first commit

question/format/gift/classes/privacy/provider.php

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+<?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/>.
+
+/**
+ * Privacy Subsystem implementation for qformat_gift.
+ *
+ * @package    qformat_gift
+ * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace qformat_gift\privacy;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Privacy Subsystem for qformat_gift implementing null_provider.
+ *
+ * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class provider implements \core_privacy\local\metadata\null_provider {
+
+    /**
+     * Get the language string identifier with the component's language
+     * file to explain why this plugin stores no data.
+     *
+     * @return  string
+     */
+    public static function get_reason(): string {
+        return 'privacy:metadata';
+    }
+}

question/format/gift/examples.txt

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+//  EXAMPLE QUESTIONS for the GIFT import filter
+//  by Paul Tsuchido Shew, January 2004.
+
+//-----------------------------------------//
+// Examples from the class description.
+//-----------------------------------------//
+
+Who's buried in Grant's tomb?{~Grant ~Jefferson =no one}
+
+Grant is {~buried =entombed ~living} in Grant's tomb.
+
+Grant is buried in Grant's tomb.{FALSE}
+
+Who's buried in Grant's tomb?{=no one =nobody}
+
+When was Ulysses S. Grant born?{#1822:1}
+
+
+//-----------------------------------------//
+// Examples from the documentation.
+//-----------------------------------------//
+
+// ===Multiple Choice===
+
+Who's buried in Grant's tomb?{~Grant ~Jefferson =no one}
+
+Grant is {~buried =entombed ~living} in Grant's tomb.
+
+The American holiday of Thanksgiving is celebrated on the {
+    ~second
+    ~third
+    =fourth
+} Thursday of November.
+
+Japanese characters originally came from what country? {
+    ~India
+    =China
+    ~Korea
+    ~Egypt}
+
+// ===Short Answer===
+
+Who's buried in Grant's tomb?{=no one =nobody}
+
+Two plus two equals {=four =4}.
+
+// ===True-False===
+
+Grant is buried in Grant's tomb.{F}
+
+The sun rises in the east.{T}
+
+// ===Matching===
+
+Matching Question. {
+    =subquestion1 -> subanswer1
+    =subquestion2 -> subanswer2
+    =subquestion3 -> subanswer3
+    }
+
+Match the following countries with their corresponding capitals. {
+    =Canada -> Ottawa
+    =Italy  -> Rome
+    =Japan  -> Tokyo
+    =India  -> New Delhi
+    }
+
+// ===Numerical===
+
+When was Ulysses S. Grant born? {#1822}
+
+What is the value of pi (to 3 decimal places)? {#3.1415:0.0005}.
+
+What is the value of pi (to 3 decimal places)? {#3.141..3.142}.
+
+When was Ulysses S. Grant born? {#
+    =1822:0
+    =%50%1822:2}
+
+// OPTIONS
+
+// ===Line Comments===
+
+// Subheading: Numerical questions below
+What's 2 plus 2? {#4}
+
+
+// ===Question Name===
+
+::Kanji Origins::Japanese characters originally
+came from what country? {=China}
+
+::Thanksgiving Date::The American holiday of Thanksgiving is
+celebrated on the {~second ~third =fourth} Thursday of November.
+
+// ===Feedback===
+
+What's the answer to this multiple-choice question?{
+~wrong answer#feedback comment on the wrong answer
+~another wrong answer#feedback comment on this wrong answer
+=right answer#Very good!}
+
+Who's buried in Grant's tomb?{
+=no one#excellent answer!
+=nobody#excellent answer!}
+
+// ===Specify text format===
+[markdown]Who's buried in **Grant's tomb**?{
+=no one#excellent answer!
+=nobody#excellent answer!}
+
+// ===Percentage Answer Weights===
+Grant is buried in Grant's tomb.{FALSE#No one is buried in Grant's tomb.}
+
+Difficult question.{~wrong answer ~%50%half credit answer =full credit answer}
+
+::Jesus' hometown::Jesus Christ was from {
+    ~Jerusalem#This was an important city, but the wrong answer.
+    ~%25%Bethlehem#He was born here, but not raised here.
+    ~%50%Galilee#You need to be more specific.
+    =Nazareth#Yes! That's right!}.
+
+::Jesus' hometown:: Jesus Christ was from {
+    =Nazareth#Yes! That's right!
+    =%75%Nazereth#Right, but misspelled.
+    =%25%Bethlehem#He was born here, but not raised here.}
+
+// ===Multiple Answers===
+
+What two people are entombed in Grant's tomb? {
+    ~No one
+    ~%50%Grant
+    ~%50%Grant's wife
+    ~Grant's father }
+
+What two people are entombed in Grant's tomb? {
+    ~%-50%No one
+    ~%50%Grant
+    ~%50%Grant's wife
+    ~%-50%Grant's father }
+
+// ===Special Characters===
+Which answer equals 5? {
+     ~ \= 2 + 2
+     = \= 2 + 3
+     ~ \= 2 + 4  }
+
+::GIFT Control Characters::
+Which of the following is NOT a control character for the GIFT import format? {
+   ~ \~     # \~ is a control character.
+   ~ \=     # \= is a control character.
+   ~ \#     # \# is a control character.
+   ~ \{     # \{ is a control character.
+   ~ \}     # \} is a control character.
+   = \\     # Correct! \\ (backslash) is not a control character. BUT,
+              it is used to escape the control characters. So, to specify
+              a literal backslash, you must escape it with a backslash
+              (as shown in this example).
+}
+
+
+
+//-----------------------------------------//
+// Examples from gift/format.php.
+//-----------------------------------------//
+
+Who's buried in Grant's tomb?{~Grant ~Jefferson =no one}
+
+Grant is {~buried =entombed ~living} in Grant's tomb.
+
+Grant is buried in Grant's tomb.{FALSE}
+
+Who's buried in Grant's tomb?{=no one =nobody}
+
+When was Ulysses S. Grant born?{#1822:5}
+
+Match the following countries with their corresponding
+capitals.{=Canada->Ottawa =Italy->Rome =Japan->Tokyo}
+
+//-----------------------------------------//
+// More complicated examples.
+//-----------------------------------------//
+
+::Grant's Tomb::Grant is {
+      ~buried#No one is buried there.
+      =entombed#Right answer!
+      ~living#We hope not!
+} in Grant's tomb.
+
+Difficult multiple choice question.{
+     ~wrong answer           #comment on wrong answer
+     ~%50%half credit answer #comment on answer
+     =full credit answer     #well done!}
+
+::Jesus' hometown (Short answer ex.):: Jesus Christ was from {
+     =Nazareth#Yes! That's right!
+     =%75%Nazereth#Right, but misspelled.
+     =%25%Bethlehem#He was born here, but not raised here.
+}.
+
+//this comment will be ignored by the filter
+::Numerical example::
+When was Ulysses S. Grant born? {#
+     =1822:0      #Correct! 100% credit
+     =%50%1822:2  #He was born in 1822.
+                  You get 50% credit for being close.
+}

question/format/gift/format.php

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+<?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/>.
+
+/**
+ * GIFT format question importer/exporter.
+ *
+ * @package    qformat_gift
+ * @copyright  2003 Paul Tsuchido Shew
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+
+defined('MOODLE_INTERNAL') || die();
+
+
+/**
+ * The GIFT import filter was designed as an easy to use method
+ * for teachers writing questions as a text file. It supports most
+ * question types and the missing word format.
+ *
+ * Multiple Choice / Missing Word
+ *     Who's buried in Grant's tomb?{~Grant ~Jefferson =no one}
+ *     Grant is {~buried =entombed ~living} in Grant's tomb.
+ * True-False:
+ *     Grant is buried in Grant's tomb.{FALSE}
+ * Short-Answer.
+ *     Who's buried in Grant's tomb?{=no one =nobody}
+ * Numerical
+ *     When was Ulysses S. Grant born?{#1822:5}
+ * Matching
+ *     Match the following countries with their corresponding
+ *     capitals.{=Canada->Ottawa =Italy->Rome =Japan->Tokyo}
+ *
+ * Comment lines start with a double backslash (//).
+ * Optional question names are enclosed in double colon(::).
+ * Answer feedback is indicated with hash mark (#).
+ * Percentage answer weights immediately follow the tilde (for
+ * multiple choice) or equal sign (for short answer and numerical),
+ * and are enclosed in percent signs (% %). See docs and examples.txt for more.
+ *
+ * This filter was written through the collaboration of numerous
+ * members of the Moodle community. It was originally based on
+ * the missingword format, which included code from Thomas Robb
+ * and others. Paul Tsuchido Shew wrote this filter in December 2003.
+ *
+ * @copyright  2003 Paul Tsuchido Shew
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class qformat_gift extends qformat_default {
+
+    public function provide_import() {
+        return true;
+    }
+
+    public function provide_export() {
+        return true;
+    }
+
+    public function export_file_extension() {
+        return '.txt';
+    }
+
+    /**
+     * Validate the given file.
+     *
+     * For more expensive or detailed integrity checks.
+     *
+     * @param stored_file $file the file to check
+     * @return string the error message that occurred while validating the given file
+     */
+    public function validate_file(stored_file $file): string {
+        return $this->validate_is_utf8_file($file);
+    }
+
+    protected function answerweightparser(&$answer) {
+        $answer = substr($answer, 1);                        // Removes initial %.
+        $endposition  = strpos($answer, "%");
+        $answerweight = substr($answer, 0, $endposition);  // Gets weight as integer.
+        $answerweight = $answerweight/100;                 // Converts to percent.
+        $answer = substr($answer, $endposition+1);          // Removes comment from answer.
+        return $answerweight;
+    }
+
+    protected function commentparser($answer, $defaultformat) {
+        $bits = explode('#', $answer, 2);
+        $ans = $this->parse_text_with_format(trim($bits[0]), $defaultformat);
+        if (count($bits) > 1) {
+            $feedback = $this->parse_text_with_format(trim($bits[1]), $defaultformat);
+        } else {
+            $feedback = array('text' => '', 'format' => $defaultformat, 'files' => array());
+        }
+        return array($ans, $feedback);
+    }
+
+    protected function split_truefalse_comment($answer, $defaultformat) {
+        $bits = explode('#', $answer, 3);
+        $ans = $this->parse_text_with_format(trim($bits[0]), $defaultformat);
+        if (count($bits) > 1) {
+            $wrongfeedback = $this->parse_text_with_format(trim($bits[1]), $defaultformat);
+        } else {
+            $wrongfeedback = array('text' => '', 'format' => $defaultformat, 'files' => array());
+        }
+        if (count($bits) > 2) {
+            $rightfeedback = $this->parse_text_with_format(trim($bits[2]), $defaultformat);
+        } else {
+            $rightfeedback = array('text' => '', 'format' => $defaultformat, 'files' => array());
+        }
+        return array($ans, $wrongfeedback, $rightfeedback);
+    }
+
+    protected function escapedchar_pre($string) {
+        // Replaces escaped control characters with a placeholder BEFORE processing.
+
+        $escapedcharacters = array("\\:",    "\\#",    "\\=",    "\\{",    "\\}",    "\\~",    "\\n"  );
+        $placeholders      = array("&&058;", "&&035;", "&&061;", "&&123;", "&&125;", "&&126;", "&&010");
+
+        $string = str_replace("\\\\", "&&092;", $string);
+        $string = str_replace($escapedcharacters, $placeholders, $string);
+        $string = str_replace("&&092;", "\\", $string);
+        return $string;
+    }
+
+    protected function escapedchar_post($string) {
+        // Replaces placeholders with corresponding character AFTER processing is done.
+        $placeholders = array("&&058;", "&&035;", "&&061;", "&&123;", "&&125;", "&&126;", "&&010");
+        $characters   = array(":",     "#",      "=",      "{",      "}",      "~",      "\n"  );
+        $string = str_replace($placeholders, $characters, $string);
+        return $string;
+    }
+
+    protected function check_answer_count($min, $answers, $text) {
+        $countanswers = count($answers);
+        if ($countanswers < $min) {
+            $this->error(get_string('importminerror', 'qformat_gift'), $text);
+            return false;
+        }
+
+        return true;
+    }
+
+    protected function parse_text_with_format($text, $defaultformat = FORMAT_MOODLE) {
+        $result = array(
+            'text' => $text,
+            'format' => $defaultformat,
+            'files' => array(),
+        );
+        if (strpos($text, '[') === 0) {
+            $formatend = strpos($text, ']');
+            $result['format'] = $this->format_name_to_const(substr($text, 1, $formatend - 1));
+            if ($result['format'] == -1) {
+                $result['format'] = $defaultformat;
+            } else {
+                $result['text'] = substr($text, $formatend + 1);
+            }
+        }
+        $result['text'] = trim($this->escapedchar_post($result['text']));
+        return $result;
+    }
+
+    public function readquestion($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.
+
+        $question = $this->defaultquestion();
+        // Define replaced by simple assignment, stop redefine notices.
+        $giftanswerweightregex = '/^%\-*([0-9]{1,2})\.?([0-9]*)%/';
+
+        // Separate comments and implode.
+        $comments = '';
+        foreach ($lines as $key => $line) {
+            $line = trim($line);
+            if (substr($line, 0, 2) == '//') {
+                $comments .= $line . "\n";
+                $lines[$key] = ' ';
+            }
+        }
+        $text = trim(implode("\n", $lines));
+
+        if ($text == '') {
+            return false;
+        }
+
+        // Substitute escaped control characters with placeholders.
+        $text = $this->escapedchar_pre($text);
+
+        // Look for category modifier.
+        if (preg_match('~^\$CATEGORY:~', $text)) {
+            $newcategory = trim(substr($text, 10));
+
+            // Build fake question to contain category.
+            $question->qtype = 'category';
+            $question->category = $newcategory;
+            return $question;
+        }
+
+        // Question name parser.
+        if (substr($text, 0, 2) == '::') {
+            $text = substr($text, 2);
+
+            $namefinish = strpos($text, '::');
+            if ($namefinish === false) {
+                $question->name = false;
+                // Name will be assigned after processing question text below.
+            } else {
+                $questionname = substr($text, 0, $namefinish);
+                $question->name = $this->clean_question_name($this->escapedchar_post($questionname));
+                $text = trim(substr($text, $namefinish+2)); // Remove name from text.
+            }
+        } else {
+            $question->name = false;
+        }
+
+        // Find the answer section.
+        $answerstart = strpos($text, '{');
+        $answerfinish = strpos($text, '}');
+
+        $description = false;
+        if ($answerstart === false && $answerfinish === false) {
+            // No answer means it's a description.
+            $description = true;
+            $answertext = '';
+            $answerlength = 0;
+
+        } else if ($answerstart === false || $answerfinish === false) {
+            $this->error(get_string('braceerror', 'qformat_gift'), $text);
+            return false;
+
+        } else {
+            $answerlength = $answerfinish - $answerstart;
+            $answertext = trim(substr($text, $answerstart + 1, $answerlength - 1));
+        }
+
+        // Format the question text, without answer, inserting "_____" as necessary.
+        if ($description) {
+            $questiontext = $text;
+        } else if (substr($text, -1) == "}") {
+            // No blank line if answers follow question, outside of closing punctuation.
+            $questiontext = substr_replace($text, "", $answerstart, $answerlength + 1);
+        } else {
+            // Inserts blank line for missing word format.
+            $questiontext = substr_replace($text, "_____", $answerstart, $answerlength + 1);
+        }
+
+        // Look to see if there is any general feedback.
+        $gfseparator = strrpos($answertext, '####');
+        if ($gfseparator === false) {
+            $generalfeedback = '';
+        } else {
+            $generalfeedback = substr($answertext, $gfseparator + 4);
+            $answertext = trim(substr($answertext, 0, $gfseparator));
+        }
+
+        // Get questiontext format from questiontext.
+        $text = $this->parse_text_with_format($questiontext);
+        $question->questiontextformat = $text['format'];
+        $question->questiontext = $text['text'];
+
+        // Get generalfeedback format from questiontext.
+        $text = $this->parse_text_with_format($generalfeedback, $question->questiontextformat);
+        $question->generalfeedback = $text['text'];
+        $question->generalfeedbackformat = $text['format'];
+
+        // Set question name if not already set.
+        if ($question->name === false) {
+            $question->name = $this->create_default_question_name($question->questiontext, get_string('questionname', 'question'));
+        }
+
+        // Determine question type.
+        $question->qtype = null;
+
+        // Extract any idnumber and tags from the comments.
+        list($question->idnumber, $question->tags) = $this->extract_idnumber_and_tags_from_comment($comments);
+
+        // Give plugins first try.
+        // Plugins must promise not to intercept standard qtypes
+        // MDL-12346, this could be called from lesson mod which has its own base class =(.
+        if (method_exists($this, 'try_importing_using_qtypes')
+                && ($tryquestion = $this->try_importing_using_qtypes($lines, $question, $answertext))) {
+            return $tryquestion;
+        }
+
+        if ($description) {
+            $question->qtype = 'description';
+
+        } else if ($answertext == '') {
+            $question->qtype = 'essay';
+
+        } else if ($answertext[0] == '#') {
+            $question->qtype = 'numerical';
+
+        } else if (strpos($answertext, '~') !== false) {
+            // Only Multiplechoice questions contain tilde ~.
+            $question->qtype = 'multichoice';
+
+        } else if (strpos($answertext, '=')  !== false
+                && strpos($answertext, '->') !== false) {
+            // Only Matching contains both = and ->.
+            $question->qtype = 'match';
+
+        } else { // Either truefalse or shortanswer.
+
+            // Truefalse question check.
+            $truefalsecheck = $answertext;
+            if (strpos($answertext, '#') > 0) {
+                // Strip comments to check for TrueFalse question.
+                $truefalsecheck = trim(substr($answertext, 0, strpos($answertext, "#")));
+            }
+
+            $validtfanswers = array('T', 'TRUE', 'F', 'FALSE');
+            if (in_array($truefalsecheck, $validtfanswers)) {
+                $question->qtype = 'truefalse';
+
+            } else { // Must be shortanswer.
+                $question->qtype = 'shortanswer';
+            }
+        }
+
+        if (!isset($question->qtype)) {
+            $giftqtypenotset = get_string('giftqtypenotset', 'qformat_gift');
+            $this->error($giftqtypenotset, $text);
+            return false;
+        }
+
+        switch ($question->qtype) {
+            case 'description':
+                $question->defaultmark = 0;
+                $question->length = 0;
+                return $question;
+
+            case 'essay':
+                $question->responseformat = 'editor';
+                $question->responserequired = 1;
+                $question->responsefieldlines = 15;
+                $question->attachments = 0;
+                $question->attachmentsrequired = 0;
+                $question->graderinfo = array(
+                        'text' => '', 'format' => FORMAT_HTML, 'files' => array());
+                $question->responsetemplate = array(
+                        'text' => '', 'format' => FORMAT_HTML);
+                return $question;
+
+            case 'multichoice':
+                // "Temporary" solution to enable choice of answernumbering on GIFT import
+                // by respecting default set for multichoice questions (MDL-59447)
+                $question->answernumbering = get_config('qtype_multichoice', 'answernumbering');
+
+                if (strpos($answertext, "=") === false) {
+                    $question->single = 0; // Multiple answers are enabled if no single answer is 100% correct.
+                } else {
+                    $question->single = 1; // Only one answer allowed (the default).
+                }
+                $question = $this->add_blank_combined_feedback($question);
+
+                $answertext = str_replace("=", "~=", $answertext);
+                $answers = explode("~", $answertext);
+                if (isset($answers[0])) {
+                    $answers[0] = trim($answers[0]);
+                }
+                if (empty($answers[0])) {
+                    array_shift($answers);
+                }
+
+                $countanswers = count($answers);
+
+                if (!$this->check_answer_count(2, $answers, $text)) {
+                    return false;
+                }
+
+                foreach ($answers as $key => $answer) {
+                    $answer = trim($answer);
+
+                    // Determine answer weight.
+                    if ($answer[0] == '=') {
+                        $answerweight = 1;
+                        $answer = substr($answer, 1);
+
+                    } else if (preg_match($giftanswerweightregex, $answer)) {    // Check for properly formatted answer weight.
+                        $answerweight = $this->answerweightparser($answer);
+
+                    } else {     // Default, i.e., wrong anwer.
+                        $answerweight = 0;
+                    }
+                    list($question->answer[$key], $question->feedback[$key]) =
+                            $this->commentparser($answer, $question->questiontextformat);
+                    $question->fraction[$key] = $answerweight;
+                }  // End foreach answer.
+
+                return $question;
+
+            case 'match':
+                $question = $this->add_blank_combined_feedback($question);
+
+                $answers = explode('=', $answertext);
+                if (isset($answers[0])) {
+                    $answers[0] = trim($answers[0]);
+                }
+                if (empty($answers[0])) {
+                    array_shift($answers);
+                }
+
+                if (!$this->check_answer_count(2, $answers, $text)) {
+                    return false;
+                }
+
+                foreach ($answers as $key => $answer) {
+                    $answer = trim($answer);
+                    if (strpos($answer, "->") === false) {
+                        $this->error(get_string('giftmatchingformat', 'qformat_gift'), $answer);
+                        return false;
+                    }
+
+                    $marker = strpos($answer, '->');
+                    $question->subquestions[$key] = $this->parse_text_with_format(
+                            substr($answer, 0, $marker), $question->questiontextformat);
+                    $question->subanswers[$key] = trim($this->escapedchar_post(
+                            substr($answer, $marker + 2)));
+                }
+
+                return $question;
+
+            case 'truefalse':
+                list($answer, $wrongfeedback, $rightfeedback) =
+                        $this->split_truefalse_comment($answertext, $question->questiontextformat);
+
+                if ($answer['text'] == "T" || $answer['text'] == "TRUE") {
+                    $question->correctanswer = 1;
+                    $question->feedbacktrue = $rightfeedback;
+                    $question->feedbackfalse = $wrongfeedback;
+                } else {
+                    $question->correctanswer = 0;
+                    $question->feedbacktrue = $wrongfeedback;
+                    $question->feedbackfalse = $rightfeedback;
+                }
+
+                $question->penalty = 1;
+
+                return $question;
+
+            case 'shortanswer':
+                // Shortanswer question.
+                $answers = explode("=", $answertext);
+                if (isset($answers[0])) {
+                    $answers[0] = trim($answers[0]);
+                }
+                if (empty($answers[0])) {
+                    array_shift($answers);
+                }
+
+                if (!$this->check_answer_count(1, $answers, $text)) {
+                    return false;
+                }
+
+                foreach ($answers as $key => $answer) {
+                    $answer = trim($answer);
+
+                    // Answer weight.
+                    if (preg_match($giftanswerweightregex, $answer)) {    // Check for properly formatted answer weight.
+                        $answerweight = $this->answerweightparser($answer);
+                    } else {     // Default, i.e., full-credit anwer.
+                        $answerweight = 1;
+                    }
+
+                    list($answer, $question->feedback[$key]) = $this->commentparser(
+                            $answer, $question->questiontextformat);
+
+                    $question->answer[$key] = $answer['text'];
+                    $question->fraction[$key] = $answerweight;
+                }
+
+                return $question;
+
+            case 'numerical':
+                // Note similarities to ShortAnswer.
+                $answertext = substr($answertext, 1); // Remove leading "#".
+
+                // If there is feedback for a wrong answer, store it for now.
+                if (($pos = strpos($answertext, '~')) !== false) {
+                    $wrongfeedback = substr($answertext, $pos);
+                    $answertext = substr($answertext, 0, $pos);
+                } else {
+                    $wrongfeedback = '';
+                }
+
+                $answers = explode("=", $answertext);
+                if (isset($answers[0])) {
+                    $answers[0] = trim($answers[0]);
+                }
+                if (empty($answers[0])) {
+                    array_shift($answers);
+                }
+
+                if (count($answers) == 0) {
+                    // Invalid question.
+                    $giftnonumericalanswers = get_string('giftnonumericalanswers', 'qformat_gift');
+                    $this->error($giftnonumericalanswers, $text);
+                    return false;
+                }
+
+                foreach ($answers as $key => $answer) {
+                    $answer = trim($answer);
+
+                    // Answer weight.
+                    if (preg_match($giftanswerweightregex, $answer)) {    // Check for properly formatted answer weight.
+                        $answerweight = $this->answerweightparser($answer);
+                    } else {     // Default, i.e., full-credit anwer.
+                        $answerweight = 1;
+                    }
+
+                    list($answer, $question->feedback[$key]) = $this->commentparser(
+                            $answer, $question->questiontextformat);
+                    $question->fraction[$key] = $answerweight;
+                    $answer = $answer['text'];
+
+                    // Calculate Answer and Min/Max values.
+                    if (strpos($answer, "..") > 0) { // Optional [min]..[max] format.
+                        $marker = strpos($answer, "..");
+                        $max = trim(substr($answer, $marker + 2));
+                        $min = trim(substr($answer, 0, $marker));
+                        $ans = ($max + $min)/2;
+                        $tol = $max - $ans;
+                    } else if (strpos($answer, ':') > 0) { // Standard [answer]:[errormargin] format.
+                        $marker = strpos($answer, ':');
+                        $tol = trim(substr($answer, $marker+1));
+                        $ans = trim(substr($answer, 0, $marker));
+                    } else { // Only one valid answer (zero errormargin).
+                        $tol = 0;
+                        $ans = trim($answer);
+                    }
+
+                    if (!(is_numeric($ans) || $ans = '*') || !is_numeric($tol)) {
+                            $errornotnumbers = get_string('errornotnumbers');
+                            $this->error($errornotnumbers, $text);
+                        return false;
+                    }
+
+                    // Store results.
+                    $question->answer[$key] = $ans;
+                    $question->tolerance[$key] = $tol;
+                }
+
+                if ($wrongfeedback) {
+                    $key += 1;
+                    $question->fraction[$key] = 0;
+                    list($notused, $question->feedback[$key]) = $this->commentparser(
+                            $wrongfeedback, $question->questiontextformat);
+                    $question->answer[$key] = '*';
+                    $question->tolerance[$key] = '';
+                }
+
+                return $question;
+
+            default:
+                $this->error(get_string('giftnovalidquestion', 'qformat_gift'), $text);
+                return false;
+
+        }
+    }
+
+    protected function repchar($text, $notused = 0) {
+        // Escapes 'reserved' characters # = ~ {) :
+        // Removes new lines.
+        $reserved = array(  '\\',  '#', '=', '~', '{', '}', ':', "\n", "\r");
+        $escaped =  array('\\\\', '\#', '\=', '\~', '\{', '\}', '\:', '\n', '');
+
+        $newtext = str_replace($reserved, $escaped, $text);
+        return $newtext;
+    }
+
+    /**
+     * @param int $format one of the FORMAT_ constants.
+     * @return string the corresponding name.
+     */
+    protected function format_const_to_name($format) {
+        if ($format == FORMAT_MOODLE) {
+            return 'moodle';
+        } else if ($format == FORMAT_HTML) {
+            return 'html';
+        } else if ($format == FORMAT_PLAIN) {
+            return 'plain';
+        } else if ($format == FORMAT_MARKDOWN) {
+            return 'markdown';
+        } else {
+            return 'moodle';
+        }
+    }
+
+    /**
+     * @param int $format one of the FORMAT_ constants.
+     * @return string the corresponding name.
+     */
+    protected function format_name_to_const($format) {
+        if ($format == 'moodle') {
+            return FORMAT_MOODLE;
+        } else if ($format == 'html') {
+            return FORMAT_HTML;
+        } else if ($format == 'plain') {
+            return FORMAT_PLAIN;
+        } else if ($format == 'markdown') {
+            return FORMAT_MARKDOWN;
+        } else {
+            return -1;
+        }
+    }
+
+    /**
+     * Extract any tags or idnumber declared in the question comment.
+     *
+     * @param string $comment E.g. "// Line 1.\n//Line 2.\n".
+     * @return array with two elements. string $idnumber (or '') and string[] of tags.
+     */
+    public function extract_idnumber_and_tags_from_comment(string $comment): array {
+
+        // Find the idnumber, if any. There should not be more than one, but if so, we just find the first.
+        $idnumber = '';
+        if (preg_match('~
+                # Start of id token.
+                \[id:
+
+                # Any number of (non-control) characters, with any ] escaped.
+                # This is the bit we want so capture it.
+                (
+                    (?:\\\\]|[^][:cntrl:]])+
+                )
+
+                # End of id token.
+                ]
+                ~x', $comment, $match)) {
+            $idnumber = str_replace('\]', ']', trim($match[1]));
+        }
+
+        // Find any tags.
+        $tags = [];
+        if (preg_match_all('~
+                # Start of tag token.
+                \[tag:
+
+                # Any number of allowed characters (see PARAM_TAG), with any ] escaped.
+                # This is the bit we want so capture it.
+                (
+                    (?:\\\\]|[^]<>`[:cntrl:]]|)+
+                )
+
+                # End of tag token.
+                ]
+                ~x', $comment, $matches)) {
+            foreach ($matches[1] as $rawtag) {
+                $tags[] = str_replace('\]', ']', trim($rawtag));
+            }
+        }
+
+        return [$idnumber, $tags];
+    }
+
+    public function write_name($name) {
+        return '::' . $this->repchar($name) . '::';
+    }
+
+    public function write_questiontext($text, $format, $defaultformat = FORMAT_MOODLE) {
+        $output = '';
+        if ($text != '' && $format != $defaultformat) {
+            $output .= '[' . $this->format_const_to_name($format) . ']';
+        }
+        $output .= $this->repchar($text, $format);
+        return $output;
+    }
+
+    /**
+     * Outputs the general feedback for the question, if any. This needs to be the
+     * last thing before the }.
+     * @param object $question the question data.
+     * @param string $indent to put before the general feedback. Defaults to a tab.
+     *      If this is not blank, a newline is added after the line.
+     */
+    public function write_general_feedback($question, $indent = "\t") {
+        $generalfeedback = $this->write_questiontext($question->generalfeedback,
+                $question->generalfeedbackformat, $question->questiontextformat);
+
+        if ($generalfeedback) {
+            $generalfeedback = '####' . $generalfeedback;
+            if ($indent) {
+                $generalfeedback = $indent . $generalfeedback . "\n";
+            }
+        }
+
+        return $generalfeedback;
+    }
+
+    public function writequestion($question) {
+
+        // Start with a comment.
+        $expout = "// question: {$question->id}  name: {$question->name}\n";
+        $expout .= $this->write_idnumber_and_tags($question);
+
+        // Output depends on question type.
+        switch($question->qtype) {
+
+            case 'category':
+                // Not a real question, used to insert category switch.
+                $expout .= "\$CATEGORY: $question->category\n";
+                break;
+
+            case 'description':
+                $expout .= $this->write_name($question->name);
+                $expout .= $this->write_questiontext($question->questiontext, $question->questiontextformat);
+                break;
+
+            case 'essay':
+                $expout .= $this->write_name($question->name);
+                $expout .= $this->write_questiontext($question->questiontext, $question->questiontextformat);
+                $expout .= "{";
+                $expout .= $this->write_general_feedback($question, '');
+                $expout .= "}\n";
+                break;
+
+            case 'truefalse':
+                $trueanswer = $question->options->answers[$question->options->trueanswer];
+                $falseanswer = $question->options->answers[$question->options->falseanswer];
+                if ($trueanswer->fraction == 1) {
+                    $answertext = 'TRUE';
+                    $rightfeedback = $this->write_questiontext($trueanswer->feedback,
+                            $trueanswer->feedbackformat, $question->questiontextformat);
+                    $wrongfeedback = $this->write_questiontext($falseanswer->feedback,
+                            $falseanswer->feedbackformat, $question->questiontextformat);
+                } else {
+                    $answertext = 'FALSE';
+                    $rightfeedback = $this->write_questiontext($falseanswer->feedback,
+                            $falseanswer->feedbackformat, $question->questiontextformat);
+                    $wrongfeedback = $this->write_questiontext($trueanswer->feedback,
+                            $trueanswer->feedbackformat, $question->questiontextformat);
+                }
+
+                $expout .= $this->write_name($question->name);
+                $expout .= $this->write_questiontext($question->questiontext, $question->questiontextformat);
+                $expout .= '{' . $this->repchar($answertext);
+                if ($wrongfeedback) {
+                    $expout .= '#' . $wrongfeedback;
+                } else if ($rightfeedback) {
+                    $expout .= '#';
+                }
+                if ($rightfeedback) {
+                    $expout .= '#' . $rightfeedback;
+                }
+                $expout .= $this->write_general_feedback($question, '');
+                $expout .= "}\n";
+                break;
+
+            case 'multichoice':
+                $expout .= $this->write_name($question->name);
+                $expout .= $this->write_questiontext($question->questiontext, $question->questiontextformat);
+                $expout .= "{\n";
+                foreach ($question->options->answers as $answer) {
+                    if ($answer->fraction == 1 && $question->options->single) {
+                        $answertext = '=';
+                    } else if ($answer->fraction == 0) {
+                        $answertext = '~';
+                    } else {
+                        $weight = $answer->fraction * 100;
+                        $answertext = '~%' . $weight . '%';
+                    }
+                    $expout .= "\t" . $answertext . $this->write_questiontext($answer->answer,
+                                $answer->answerformat, $question->questiontextformat);
+                    if ($answer->feedback != '') {
+                        $expout .= '#' . $this->write_questiontext($answer->feedback,
+                                $answer->feedbackformat, $question->questiontextformat);
+                    }
+                    $expout .= "\n";
+                }
+                $expout .= $this->write_general_feedback($question);
+                $expout .= "}\n";
+                break;
+
+            case 'shortanswer':
+                $expout .= $this->write_name($question->name);
+                $expout .= $this->write_questiontext($question->questiontext, $question->questiontextformat);
+                $expout .= "{\n";
+                foreach ($question->options->answers as $answer) {
+                    $weight = 100 * $answer->fraction;
+                    $expout .= "\t=%" . $weight . '%' . $this->repchar($answer->answer) .
+                            '#' . $this->write_questiontext($answer->feedback,
+                                $answer->feedbackformat, $question->questiontextformat) . "\n";
+                }
+                $expout .= $this->write_general_feedback($question);
+                $expout .= "}\n";
+                break;
+
+            case 'numerical':
+                $expout .= $this->write_name($question->name);
+                $expout .= $this->write_questiontext($question->questiontext, $question->questiontextformat);
+                $expout .= "{#\n";
+                foreach ($question->options->answers as $answer) {
+                    if ($answer->answer != '' && $answer->answer != '*') {
+                        $weight = 100 * $answer->fraction;
+                        $expout .= "\t=%" . $weight . '%' . $answer->answer . ':' .
+                                (float)$answer->tolerance . '#' . $this->write_questiontext($answer->feedback,
+                                $answer->feedbackformat, $question->questiontextformat) . "\n";
+                    } else {
+                        $expout .= "\t~#" . $this->write_questiontext($answer->feedback,
+                                $answer->feedbackformat, $question->questiontextformat) . "\n";
+                    }
+                }
+                $expout .= $this->write_general_feedback($question);
+                $expout .= "}\n";
+                break;
+
+            case 'match':
+                $expout .= $this->write_name($question->name);
+                $expout .= $this->write_questiontext($question->questiontext, $question->questiontextformat);
+                $expout .= "{\n";
+                foreach ($question->options->subquestions as $subquestion) {
+                    $expout .= "\t=" . $this->write_questiontext($subquestion->questiontext,
+                            $subquestion->questiontextformat, $question->questiontextformat) .
+                            ' -> ' . $this->repchar($subquestion->answertext) . "\n";
+                }
+                $expout .= $this->write_general_feedback($question);
+                $expout .= "}\n";
+                break;
+
+            default:
+                // Check for plugins.
+                if ($out = $this->try_exporting_using_qtypes($question->qtype, $question)) {
+                    $expout .= $out;
+                }
+        }
+
+        // Add empty line to delimit questions.
+        $expout .= "\n";
+        return $expout;
+    }
+
+    /**
+     * Prepare any question idnumber or tags for export.
+     *
+     * @param stdClass $questiondata the question data we are exporting.
+     * @return string a string that can be written as a line in the GIFT file,
+     *      e.g. "// [id:myid] [tag:some-tag]\n". Will be '' if none.
+     */
+    public function write_idnumber_and_tags(stdClass $questiondata): string {
+        if ($questiondata->qtype == 'category') {
+            return '';
+        }
+
+        $bits = [];
+
+        if (isset($questiondata->idnumber) && $questiondata->idnumber !== '') {
+            $bits[] = '[id:' . str_replace(']', '\]', $questiondata->idnumber) . ']';
+        }
+
+        // Write the question tags.
+        if (core_tag_tag::is_enabled('core_question', 'question')) {
+            $tagobjects = core_tag_tag::get_item_tags('core_question', 'question', $questiondata->id);
+
+            if (!empty($tagobjects)) {
+                $context = context::instance_by_id($questiondata->contextid);
+                $sortedtagobjects = question_sort_tags($tagobjects, $context, [$this->course]);
+
+                // Currently we ignore course tags. This should probably be fixed in future.
+
+                if (!empty($sortedtagobjects->tags)) {
+                    foreach ($sortedtagobjects->tags as $tag) {
+                        $bits[] = '[tag:' . str_replace(']', '\]', $tag) . ']';
+                    }
+                }
+            }
+        }
+
+        if (!$bits) {
+            return '';
+        }
+
+        return '// ' . implode(' ', $bits) . "\n";
+    }
+}

question/format/gift/lang/en/qformat_gift.php

@@ -0,0 +1,37 @@
+<?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/>.
+
+/**
+ * Strings for component 'qformat_gift', language 'en', branch 'MOODLE_20_STABLE'
+ *
+ * @package    qformat_gift
+ * @copyright  1999 onwards Martin Dougiamas  {@link http://moodle.com}
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+$string['braceerror'] = 'Could not find {...} around answers';
+$string['giftleftbraceerror'] = 'Could not find a {';
+$string['giftmatchingformat'] = 'Matching question answers are improperly formatted';
+$string['giftnonumericalanswers'] = 'No answers found for numerical question';
+$string['giftnovalidquestion'] = 'No valid question found';
+$string['giftqtypenotset'] = 'Question type is not set';
+$string['giftrightbraceerror'] = 'Could not find a }';
+$string['importminerror'] = 'There is an error in the question. There are not enough answers for this question type';
+$string['nohandler'] = 'No handler for question type {$a}';
+$string['pluginname'] = 'GIFT format';
+$string['pluginname_help'] = 'GIFT format enables multiple choice, true/false, short answer, matching, missing word, numerical and essay questions to be imported or exported via text file.';
+$string['pluginname_link'] = 'qformat/gift';
+$string['privacy:metadata'] = 'The GIFT question format plugin does not store any personal data.';

question/format/gift/tests/behat/import_export.feature

@@ -0,0 +1,54 @@
+@qformat @qformat_gift
+Feature: Test importing questions from GIFT format.
+  In order to reuse questions
+  As an teacher
+  I need to be able to import them in GIFT format.
+
+  Background:
+    Given the following "courses" exist:
+      | fullname | shortname | format |
+      | Course 1 | C1        | topics |
+    And the following "users" exist:
+      | username | firstname |
+      | teacher  | Teacher   |
+    And the following "course enrolments" exist:
+      | user    | course | role           |
+      | teacher | C1     | editingteacher |
+    And I am on the "Course 1" "core_question > course question import" page logged in as "teacher"
+
+  @javascript @_file_upload
+  Scenario: import some GIFT questions
+    When I set the field "id_format_gift" to "1"
+    And I upload "question/format/gift/tests/fixtures/questions.gift.txt" file to "Import" filemanager
+    And I press "id_submitbutton"
+    Then I should see "Parsing questions from import file."
+    And I should see "Importing 9 questions from file"
+    And I should see "What's between orange and green in the spectrum?"
+    When I press "Continue"
+    Then I should see "colours"
+
+    # Now export again.
+    And I am on the "Course 1" "core_question > course question export" page
+    And I set the field "id_format_gift" to "1"
+    And I press "Export questions to file"
+    And following "click here" should download a file that:
+      | Has mimetype  | text/plain                                       |
+      | Contains text | What's between orange and green in the spectrum? |
+
+  @javascript @_file_upload
+  Scenario: import a GIFT file which specifies the category
+    When I set the field "id_format_gift" to "1"
+    And I upload "question/format/gift/tests/fixtures/questions_in_category.gift.txt" file to "Import" filemanager
+    And I press "id_submitbutton"
+    Then I should see "Parsing questions from import file."
+    And I should see "Importing 4 questions from file"
+    And I should see "Match the activity to the description."
+    When I press "Continue"
+    Then I should see "Moodle activities"
+
+  @javascript @_file_upload
+  Scenario: import some GIFT questions with unsupported encoding
+    When I set the field "id_format_gift" to "1"
+    And I upload "question/format/gift/tests/fixtures/questions_encoding_windows-1252.gift.txt" file to "Import" filemanager
+    And I press "id_submitbutton"
+    Then I should see "The file you selected does not use UTF-8 character encoding. GIFT format files must use UTF-8."

question/format/gift/tests/fixtures/questions.gift.txt

@@ -0,0 +1,49 @@
+// essay
+::Q8:: How are you? {}
+
+// question: 2  name: Moodle activities
+::Moodle activities::[html]Match the <b>activity</b> to the description.{
+    =[html]An activity supporting asynchronous discussions. -> Forum
+    =[moodle]A teacher asks a question and specifies a choice of multiple responses. -> Choice
+    =[plain]A bank of record entries which participants can add to. -> Database
+    =[markdown]A collection of web pages that anyone can add to or edit. -> Wiki
+    = -> Chat
+}
+
+// multiple choice with specified feedback for right and wrong answers
+::Q2:: What's between orange and green in the spectrum?
+{
+    =yellow # right; good!
+    ~red # [html]wrong, it's yellow
+    ~[plain]blue # wrong, it's yellow
+}
+
+// multiple choice, multiple response with specified feedback for right and wrong answers
+::colours:: What's between orange and green in the spectrum?
+{
+    ~%50%yellow # right; good!
+    ~%-100%red # [html]wrong
+    ~%50%off-beige # right; good!
+    ~%-100%[plain]blue # wrong
+}
+
+// math range question
+::Q5:: What is a number from 1 to 5? {#3:2~#Completely wrong}";
+
+// question: 666  name: Shortanswer
+::Shortanswer::Which is the best animal?{
+    =Frog#Good!
+    =%50%Cat#What is it with Moodlers and cats?
+    =%0%*#Completely wrong
+}
+
+// true/false, with general feedback
+::Q1:: 42 is the Absolute Answer to everything.{
+FALSE#42 is the Ultimate Answer.#You gave the right answer.
+####This is, of course, a Hitchiker's Guide to the Galaxy reference.}";
+
+// name 0-11
+::2-08 TSL::TSL is blablabla.{T}
+
+// name 0-11
+::2-08 TSL::TSL is blablabla.{TRUE}

question/format/gift/tests/fixtures/questions_encoding_windows-1252.gift.txt

@@ -0,0 +1,18 @@
+// question: 0  name: Switch category to $course$/top/Default for LTTEST
+$CATEGORY: $course$/top/Default for LTTEST
+
+
+// question: 19756780  name: asdf
+::asdf::[html]<p>asdf<br></p>{}
+
+
+// question: 19756810  name: test daniel
+::test daniel::[html]<p>asdfasdf</p>{}
+
+
+// question: 19756750  name: asdf
+::asdf::[html]<p>asdf<br></p>{
+	=<p>aödf<br></p> -> asdf
+	=<p>asdf<br></p> -> asdf
+	=<p>asdf<br></p> -> asdf
+}

question/format/gift/tests/fixtures/questions_in_category.gift.txt

@@ -0,0 +1,27 @@
+// question: 0  name: switch category to $course$/Default for New Features
+$CATEGORY: $course$/Default for New Features
+
+// question: 44  name: Moodle activities
+::Moodle activities::[html]Match the activity to the description.{
+	=An activity supporting asynchronous discussions. -> Forum
+	=A teacher asks a question and specifies a choice of multiple responses. -> Choice
+	=A bank of record entries which participants can add to. -> Database
+	=A collection of web pages that anyone can add to or edit. -> Wiki
+	= -> Chat
+}
+
+// question: 43  name: Greeting
+::Greeting::[html]<a href\="http\://demo.moodle.net/file.php/5/media/bonjour.mp3">Listen to this greeting\:</a><br /><br />What language is being spoken?{
+	~English#Sorry, listen again.
+	=French#Yes, well done!
+	~German#Sorry, listen again.
+	~Spanish#Sorry, listen again.
+}
+
+// question: 46  name: Moodle user
+::Moodle user::[html]Anyone who uses Moodle is a ...{
+	=%100%Moodler#
+}
+
+// question: 45  name: Moodle acronym
+::Moodle acronym::[html]Moodle is an acronym for <span style\="font-style\: italic;">Modular Object-Oriented Dynamic Learning Environment</span>.{TRUE}

question/format/gift/version.php

@@ -0,0 +1,32 @@
+<?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/>.
+
+/**
+ * Version information for the calculated question type.
+ *
+ * @package    qformat_gift
+ * @copyright  2011 The Open University
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+$plugin->component = 'qformat_gift';
+$plugin->version   = 2024042200;
+
+$plugin->requires  = 2024041600;
+
+$plugin->maturity  = MATURITY_STABLE;