an behaviour variable to look for in the submitted data.
* @return boolean whether a variable with this name exists in the question type data.
*/
public function has_behaviour_var($name) {
return array_key_exists('-' . $name, $this->data);
}
/**
* @param string $name the name of an behaviour variable to look for in the submitted data.
* @return string the requested variable, or null if the variable is not set.
*/
public function get_behaviour_var($name) {
if (!$this->has_behaviour_var($name)) {
return null;
}
return $this->data['-' . $name];
}
/**
* Set a cached behaviour variable.
* @param string $name the name of the variable to set. Must match _[a-z][a-z0-9]*.
* @param string $value the value to set.
*/
public function set_behaviour_var($name, $value) {
if ($name[0] != '_') {
throw new Exception('Cannot set question type data ' . $name . ' on an attempt step. You can only set variables with names begining with _.');
}
return $this->data['-' . $name] = $value;
}
/**
* Get all the behaviour variables.
* @param array name => value pairs.
*/
public function get_behaviour_data() {
$result = array();
foreach ($this->data as $name => $value) {
if ($name[0] == '-') {
$result[substr($name, 1)] = $value;
}
}
return $result;
}
/**
* Get all the submitted data, but not the cached data. behaviour
* variables have the - at the start of their name. This is only really
* intended for use by {@link question_attempt::regrade()}, it should not
* be considered part of the public API.
* @param array name => value pairs.
*/
public function get_submitted_data() {
$result = array();
foreach ($this->data as $name => $value) {
if ($name[0] == '_' || ($name[0] == '-' && $name[1] == '_')) {
continue;
}
$result[$name] = $value;
}
return $result;
}
/**
* Get all the data. behaviour variables have the ! at the start of
* their name. This is only intended for internal use, for example by
* {@link question_engine_data_mapper::insert_question_attempt_step()},
* however, it can ocasionally be useful in test code. It should not be
* considered part of the public API of this class.
* @param array name => value pairs.
*/
public function get_all_data() {
return $this->data;
}
/**
* Create a question_attempt_step from records loaded from the database.
* @param array $records Raw records loaded from the database.
* @param integer $stepid The id of the records to extract.
* @return question_attempt_step The newly constructed question_attempt_step.
*/
public static function load_from_records(&$records, $attemptstepid) {
$currentrec = current($records);
while ($currentrec->attemptstepid != $attemptstepid) {
$currentrec = next($records);
if (!$currentrec) {
throw new Exception("Question attempt step $attemptstepid not found in the database.");
}
}
$record = $currentrec;
$data = array();
while ($currentrec && $currentrec->attemptstepid == $attemptstepid) {
if ($currentrec->name) {
$data[$currentrec->name] = $currentrec->value;
}
$currentrec = next($records);
}
$step = new question_attempt_step_read_only($data, $record->timecreated, $record->userid);
$step->state = question_state::get($record->state);
if (!is_null($record->fraction)) {
$step->fraction = $record->fraction + 0;
}
return $step;
}
}
/**
* A subclass with a bit of additional funcitonality, for pending steps.
*
* @copyright 2010 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_pending_step extends question_attempt_step {
/** @var string . */
protected $newresponsesummary = null;
/**
* If as a result of processing this step, the response summary for the
* question attempt should changed, you should call this method to set the
* new summary.
* @param string $responsesummary the new response summary.
*/
public function set_new_response_summary($responsesummary) {
$this->newresponsesummary = $responsesummary;
}
/** @return string the new response summary, if any. */
public function get_new_response_summary() {
return $this->newresponsesummary;
}
/** @return string whether this step changes the response summary. */
public function response_summary_changed() {
return !is_null($this->newresponsesummary);
}
}
/**
* A subclass of {@link question_attempt_step} that cannot be modified.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_attempt_step_read_only extends question_attempt_step {
public function set_state($state) {
throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
}
public function set_fraction($fraction) {
throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
}
public function set_qt_var($name, $value) {
throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
}
public function set_behaviour_var($name, $value) {
throw new coding_exception('Cannot modify a question_attempt_step_read_only.');
}
}
/**
* A null {@link question_attempt_step} returned from
* {@link question_attempt::get_last_step()} etc. when a an attempt has just been
* created and there is no acutal step.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_null_step {
public function get_state() {
return question_state::$notstarted;
}
public function set_state($state) {
throw new Exception('This question has not been started.');
}
public function get_fraction() {
return null;
}
}
/**
* Interface for things that want to be notified of signficant changes to a
* {@link question_usage_by_activity}.
*
* A question behaviour controls the flow of actions a student can
* take as they work through a question, and later, as a teacher manually grades it.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
interface question_usage_observer {
/** Called when a field of the question_usage_by_activity is changed. */
public function notify_modified();
/**
* Called when the fields of a question attempt in this usage are modified.
* @param question_attempt $qa the newly added question attempt.
*/
public function notify_attempt_modified(question_attempt $qa);
/**
* Called when a new question attempt is added to this usage.
* @param question_attempt $qa the newly added question attempt.
*/
public function notify_attempt_added(question_attempt $qa);
/**
* Called we want to delete the old step records for an attempt, prior to
* inserting newones. This is used by regrading.
* @param question_attempt $qa the question attempt to delete the steps for.
*/
public function notify_delete_attempt_steps(question_attempt $qa);
/**
* Called when a new step is added to a question attempt in this usage.
* @param $step the new step.
* @param $qa the usage it is being added to.
* @param $seq the sequence number of the new step.
*/
public function notify_step_added(question_attempt_step $step, question_attempt $qa, $seq);
}
/**
* Null implmentation of the {@link question_usage_watcher} interface.
* Does nothing.
*
* @copyright 2009 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_usage_null_observer implements question_usage_observer {
public function notify_modified() {
}
public function notify_attempt_modified(question_attempt $qa) {
}
public function notify_attempt_added(question_attempt $qa) {
}
public function notify_delete_attempt_steps(question_attempt $qa) {
}
public function notify_step_added(question_attempt_step $step, question_attempt $qa, $seq) {
}
}
/**
* Useful functions for writing question types and behaviours.
*
* @copyright 2010 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
abstract class question_utils {
/**
* Tests to see whether two arrays have the same keys, with the same values
* (as compared by ===) for each key. However, the order of the arrays does
* not have to be the same.
* @param array $array1 the first array.
* @param array $array2 the second array.
* @return boolean whether the two arrays have the same keys with the same
* corresponding values.
*/
public static function arrays_have_same_keys_and_values(array $array1, array $array2) {
if (count($array1) != count($array2)) {
return false;
}
foreach ($array1 as $key => $value1) {
if (!array_key_exists($key, $array2)) {
return false;
}
if (((string) $value1) !== ((string) $array2[$key])) {
return false;
}
}
return true;
}
/**
* Tests to see whether two arrays have the same value at a particular key.
* This method will return true if:
* 1. Neither array contains the key; or
* 2. Both arrays contain the key, and the corresponding values compare
* identical when cast to strings and compared with ===.
* @param array $array1 the first array.
* @param array $array2 the second array.
* @param string $key an array key.
* @return boolean whether the two arrays have the same value (or lack of
* one) for a given key.
*/
public static function arrays_same_at_key(array $array1, array $array2, $key) {
if (array_key_exists($key, $array1) && array_key_exists($key, $array2)) {
return ((string) $array1[$key]) === ((string) $array2[$key]);
}
if (!array_key_exists($key, $array1) && !array_key_exists($key, $array2)) {
return true;
}
return false;
}
/**
* Tests to see whether two arrays have the same value at a particular key.
* Missing values are replaced by '', and then the values are cast to
* strings and compared with ===.
* @param array $array1 the first array.
* @param array $array2 the second array.
* @param string $key an array key.
* @return boolean whether the two arrays have the same value (or lack of
* one) for a given key.
*/
public static function arrays_same_at_key_missing_is_blank(
array $array1, array $array2, $key) {
if (array_key_exists($key, $array1)) {
$value1 = $array1[$key];
} else {
$value1 = '';
}
if (array_key_exists($key, $array2)) {
$value2 = $array2[$key];
} else {
$value2 = '';
}
return ((string) $value1) === ((string) $value2);
}
/**
* Tests to see whether two arrays have the same value at a particular key.
* Missing values are replaced by 0, and then the values are cast to
* integers and compared with ===.
* @param array $array1 the first array.
* @param array $array2 the second array.
* @param string $key an array key.
* @return boolean whether the two arrays have the same value (or lack of
* one) for a given key.
*/
public static function arrays_same_at_key_integer(
array $array1, array $array2, $key) {
if (array_key_exists($key, $array1)) {
$value1 = $array1[$key];
} else {
$value1 = 0;
}
if (array_key_exists($key, $array2)) {
$value2 = $array2[$key];
} else {
$value2 = 0;
}
return ((integer) $value1) === ((integer) $value2);
}
private static $units = array('', 'i', 'ii', 'iii', 'iv', 'v', 'vi', 'vii', 'viii', 'ix');
private static $tens = array('', 'x', 'xx', 'xxx', 'xl', 'l', 'lx', 'lxx', 'lxxx', 'xc');
private static $hundreds = array('', 'c', 'cc', 'ccc', 'cd', 'd', 'dc', 'dcc', 'dccc', 'cm');
private static $thousands = array('', 'm', 'mm', 'mmm');
/**
* Convert an integer to roman numerals.
* @param integer $number an integer between 1 and 3999 inclusive. Anything else will throw an exception.
* @return string the number converted to lower case roman numerals.
*/
public static function int_to_roman($number) {
if (!is_integer($number) || $number < 1 || $number > 3999) {
throw new coding_exception('Only integers between 0 and 3999 can be ' .
'converted to roman numerals.', $number);
}
return self::$thousands[$number / 1000 % 10] . self::$hundreds[$number / 100 % 10] .
self::$tens[$number / 10 % 10] . self::$units[$number % 10];
}
}