moodle/mod/quiz/format.php

<?php  // $Id$ 

////////////////////////////////////////////////////////////////////
/// format.php  - Default format class for file imports/exports.  //
///                                                               //
/// Doesn't do everything on it's own -- it needs to be extended. //
////////////////////////////////////////////////////////////////////

// Included by import.php and export.php

class quiz_default_format {

    var $displayerrors = true;
    var $category = NULL;
    var $course = NULL;
    var $questionids = array();

/// Importing functions

    function importpreprocess($category) {
    /// Does any pre-processing that may be desired

        $this->category = $category;  // Important

        return true;
    }

    function importprocess($filename) {
    /// Processes a given file.  There's probably little need to change this

        if (! $lines = $this->readdata($filename)) {
            notify("File could not be read, or was empty");
            return false;
        }

        if (! $questions = $this->readquestions($lines)) {   // Extract all the questions
            notify("There are no questions in this file!");
            return false;
        }

        notify("Importing ".count($questions)." questions");

        $count = 0;

        foreach ($questions as $question) {   // Process and store each question
            $count++;

            echo "<hr /><p><b>$count</b>. ".stripslashes($question->questiontext)."</p>";

            $question->category = $this->category->id;
            $question->stamp = make_unique_id_code();  // Set the unique code (not to be changed)
            $question->version = 1;                    // Original version of this question

            if (!$question->id = insert_record("quiz_questions", $question)) {
                error("Could not insert new question!");
            }

            $this->questionids[] = $question->id;

            // Now to save all the answers and type-specific options

            global $QUIZ_QTYPES;
            $result = $QUIZ_QTYPES[$question->qtype]
                    ->save_question_options($question);

            if (!empty($result->error)) {
                notify($result->error);
                return false;
            }

            if (!empty($result->notice)) {
                notify($result->notice);
                return true;
            }
        }
        return true;
    }


    function readdata($filename) {
    /// Returns complete file with an array, one item per line

        if (is_readable($filename)) {
            $filearray = file($filename);

            /// Check for Macintosh OS line returns (ie file on one line), and fix
            if (ereg("\r", $filearray[0]) AND !ereg("\n", $filearray[0])) {
                return explode("\r", $filearray[0]);
            } else {
                return $filearray;
            }
        }
        return false;
    }

    function readquestions($lines) {
    /// 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.
     
        $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)) {
                $questions[] = $question;
            }
        }

        return $questions;
    }


    function readquestion($lines) {
    /// Given an array of lines known to define a question in 
    /// this format, this function converts it into a question 
    /// object suitable for processing and insertion into Moodle.

        echo "<p>This quiz format has not yet been completed!</p>";

        return NULL;
    }


    function importpostprocess() {
    /// Does any post-processing that may be desired
    /// Argument is a simple array of question ids that 
    /// have just been added.

        return true;
    }

// Export functions


    function export_file_extension() {
    /// return the files extension appropriate for this type
    /// override if you don't want .txt
  
        return ".txt";
    }

    function exportpreprocess($category, $course) {
    /// Does any pre-processing that may be desired

        $this->category = $category;  // Important
        $this->course = $course; // As is this!

        return true;
    }

    function presave_process( $content ) {
    /// enables any processing to be done on the content
    /// just prior to the file being saved
    /// default is to do nothing
 
        return $content;
    }

    function exportprocess($filename) {
    /// Exports a given category.  There's probably little need to change this

        global $CFG;

        // create a directory for the exports (if not already existing)
        $dirname = get_string("exportfilename","quiz");
        $courseid = $this->course->id;
        $path = $CFG->dataroot.'/'.$courseid.'/'.$dirname;
        if (!is_dir($path)) {
            if (!mkdir($path, $CFG->directorypermissions)) {
              error("Cannot create path: $path");
            }
        }

        // get the questions (from database) in this category
        // $questions = get_records("quiz_questions","category",$this->category->id);
        $questions = get_questions_category( $this->category );

        notify("Exporting ".count($questions)." questions.");
        $count = 0;

        // results are first written into string (and then to a file)
        // so create/initialize the string here
        $expout = "";

        // iterate through questions
        foreach($questions as $question) {
          $count++;
          echo "<hr /><p><b>$count</b>. ".stripslashes($question->questiontext)."</p>";
          $expout .= $this->writequestion( $question ) . "\n";
          }

        // final pre-process on exported data
        $expout = $this->presave_process( $expout );

        // write file
        $filepath = $path."/".$filename . $this->export_file_extension();
        if (!$fh=fopen($filepath,"w")) {
            error("Cannot open for writing: $filepath");
        }
        if (!fwrite($fh, $expout)) {
            error("Cannot write exported questions to $filepath");
        }
        fclose($fh);

        return true;
    }

    function exportpostprocess() {
    /// Does any post-processing that may be desired

        return true;
    }

    function writequestion($question) {
    /// Turns a question object into textual output in the given format 
    /// must be overidden

        echo "<p>This quiz format has not yet been completed!</p>";

        return NULL;
    }

}

?>