MDL-61363 question: add course context tagging

lang/en/question.php

@@ -391,6 +391,7 @@ $string['questionbehavioursdisabledexplained'] = 'Enter a comma separated list o
 $string['questionbehavioursorder'] = 'Question behaviours order';
 $string['questionbehavioursorderexplained'] = 'Enter a comma separated list of behaviours in the order you want them to appear in dropdown menu';
 $string['questionidmismatch'] = 'Question ids mismatch';
+$string['questionformtagheader'] = '{$a} tags';
 $string['questionname'] = 'Question name';
 $string['questionnamecopy'] = '{$a} (copy)';
 $string['questionpreviewdefaults'] = 'Question preview defaults';

lib/questionlib.php

@@ -770,9 +770,11 @@ function question_load_questions($questionids, $extrafields = '', $join = '') {
  * Private function to factor common code out of get_question_options().
  *
  * @param object $question the question to tidy.
- * @param boolean $loadtags load the question tags from the tags table. Optional, default false.
+ * @param stdClass $category The question_categories record for the given $question.
+ * @param stdClass[]|null $tagobjects The tags for the given $question.
+ * @param stdClass[]|null $filtercourses The courses to filter the course tags by.
  */
-function _tidy_question($question, $loadtags = false) {
+function _tidy_question($question, $category, array $tagobjects = null, array $filtercourses = null) {
     global $CFG;
 
     // Load question-type specific fields.
@@ -790,8 +792,76 @@ function _tidy_question($question, $loadtags = false) {
         unset($question->_partiallyloaded);
     }
 
-    if ($loadtags && core_tag_tag::is_enabled('core_question', 'question')) {
-        $question->tags = core_tag_tag::get_item_tags_array('core_question', 'question', $question->id);
+    $question->categoryobject = $category;
+
+    if (!is_null($tagobjects)) {
+        $categorycontext = context::instance_by_id($category->contextid);
+
+        // Questions can have two sets of tag instances. One set at the
+        // course context level and another at the context the question
+        // belongs to (e.g. course category, system etc).
+        $question->coursetagobjects = [];
+        $question->coursetags = [];
+        $question->tagobjects = [];
+        $question->tags = [];
+        $taginstanceidstonormalise = [];
+        $filtercoursecontextids = [];
+        $hasfiltercourses = !empty($filtercourses);
+
+        if ($hasfiltercourses) {
+            // If we're being asked to filter the course tags by a set of courses
+            // then get the context ids to filter below.
+            $filtercoursecontextids = array_map(function($course) {
+                $coursecontext = context_course::instance($course->id);
+                return $coursecontext->id;
+            }, $filtercourses);
+        }
+
+        foreach ($tagobjects as $tagobject) {
+            $tagcontextid = $tagobject->taginstancecontextid;
+            $tagcontext = context::instance_by_id($tagcontextid);
+            $tagcoursecontext = $tagcontext->get_course_context(false);
+            // This is a course tag if the tag context is a course context which
+            // doesn't match the question's context. Any tag in the question context
+            // is not considered a course tag, it belongs to the question.
+            $iscoursetag = $tagcoursecontext
+                && $tagcontext->id == $tagcoursecontext->id
+                && $tagcontext->id != $categorycontext->id;
+
+            if ($iscoursetag) {
+                // Any tag instance in a course context level is considered a course tag.
+                if (!$hasfiltercourses || in_array($tagcontextid, $filtercoursecontextids)) {
+                    // Add the tag to the list of course tags if we aren't being
+                    // asked to filter or if this tag is in the list of courses
+                    // we're being asked to filter by.
+                    $question->coursetagobjects[] = $tagobject;
+                    $question->coursetags[$tagobject->id] = $tagobject->get_display_name();
+                }
+            } else {
+                // All non course context level tag instances or tags in the question
+                // context belong to the context that the question was created in.
+                $question->tagobjects[] = $tagobject;
+                $question->tags[$tagobject->id] = $tagobject->get_display_name();
+
+                // Due to legacy tag implementations that don't force the recording
+                // of a context id, some tag instances may have context ids that don't
+                // match either a course context or the question context. In this case
+                // we should take the opportunity to fix up the data and set the correct
+                // context id.
+                if ($tagcontext->id != $categorycontext->id) {
+                    $taginstanceidstonormalise[] = $tagobject->taginstanceid;
+                    // Update the object properties to reflect the DB update that will
+                    // happen below.
+                    $tagobject->taginstancecontextid = $categorycontext->id;
+                }
+            }
+        }
+
+        if (!empty($taginstanceidstonormalise)) {
+            // If we found any tag instances with incorrect context id data then we can
+            // correct those values now by setting them to the question context id.
+            core_tag_tag::change_instances_context($taginstanceidstonormalise, $categorycontext);
+        }
     }
 }
 
@@ -804,17 +874,47 @@ function _tidy_question($question, $loadtags = false) {
  *
  * @param mixed $questions Either an array of question objects to be updated
  *         or just a single question object
- * @param boolean $loadtags load the question tags from the tags table. Optional, default false.
+ * @param bool $loadtags load the question tags from the tags table. Optional, default false.
+ * @param stdClass[] $filtercourses The courses to filter the course tags by.
  * @return bool Indicates success or failure.
  */
-function get_question_options(&$questions, $loadtags = false) {
-    if (is_array($questions)) { // deal with an array of questions
-        foreach ($questions as $i => $notused) {
-            _tidy_question($questions[$i], $loadtags);
+function get_question_options(&$questions, $loadtags = false, $filtercourses = null) {
+    global $DB;
+
+    $questionlist = is_array($questions) ? $questions : [$questions];
+    $categoryids = [];
+    $questionids = [];
+
+    if (empty($questionlist)) {
+        return true;
+    }
+
+    foreach ($questionlist as $question) {
+        $questionids[] = $question->id;
+
+        if (!in_array($question->category, $categoryids)) {
+            $categoryids[] = $question->category;
+        }
+    }
+
+    $categories = $DB->get_records_list('question_categories', 'id', $categoryids);
+
+    if ($loadtags && core_tag_tag::is_enabled('core_question', 'question')) {
+        $tagobjectsbyquestion = core_tag_tag::get_items_tags('core_question', 'question', $questionids);
+    } else {
+        $tagobjectsbyquestion = null;
+    }
+
+    foreach ($questionlist as $question) {
+        if (is_null($tagobjectsbyquestion)) {
+            $tagobjects = null;
+        } else {
+            $tagobjects = $tagobjectsbyquestion[$question->id];
         }
-    } else { // deal with single question
-        _tidy_question($questions, $loadtags);
+
+        _tidy_question($question, $categories[$question->category], $tagobjects, $filtercourses);
     }
+
     return true;
 }
 

question/question.php

@@ -120,7 +120,10 @@ if ($id) {
     if (!$question = $DB->get_record('question', array('id' => $id))) {
         print_error('questiondoesnotexist', 'question', $returnurl);
     }
-    get_question_options($question, true);
+    // We can use $COURSE here because it's been initialised as part of the
+    // require_login above. Passing it as the third parameter tells the function
+    // to filter the course tags by that course.
+    get_question_options($question, true, [$COURSE]);
 
 } else if ($categoryid && $qtype) { // only for creating new questions
     $question = new stdClass();
@@ -146,9 +149,13 @@ if ($id) {
 
 $qtypeobj = question_bank::get_qtype($question->qtype);
 
-// Validate the question category.
-if (!$category = $DB->get_record('question_categories', array('id' => $question->category))) {
-    print_error('categorydoesnotexist', 'question', $returnurl);
+if (isset($question->categoryobject)) {
+    $category = $question->categoryobject;
+} else {
+    // Validate the question category.
+    if (!$category = $DB->get_record('question_categories', array('id' => $question->category))) {
+        print_error('categorydoesnotexist', 'question', $returnurl);
+    }
 }
 
 // Check permissions
@@ -261,10 +268,18 @@ if ($mform->is_cancelled()) {
             print_error('nopermissions', '', '', 'edit');
         }
     }
+
     $question = $qtypeobj->save_question($question, $fromform);
     if (isset($fromform->tags)) {
+        // If we have any question context level tags then set those tags now.
+        core_tag_tag::set_item_tags('core_question', 'question', $question->id,
+                context::instance_by_id($contextid), $fromform->tags, 0);
+    }
+
+    if (isset($fromform->coursetags)) {
+        // If we have and course context level tags then set those now.
         core_tag_tag::set_item_tags('core_question', 'question', $question->id,
-                context::instance_by_id($contextid), $fromform->tags);
+                context_course::instance($fromform->courseid), $fromform->coursetags, 0);
     }
 
     // Purge this question from the cache.

question/type/edit_question_form.php

@@ -202,13 +202,7 @@ abstract class question_edit_form extends question_wizard_form {
         $this->definition_inner($mform);
 
         if (core_tag_tag::is_enabled('core_question', 'question')) {
-            $mform->addElement('header', 'tagsheader', get_string('tags'));
-            $mform->addElement('tags', 'tags', get_string('tags'),
-                array('itemtype' => 'question', 'component' => 'core_question'));
-
-            if (!question_has_capability_on($this->question, 'tag')) {
-                $mform->hardFreeze('tags');
-            }
+            $this->add_tag_fields($mform);
         }
 
         if (!empty($this->question->id)) {
@@ -309,6 +303,53 @@ abstract class question_edit_form extends question_wizard_form {
         return $repeated;
     }
 
+    /**
+     * Add the tag and course tag fields to the mform.
+     *
+     * If the form is being built in a course context then add the field
+     * for course tags.
+     *
+     * If the question category doesn't belong to a course context or we
+     * aren't editing in a course context then add the tags element to allow
+     * tags to be added to the question category context.
+     *
+     * @param object $mform The form being built
+     */
+    protected function add_tag_fields($mform) {
+        $hastagcapability = question_has_capability_on($this->question, 'tag');
+        // Is the question category in a course context?
+        $qcontext = $this->categorycontext;
+        $qcoursecontext = $qcontext->get_course_context(false);
+        $iscourseoractivityquestion = !empty($qcoursecontext);
+        // Is the current context we're editing in a course context?
+        $editingcontext = $this->contexts->lowest();
+        $editingcoursecontext = $editingcontext->get_course_context(false);
+        $iseditingcontextcourseoractivity = !empty($editingcoursecontext);
+
+        $mform->addElement('header', 'tagsheader', get_string('tags'));
+        $mform->addElement('tags', 'tags', get_string('tags'),
+                array('itemtype' => 'question', 'component' => 'core_question'));
+
+        if (!$hastagcapability) {
+            $mform->hardFreeze('tags');
+        }
+
+        if ($iseditingcontextcourseoractivity && !$iscourseoractivityquestion) {
+            // If the question is being edited in a course or activity context
+            // and the question isn't a course or activity level question then
+            // allow course tags to be added to the course.
+            $coursetagheader = get_string('questionformtagheader', 'core_question',
+                $editingcoursecontext->get_context_name(true));
+            $mform->addElement('header', 'coursetagsheader', $coursetagheader);
+            $mform->addElement('tags', 'coursetags', get_string('tags'),
+                    array('itemtype' => 'question', 'component' => 'core_question'));
+
+            if (!$hastagcapability) {
+                $mform->hardFreeze('coursetags');
+            }
+        }
+    }
+
     /**
      * Add a set of form fields, obtained from get_per_answer_fields, to the form,
      * one for each existing answer, with some blanks for some new ones.