moodle/question/format.php
Tim Hunt 55190d7e2c MDL-20538 get rid of badly name-spaced constants from lib/questionlib.php.
Unfortunately, they are used all over the import/export code, so I cannot eliminate them completely. However, I was able to move them out of the core library.
2011-06-09 19:27:36 +01:00

898 lines
30 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/>.
/**
* Defines the base class for question import and export formats.
*
* @package moodlecore
* @subpackage questionbank
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**#@+
* The core question types.
*
* These used to be in lib/questionlib.php, but are being deprecated. Copying
* them here to keep the import/export code working for now (there are 135
* references to these constants which I don't want to try to fix at the moment.)
*/
if (!defined('SHORTANSWER')) {
define("SHORTANSWER", "shortanswer");
define("TRUEFALSE", "truefalse");
define("MULTICHOICE", "multichoice");
define("RANDOM", "random");
define("MATCH", "match");
define("RANDOMSAMATCH", "randomsamatch");
define("DESCRIPTION", "description");
define("NUMERICAL", "numerical");
define("MULTIANSWER", "multianswer");
define("CALCULATED", "calculated");
define("ESSAY", "essay");
}
/**#@-*/
/**
* Base class for question import and export formats.
*
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class qformat_default {
public $displayerrors = true;
public $category = null;
public $questions = array();
public $course = null;
public $filename = '';
public $realfilename = '';
public $matchgrades = 'error';
public $catfromfile = 0;
public $contextfromfile = 0;
public $cattofile = 0;
public $contexttofile = 0;
public $questionids = array();
public $importerrors = 0;
public $stoponerror = true;
public $translator = null;
public $canaccessbackupdata = true;
protected $importcontext = null;
// functions to indicate import/export functionality
// override to return true if implemented
/** @return bool whether this plugin provides import functionality. */
public function provide_import() {
return false;
}
/** @return bool whether this plugin provides export functionality. */
public function provide_export() {
return false;
}
/** The string mime-type of the files that this plugin reads or writes. */
public function mime_type() {
return mimeinfo('type', $this->export_file_extension());
}
/**
* @return string the file extension (including .) that is normally used for
* files handled by this plugin.
*/
public function export_file_extension() {
return '.txt';
}
// Accessor methods
/**
* set the category
* @param object category the category object
*/
public function setCategory($category) {
if (count($this->questions)) {
debugging('You shouldn\'t call setCategory after setQuestions');
}
$this->category = $category;
}
/**
* Set the specific questions to export. Should not include questions with
* parents (sub questions of cloze question type).
* Only used for question export.
* @param array of question objects
*/
public function setQuestions($questions) {
if ($this->category !== null) {
debugging('You shouldn\'t call setQuestions after setCategory');
}
$this->questions = $questions;
}
/**
* set the course class variable
* @param course object Moodle course variable
*/
public function setCourse($course) {
$this->course = $course;
}
/**
* set an array of contexts.
* @param array $contexts Moodle course variable
*/
public function setContexts($contexts) {
$this->contexts = $contexts;
$this->translator = new context_to_string_translator($this->contexts);
}
/**
* set the filename
* @param string filename name of file to import/export
*/
public function setFilename($filename) {
$this->filename = $filename;
}
/**
* set the "real" filename
* (this is what the user typed, regardless of wha happened next)
* @param string realfilename name of file as typed by user
*/
public function setRealfilename($realfilename) {
$this->realfilename = $realfilename;
}
/**
* set matchgrades
* @param string matchgrades error or nearest for grades
*/
public function setMatchgrades($matchgrades) {
$this->matchgrades = $matchgrades;
}
/**
* set catfromfile
* @param bool catfromfile allow categories embedded in import file
*/
public function setCatfromfile($catfromfile) {
$this->catfromfile = $catfromfile;
}
/**
* set contextfromfile
* @param bool $contextfromfile allow contexts embedded in import file
*/
public function setContextfromfile($contextfromfile) {
$this->contextfromfile = $contextfromfile;
}
/**
* set cattofile
* @param bool cattofile exports categories within export file
*/
public function setCattofile($cattofile) {
$this->cattofile = $cattofile;
}
/**
* set contexttofile
* @param bool cattofile exports categories within export file
*/
public function setContexttofile($contexttofile) {
$this->contexttofile = $contexttofile;
}
/**
* set stoponerror
* @param bool stoponerror stops database write if any errors reported
*/
public function setStoponerror($stoponerror) {
$this->stoponerror = $stoponerror;
}
/**
* @param bool $canaccess Whether the current use can access the backup data folder. Determines
* where export files are saved.
*/
public function set_can_access_backupdata($canaccess) {
$this->canaccessbackupdata = $canaccess;
}
/***********************
* IMPORTING FUNCTIONS
***********************/
/**
* Handle parsing error
*/
protected function error($message, $text='', $questionname='') {
$importerrorquestion = get_string('importerrorquestion', 'question');
echo "<div class=\"importerror\">\n";
echo "<strong>$importerrorquestion $questionname</strong>";
if (!empty($text)) {
$text = s($text);
echo "<blockquote>$text</blockquote>\n";
}
echo "<strong>$message</strong>\n";
echo "</div>";
$this->importerrors++;
}
/**
* Import for questiontype plugins
* Do not override.
* @param data mixed The segment of data containing the question
* @param question object processed (so far) by standard import code if appropriate
* @param extra mixed any additional format specific data that may be passed by the format
* @param qtypehint hint about a question type from format
* @return object question object suitable for save_options() or false if cannot handle
*/
public function try_importing_using_qtypes($data, $question = null, $extra = null,
$qtypehint = '') {
// work out what format we are using
$formatname = substr(get_class($this), strlen('qformat_'));
$methodname = "import_from_$formatname";
//first try importing using a hint from format
if (!empty($qtypehint)) {
$qtype = question_bank::get_qtype($qtypehint, false);
if (is_object($qtype) && method_exists($qtype, $methodname)) {
$question = $qtype->$methodname($data, $question, $this, $extra);
if ($question) {
return $question;
}
}
}
// loop through installed questiontypes checking for
// function to handle this question
foreach (question_bank::get_all_qtypes() as $qtype) {
if (method_exists($qtype, $methodname)) {
if ($question = $qtype->$methodname($data, $question, $this, $extra)) {
return $question;
}
}
}
return false;
}
/**
* Perform any required pre-processing
* @return bool success
*/
public function importpreprocess() {
return true;
}
/**
* Process the file
* This method should not normally be overidden
* @param object $category
* @return bool success
*/
public function importprocess($category) {
global $USER, $CFG, $DB, $OUTPUT;
$context = $category->context;
$this->importcontext = $context;
// reset the timer in case file upload was slow
set_time_limit(0);
// STAGE 1: Parse the file
echo $OUTPUT->notification(get_string('parsingquestions', 'question'), 'notifysuccess');
if (! $lines = $this->readdata($this->filename)) {
echo $OUTPUT->notification(get_string('cannotread', 'question'));
return false;
}
if (!$questions = $this->readquestions($lines, $context)) { // Extract all the questions
echo $OUTPUT->notification(get_string('noquestionsinfile', 'question'));
return false;
}
// STAGE 2: Write data to database
echo $OUTPUT->notification(get_string('importingquestions', 'question',
$this->count_questions($questions)), 'notifysuccess');
// check for errors before we continue
if ($this->stoponerror and ($this->importerrors>0)) {
echo $OUTPUT->notification(get_string('importparseerror', 'question'));
return true;
}
// get list of valid answer grades
$gradeoptionsfull = question_bank::fraction_options_full();
// check answer grades are valid
// (now need to do this here because of 'stop on error': MDL-10689)
$gradeerrors = 0;
$goodquestions = array();
foreach ($questions as $question) {
if (!empty($question->fraction) and (is_array($question->fraction))) {
$fractions = $question->fraction;
$answersvalid = true; // in case they are!
foreach ($fractions as $key => $fraction) {
$newfraction = match_grade_options($gradeoptionsfull, $fraction,
$this->matchgrades);
if ($newfraction === false) {
$answersvalid = false;
} else {
$fractions[$key] = $newfraction;
}
}
if (!$answersvalid) {
echo $OUTPUT->notification(get_string('invalidgrade', 'question'));
++$gradeerrors;
continue;
} else {
$question->fraction = $fractions;
}
}
$goodquestions[] = $question;
}
$questions = $goodquestions;
// check for errors before we continue
if ($this->stoponerror && $gradeerrors > 0) {
return false;
}
// count number of questions processed
$count = 0;
foreach ($questions as $question) { // Process and store each question
// reset the php timeout
set_time_limit(0);
// check for category modifiers
if ($question->qtype == 'category') {
if ($this->catfromfile) {
// find/create category object
$catpath = $question->category;
$newcategory = $this->create_category_path($catpath);
if (!empty($newcategory)) {
$this->category = $newcategory;
}
}
continue;
}
$question->context = $context;
$count++;
echo "<hr /><p><b>$count</b>. ".$this->format_question_text($question)."</p>";
$question->category = $this->category->id;
$question->stamp = make_unique_id_code(); // Set the unique code (not to be changed)
$question->createdby = $USER->id;
$question->timecreated = time();
$question->id = $DB->insert_record('question', $question);
if (isset($question->questiontextfiles)) {
foreach ($question->questiontextfiles as $file) {
question_bank::get_qtype($question->qtype)->import_file(
$context, 'question', 'questiontext', $question->id, $file);
}
}
if (isset($question->generalfeedbackfiles)) {
foreach ($question->generalfeedbackfiles as $file) {
question_bank::get_qtype($question->qtype)->import_file(
$context, 'question', 'generalfeedback', $question->id, $file);
}
}
$this->questionids[] = $question->id;
// Now to save all the answers and type-specific options
$result = question_bank::get_qtype($question->qtype)->save_question_options($question);
if (!empty($CFG->usetags) && isset($question->tags)) {
require_once($CFG->dirroot . '/tag/lib.php');
tag_set('question', $question->id, $question->tags);
}
if (!empty($result->error)) {
echo $OUTPUT->notification($result->error);
return false;
}
if (!empty($result->notice)) {
echo $OUTPUT->notification($result->notice);
return true;
}
// Give the question a unique version stamp determined by question_hash()
$DB->set_field('question', 'version', question_hash($question),
array('id' => $question->id));
}
return true;
}
/**
* Count all non-category questions in the questions array.
*
* @param array questions An array of question objects.
* @return int The count.
*
*/
protected function count_questions($questions) {
$count = 0;
if (!is_array($questions)) {
return $count;
}
foreach ($questions as $question) {
if (!is_object($question) || !isset($question->qtype) ||
($question->qtype == 'category')) {
continue;
}
$count++;
}
return $count;
}
/**
* find and/or create the category described by a delimited list
* e.g. $course$/tom/dick/harry or tom/dick/harry
*
* removes any context string no matter whether $getcontext is set
* but if $getcontext is set then ignore the context and use selected category context.
*
* @param string catpath delimited category path
* @param int courseid course to search for categories
* @return mixed category object or null if fails
*/
protected function create_category_path($catpath) {
global $DB;
$catnames = $this->split_category_path($catpath);
$parent = 0;
$category = null;
// check for context id in path, it might not be there in pre 1.9 exports
$matchcount = preg_match('/^\$([a-z]+)\$$/', $catnames[0], $matches);
if ($matchcount == 1) {
$contextid = $this->translator->string_to_context($matches[1]);
array_shift($catnames);
} else {
$contextid = false;
}
if ($this->contextfromfile && $contextid !== false) {
$context = get_context_instance_by_id($contextid);
require_capability('moodle/question:add', $context);
} else {
$context = get_context_instance_by_id($this->category->contextid);
}
// Now create any categories that need to be created.
foreach ($catnames as $catname) {
if ($category = $DB->get_record('question_categories',
array('name' => $catname, 'contextid' => $context->id, 'parent' => $parent))) {
$parent = $category->id;
} else {
require_capability('moodle/question:managecategory', $context);
// create the new category
$category = new stdClass();
$category->contextid = $context->id;
$category->name = $catname;
$category->info = '';
$category->parent = $parent;
$category->sortorder = 999;
$category->stamp = make_unique_id_code();
$id = $DB->insert_record('question_categories', $category);
$category->id = $id;
$parent = $id;
}
}
return $category;
}
/**
* Return complete file within an array, one item per line
* @param string filename name of file
* @return mixed contents array or false on failure
*/
protected function readdata($filename) {
if (is_readable($filename)) {
$filearray = file($filename);
/// Check for Macintosh OS line returns (ie file on one line), and fix
if (preg_match("~\r~", $filearray[0]) AND !preg_match("~\n~", $filearray[0])) {
return explode("\r", $filearray[0]);
} else {
return $filearray;
}
}
return false;
}
/**
* Parses an array of lines into an array of questions,
* where each item is a question object as defined by
* readquestion(). Questions are defined as anything
* between blank lines.
*
* If your format does not use blank lines as a delimiter
* then you will need to override this method. Even then
* try to use readquestion for each question
* @param array lines array of lines from readdata
* @param object $context
* @return array array of question objects
*/
protected function readquestions($lines, $context) {
$questions = array();
$currentquestion = array();
foreach ($lines as $line) {
$line = trim($line);
if (empty($line)) {
if (!empty($currentquestion)) {
if ($question = $this->readquestion($currentquestion)) {
$questions[] = $question;
}
$currentquestion = array();
}
} else {
$currentquestion[] = $line;
}
}
if (!empty($currentquestion)) { // There may be a final question
if ($question = $this->readquestion($currentquestion, $context)) {
$questions[] = $question;
}
}
return $questions;
}
/**
* return an "empty" question
* Somewhere to specify question parameters that are not handled
* by import but are required db fields.
* This should not be overridden.
* @return object default question
*/
protected function defaultquestion() {
global $CFG;
static $defaultshuffleanswers = null;
if (is_null($defaultshuffleanswers)) {
$defaultshuffleanswers = get_config('quiz', 'shuffleanswers');
}
$question = new stdClass();
$question->shuffleanswers = $defaultshuffleanswers;
$question->defaultmark = 1;
$question->image = "";
$question->usecase = 0;
$question->multiplier = array();
$question->generalfeedback = '';
$question->correctfeedback = '';
$question->partiallycorrectfeedback = '';
$question->incorrectfeedback = '';
$question->answernumbering = 'abc';
$question->penalty = 0.3333333;
$question->length = 1;
// this option in case the questiontypes class wants
// to know where the data came from
$question->export_process = true;
$question->import_process = true;
return $question;
}
/**
* Given the data known to define a question in
* this format, this function converts it into a question
* object suitable for processing and insertion into Moodle.
*
* If your format does not use blank lines to delimit questions
* (e.g. an XML format) you must override 'readquestions' too
* @param $lines mixed data that represents question
* @return object question object
*/
protected function readquestion($lines) {
$formatnotimplemented = get_string('formatnotimplemented', 'question');
echo "<p>$formatnotimplemented</p>";
return null;
}
/**
* Override if any post-processing is required
* @return bool success
*/
public function importpostprocess() {
return true;
}
/*******************
* EXPORT FUNCTIONS
*******************/
/**
* Provide export functionality for plugin questiontypes
* Do not override
* @param name questiontype name
* @param question object data to export
* @param extra mixed any addition format specific data needed
* @return string the data to append to export or false if error (or unhandled)
*/
protected function try_exporting_using_qtypes($name, $question, $extra=null) {
// work out the name of format in use
$formatname = substr(get_class($this), strlen('qformat_'));
$methodname = "export_to_$formatname";
$qtype = question_bank::get_qtype($name, false);
if (method_exists($qtype, $methodname)) {
return $qtype->$methodname($question, $this, $extra);
}
return false;
}
/**
* Do any pre-processing that may be required
* @param bool success
*/
public function exportpreprocess() {
return true;
}
/**
* Enable any processing to be done on the content
* just prior to the file being saved
* default is to do nothing
* @param string output text
* @param string processed output text
*/
protected function presave_process($content) {
return $content;
}
/**
* Do the export
* For most types this should not need to be overrided
* @return stored_file
*/
public function exportprocess() {
global $CFG, $OUTPUT, $DB, $USER;
// get the questions (from database) in this category
// only get q's with no parents (no cloze subquestions specifically)
if ($this->category) {
$questions = get_questions_category($this->category, true);
} else {
$questions = $this->questions;
}
$count = 0;
// results are first written into string (and then to a file)
// so create/initialize the string here
$expout = "";
// track which category questions are in
// if it changes we will record the category change in the output
// file if selected. 0 means that it will get printed before the 1st question
$trackcategory = 0;
// iterate through questions
foreach ($questions as $question) {
// used by file api
$contextid = $DB->get_field('question_categories', 'contextid',
array('id' => $question->category));
$question->contextid = $contextid;
// do not export hidden questions
if (!empty($question->hidden)) {
continue;
}
// do not export random questions
if ($question->qtype == 'random') {
continue;
}
// check if we need to record category change
if ($this->cattofile) {
if ($question->category != $trackcategory) {
$trackcategory = $question->category;
$categoryname = $this->get_category_path($trackcategory, $this->contexttofile);
// create 'dummy' question for category export
$dummyquestion = new stdClass();
$dummyquestion->qtype = 'category';
$dummyquestion->category = $categoryname;
$dummyquestion->name = 'Switch category to ' . $categoryname;
$dummyquestion->id = 0;
$dummyquestion->questiontextformat = '';
$dummyquestion->contextid = 0;
$expout .= $this->writequestion($dummyquestion) . "\n";
}
}
// export the question displaying message
$count++;
if (question_has_capability_on($question, 'view', $question->category)) {
$expout .= $this->writequestion($question, $contextid) . "\n";
}
}
// continue path for following error checks
$course = $this->course;
$continuepath = "$CFG->wwwroot/question/export.php?courseid=$course->id";
// did we actually process anything
if ($count==0) {
print_error('noquestions', 'question', $continuepath);
}
// final pre-process on exported data
$expout = $this->presave_process($expout);
return $expout;
}
/**
* get the category as a path (e.g., tom/dick/harry)
* @param int id the id of the most nested catgory
* @return string the path
*/
protected function get_category_path($id, $includecontext = true) {
global $DB;
if (!$category = $DB->get_record('question_categories', array('id' => $id))) {
print_error('cannotfindcategory', 'error', '', $id);
}
$contextstring = $this->translator->context_to_string($category->contextid);
$pathsections = array();
do {
$pathsections[] = $category->name;
$id = $category->parent;
} while ($category = $DB->get_record('question_categories', array('id' => $id)));
if ($includecontext) {
$pathsections[] = '$' . $contextstring . '$';
}
$path = $this->assemble_category_path(array_reverse($pathsections));
return $path;
}
/**
* Convert a list of category names, possibly preceeded by one of the
* context tokens like $course$, into a string representation of the
* category path.
*
* Names are separated by / delimiters. And /s in the name are replaced by //.
*
* To reverse the process and split the paths into names, use
* {@link split_category_path()}.
*
* @param array $names
* @return string
*/
protected function assemble_category_path($names) {
$escapednames = array();
foreach ($names as $name) {
$escapedname = str_replace('/', '//', $name);
if (substr($escapedname, 0, 1) == '/') {
$escapedname = ' ' . $escapedname;
}
if (substr($escapedname, -1) == '/') {
$escapedname = $escapedname . ' ';
}
$escapednames[] = $escapedname;
}
return implode('/', $escapednames);
}
/**
* Convert a string, as returned by {@link assemble_category_path()},
* back into an array of category names.
*
* Each category name is cleaned by a call to clean_param(, PARAM_MULTILANG),
* which matches the cleaning in question/category_form.php.
*
* @param string $path
* @return array of category names.
*/
protected function split_category_path($path) {
$rawnames = preg_split('~(?<!/)/(?!/)~', $path);
$names = array();
foreach ($rawnames as $rawname) {
$names[] = clean_param(trim(str_replace('//', '/', $rawname)), PARAM_MULTILANG);
}
return $names;
}
/**
* Do an post-processing that may be required
* @return bool success
*/
protected function exportpostprocess() {
return true;
}
/**
* convert a single question object into text output in the given
* format.
* This must be overriden
* @param object question question object
* @return mixed question export text or null if not implemented
*/
protected function writequestion($question) {
// if not overidden, then this is an error.
$formatnotimplemented = get_string('formatnotimplemented', 'question');
echo "<p>$formatnotimplemented</p>";
return null;
}
/**
* Convert the question text to plain text, so it can safely be displayed
* during import to let the user see roughly what is going on.
*/
protected function format_question_text($question) {
global $DB;
$formatoptions = new stdClass();
$formatoptions->noclean = true;
return html_to_text(format_text($question->questiontext,
$question->questiontextformat, $formatoptions), 0, false);
}
/**
* convert files into text output in the given format.
* @param array
* @param string encoding method
* @return string $string
*/
protected function writefiles($files, $encoding='base64') {
if (empty($files)) {
return '';
}
$string = '';
foreach ($files as $file) {
if ($file->is_directory()) {
continue;
}
$string .= '<file name="' . $file->get_filename() . '" encoding="' . $encoding . '">';
$string .= base64_encode($file->get_content());
$string .= '</file>';
}
return $string;
}
}