MDL-61363 tag: allow tagging in different context to item

CengageEng · Mar 7, 2018 · 5436b0e · 5436b0e
1 parent 8376557
commit 5436b0e
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Showing 6 changed files with 122 additions and 9 deletions.
diff --git a/lib/db/install.xml b/lib/db/install.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<XMLDB PATH="lib/db" VERSION="20171222" COMMENT="XMLDB file for core Moodle tables"
+<XMLDB PATH="lib/db" VERSION="20180222" COMMENT="XMLDB file for core Moodle tables"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="../../lib/xmldb/xmldb.xsd"
 >
@@ -2019,6 +2019,7 @@
         <FIELD NAME="callback" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false"/>
         <FIELD NAME="callbackfile" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false"/>
         <FIELD NAME="showstandard" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
+        <FIELD NAME="multiplecontexts" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="Whether the tag area allows tag instances to be created in multiple contexts."/>
       </FIELDS>
       <KEYS>
         <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
@@ -2081,7 +2082,7 @@
         <KEY NAME="contextid" TYPE="foreign" FIELDS="contextid" REFTABLE="context" REFFIELDS="id"/>
       </KEYS>
       <INDEXES>
-        <INDEX NAME="taggeditem" UNIQUE="true" FIELDS="component, itemtype, itemid, tiuserid, tagid"/>
+        <INDEX NAME="taggeditem" UNIQUE="true" FIELDS="component, itemtype, itemid, contextid, tiuserid, tagid"/>
         <INDEX NAME="taglookup" UNIQUE="false" FIELDS="itemtype, component, tagid, contextid"/>
       </INDEXES>
     </TABLE>

diff --git a/lib/db/tag.php b/lib/db/tag.php
@@ -69,6 +69,7 @@
     array(
         'itemtype' => 'question', // Questions.
         'component' => 'core_question',
+        'multiplecontexts' => true,
     ),
     array(
         'itemtype' => 'post', // Blog posts.

diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
@@ -1974,13 +1974,51 @@ function xmldb_main_upgrade($oldversion) {
     }
 
     if ($oldversion < 2018022800.01) {
-
         // Fix old block configurations that use the deprecated (and now removed) object class.
         upgrade_fix_block_instance_configuration();
 
         // Main savepoint reached.
         upgrade_main_savepoint(true, 2018022800.01);
     }
 
+    if ($oldversion < 2018022800.02) {
+        // Define index taggeditem (unique) to be dropped form tag_instance.
+        $table = new xmldb_table('tag_instance');
+        $index = new xmldb_index('taggeditem', XMLDB_INDEX_UNIQUE, array('component',
+            'itemtype', 'itemid', 'tiuserid', 'tagid'));
+
+        // Conditionally launch drop index taggeditem.
+        if ($dbman->index_exists($table, $index)) {
+            $dbman->drop_index($table, $index);
+        }
+
+        $index = new xmldb_index('taggeditem', XMLDB_INDEX_UNIQUE, array('component',
+            'itemtype', 'itemid', 'contextid', 'tiuserid', 'tagid'));
+
+        // Conditionally launch add index taggeditem.
+        if (!$dbman->index_exists($table, $index)) {
+            $dbman->add_index($table, $index);
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2018022800.02);
+    }
+
+    if ($oldversion < 2018022800.03) {
+
+        // Define field multiplecontexts to be added to tag_area.
+        $table = new xmldb_table('tag_area');
+        $field = new xmldb_field('multiplecontexts', XMLDB_TYPE_INTEGER, '1', null,
+            XMLDB_NOTNULL, null, '0', 'showstandard');
+
+        // Conditionally launch add field multiplecontexts.
+        if (!$dbman->field_exists($table, $field)) {
+            $dbman->add_field($table, $field);
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2018022800.03);
+    }
+
     return true;
 }
diff --git a/tag/classes/area.php b/tag/classes/area.php
@@ -122,6 +122,32 @@ public static function is_enabled($component, $itemtype) {
         return null;
     }
 
+    /**
+     * Checks if the tag area allows items to be tagged in multiple different contexts.
+     *
+     * If true then it indicates that not all tag instance contexts must match the
+     * context of the item they are tagging. If false then all tag instance should
+     * match the context of the item they are tagging.
+     *
+     * Example use case for multi-context tagging:
+     * A question that exists in a course category context may be used by multiple
+     * child courses. The question tag area can allow tag instances to be created in
+     * multiple contexts which allows the tag API to tag the question at the course
+     * category context and then seperately in each of the child course contexts.
+     *
+     * @param string $component component responsible for tagging
+     * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.
+     * @return bool
+     */
+    public static function allows_tagging_in_multiple_contexts($component, $itemtype) {
+        $itemtypes = self::get_areas();
+        if (isset($itemtypes[$itemtype][$component])) {
+            $config = $itemtypes[$itemtype][$component];
+            return isset($config->multiplecontexts) ? $config->multiplecontexts : false;
+        }
+        return false;
+    }
+
     /**
      * Returns the id of the tag collection that should be used for storing tags of this itemtype
      *
@@ -217,7 +243,8 @@ protected static function create($record) {
             'tagcollid' => $record->tagcollid,
             'callback' => $record->callback,
             'callbackfile' => $record->callbackfile,
-            'showstandard' => isset($record->showstandard) ? $record->showstandard : core_tag_tag::BOTH_STANDARD_AND_NOT));
+            'showstandard' => isset($record->showstandard) ? $record->showstandard : core_tag_tag::BOTH_STANDARD_AND_NOT,
+            'multiplecontexts' => isset($record->multiplecontexts) ? $record->multiplecontexts : 0));
 
         // Reset cache.
         cache::make('core', 'tags')->delete('tag_area');
@@ -233,7 +260,8 @@ public static function update($existing, $data) {
         global $DB;
         $data = array_intersect_key((array)$data,
                 array('enabled' => 1, 'tagcollid' => 1,
-                    'callback' => 1, 'callbackfile' => 1, 'showstandard' => 1));
+                    'callback' => 1, 'callbackfile' => 1, 'showstandard' => 1,
+                    'multiplecontexts' => 1));
         foreach ($data as $key => $value) {
             if ($existing->$key == $value) {
                 unset($data[$key]);
@@ -310,6 +338,9 @@ public static function reset_definitions_for_component($componentname) {
                 if (!isset($record->callbackfile)) {
                     $record->callbackfile = null;
                 }
+                if (!isset($record->multiplecontexts)) {
+                    $record->multiplecontexts = false;
+                }
                 $itemtypes[$record->itemtype . ':' . $record->component] = $record;
             }
         }

diff --git a/tag/classes/tag.php b/tag/classes/tag.php
@@ -602,7 +602,7 @@ protected function add_instance($component, $itemtype, $itemid, context $context
         global $DB;
         $this->ensure_fields_exist(array('name', 'rawname'), 'add_instance');
 
-        $taginstance = new StdClass;
+        $taginstance = new stdClass;
         $taginstance->tagid        = $this->id;
         $taginstance->component    = $component ? $component : '';
         $taginstance->itemid       = $itemid;
@@ -773,24 +773,66 @@ public static function set_item_tags($component, $itemtype, $itemid, context $co
             $tagobjects = array();
         }
 
+        $allowmultiplecontexts = core_tag_area::allows_tagging_in_multiple_contexts($component, $itemtype);
         $currenttags = static::get_item_tags($component, $itemtype, $itemid, self::BOTH_STANDARD_AND_NOT, $tiuserid);
+        $taginstanceidstomovecontext = [];
 
         // For data coherence reasons, it's better to remove deleted tags
         // before adding new data: ordering could be duplicated.
         foreach ($currenttags as $currenttag) {
-            if (!array_key_exists($currenttag->name, $tagobjects)) {
+            $hasbeenrequested = array_key_exists($currenttag->name, $tagobjects);
+            $issamecontext = $currenttag->taginstancecontextid == $context->id;
+
+            if ($allowmultiplecontexts) {
+                // If the tag area allows multiple contexts then we should only be
+                // managing tags in the given $context. All other tags can be ignored.
+                $shoulddelete = $issamecontext && !$hasbeenrequested;
+            } else {
+                // If the tag area only allows tag instances in a single context then
+                // all tags that aren't in the requested tags should be deleted, regardless
+                // of their context, if they are not part of the new set of tags.
+                $shoulddelete = !$hasbeenrequested;
+                // If the tag instance isn't in the correct context (legacy data)
+                // then we should take this opportunity to update it with the correct
+                // context id.
+                if (!$shoulddelete && !$issamecontext) {
+                    $currenttag->taginstancecontextid = $context->id;
+                    $taginstanceidstomovecontext[] = $currenttag->taginstanceid;
+                }
+            }
+
+            if ($shoulddelete) {
                 $taginstance = (object)array('id' => $currenttag->taginstanceid,
                     'itemtype' => $itemtype, 'itemid' => $itemid,
                     'contextid' => $currenttag->taginstancecontextid, 'tiuserid' => $tiuserid);
                 $currenttag->delete_instance_as_record($taginstance, false);
             }
         }
 
+        if (!empty($taginstanceidstomovecontext)) {
+            static::change_instances_context($taginstanceidstomovecontext, $context);
+        }
+
         $ordering = -1;
         foreach ($tagobjects as $name => $tag) {
             $ordering++;
             foreach ($currenttags as $currenttag) {
-                if (strval($currenttag->name) === strval($name)) {
+                $namesmatch = strval($currenttag->name) === strval($name);
+
+                if ($allowmultiplecontexts) {
+                    // If the tag area allows multiple contexts then we should only
+                    // skip adding a new instance if the existing one is in the correct
+                    // context.
+                    $contextsmatch = $currenttag->taginstancecontextid == $context->id;
+                    $shouldskipinstance = $namesmatch && $contextsmatch;
+                } else {
+                    // The existing behaviour for single context tag areas is to
+                    // skip adding a new instance regardless of whether the existing
+                    // instance is in the same context as the provided $context.
+                    $shouldskipinstance = $namesmatch;
+                }
+
+                if ($shouldskipinstance) {
                     if ($currenttag->ordering != $ordering) {
                         $currenttag->update_instance_ordering($currenttag->taginstanceid, $ordering);
                     }

diff --git a/version.php b/version.php
@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2018022800.01;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2018022800.03;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.