diff --git a/tag/lib.php b/tag/lib.php index d6a1b533239..788c49e25a5 100644 --- a/tag/lib.php +++ b/tag/lib.php @@ -1,311 +1,751 @@ -id, $array_of_tags); - * - * - to "remove all the tags on a blog post": - * tag_set('post', $blog_post->id, array()); - * - * Tag set will create tags that need to be created. + * @param string $tag_names_csv CSV tag names (can be unnormalized) to be created. + * @param string $tag_type type of tag to be created ("default" is the default value). + * @return an array of tags ids, indexed by their normalized names */ +function tag_create($tag_names_csv, $tag_type="default") { + global $USER; + $textlib = textlib_get_instance(); -define('TAG_RETURN_ARRAY', 0); -define('TAG_RETURN_OBJECT', 1); -define('TAG_RETURN_TEXT', 2); -define('TAG_RETURN_HTML', 3); + $tags = explode(",", $tag_names_csv ); -define('TAG_CASE_LOWER', 0); -define('TAG_CASE_ORIGINAL', 1); + $tag_object = new StdClass; + $tag_object->tagtype = $tag_type; + $tag_object->userid = $USER->id; -require_once($CFG->dirroot .'/tag/locallib.php'); + $systemcontext = get_context_instance(CONTEXT_SYSTEM); + $can_create_tags = has_capability('moodle/tag:create',$systemcontext); -/////////////////////////////////////////////////////// -/////////////////// PUBLIC TAG API //////////////////// + $norm_tag_names_csv = ''; + foreach ($tags as $tag) { -/** - * Delete one or more tag, and all their instances if there are any left. - * - * @param mixed $tagids one tagid (int), or one array of tagids to delete - * @return bool true on success, false otherwise - */ -function tag_delete($tagids) { + // rawname keeps the original casing of the string + $tag_object->rawname = tag_normalize($tag, false); - if (!is_array($tagids)) { - $tagids = array($tagids); - } + // name lowercases the string + $tag_object->name = tag_normalize($tag); + $norm_tag_names_csv .= $tag_object->name . ','; - $success = true; - foreach( $tagids as $tagid ) { - if (is_null($tagid)) { // can happen if tag doesn't exists - continue; - } - // only delete the main entry if there were no problems deleting all the - // instances - that (and the fact we won't often delete lots of tags) - // is the reason for not using delete_records_select() - if ( delete_records('tag_instance', 'tagid', $tagid) ) { - $success &= (bool) delete_records('tag', 'id', $tagid); + $tag_object->timemodified = time(); + + $exists = record_exists('tag', 'name', $tag_object->name); + + if ( !$exists && is_tag_name_valid($tag_object->name) ) { + if ($can_create_tags) { + insert_record('tag', $tag_object); + } + else { + require_capability('moodle/tag:create',$systemcontext); + } } } - return $success; + $norm_tag_names_csv = $textlib->substr($norm_tag_names_csv,0,-1); + + return tags_id( $norm_tag_names_csv ); + } /** - * Delete one instance of a tag. If the last instance was deleted, it will - * also delete the tag, unless it's type is 'official'. + * Deletes tags * - * @param array $record the record for which to remove the instance - * @param int $tagid the tagid that needs to be removed - * @return bool true on success, false otherwise + * Ex 1: tag_delete('a very cool tag, another nice tag') + * Will delete the tags with names 'a very cool tag' and 'another nice tag' from the 'tags' table, if they exist! + * + * Ex 2: tag_delete('computers, 123, 143, algorithms') + * Will delete tags with names 'computers' and 'algorithms' and tags with ids 123 and 143. + * + * + * @param string $tag_names_or_ids_csv **normalized** tag names or ids of the tags to be deleted. */ -function tag_delete_instance($record, $tagid) { - global $CFG; - if ( delete_records('tag_instance', 'tagid', $tagid, 'itemtype', $record['type'], 'itemid', $record['id']) ) { - if ( !record_exists_sql('SELECT * FROM '. $CFG->prefix .'tag tg, '. $CFG->prefix .'tag_instance ti '. - 'WHERE (tg.id = ti.tagid AND ti.tagid = '. $tagid .') OR '. - '(tg.id = '. $tagid .' AND tg.tagtype = "official")') ) { - return tag_delete($tagid); - } +function tag_delete($tag_names_or_ids_csv) { + + //covert all names to ids + $tag_ids_csv = tag_id_from_string($tag_names_or_ids_csv); + + //put apostrophes + $tag_ids_csv_with_apos = "'" . str_replace(',', "','", $tag_ids_csv) . "'"; + + // tag instances needs to be deleted as well + // delete_records_select('tag_instance',"tagid IN ($tag_ids_csv_with_apos)"); + // Luiz: (in near future) tag instances should be cascade deleted by RDMS referential integrity constraints, when moodle implements it + // For now, tag_instance orphans should be removed using tag_instance_table_cleanup() + + $return1 = delete_records_select('tag',"name IN ($tag_ids_csv_with_apos)"); + $return2 = delete_records_select('tag',"id IN ($tag_ids_csv_with_apos)"); + + return $return1 && $return2; + +} + +/** + * Get all tags from the records + * + * @param string $tag_types_csv (optional, default value is "default". If '*' is passed, tags of any type will be returned). + * @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter). + * @param string $fields a comma separated list of fields to return + * (optional, by default 'id, tagtype, name, rawname, flag'). The first field will be used as key for the + * array so must be a unique field such as 'id'. + */ +function get_all_tags($tag_types_csv="default", $sort='name ASC', $fields=DEFAULT_TAG_TABLE_FIELDS) { + + if ($tag_types_csv == '*'){ + return get_records('tag', '', '', $sort, $fields); + } + + $tag_types_csv_with_apos = "'" . str_replace(',', "','", $tag_types_csv ) . "'"; + + return get_records_list('tag', 'tagtype', $tag_types_csv_with_apos, $sort, $fields); +} + +/** + * Determines if a tag exists + * + * @param string $tag_name_or_id **normalized** tag name, or an id. + * @return true if exists or false otherwise + * + */ +function tag_exists($tag_name_or_id) { + + if (is_numeric($tag_name_or_id)) { + return record_exists('tag', 'id', $tag_name_or_id); + } else { + // normalised tag names are always lowercase only + return record_exists('tag', 'name', moodle_strtolower($tag_name_or_id)); + } +} + +/** + * Function that returns the id of a tag + * + * @param String $tag_name **normalized** name of the tag + * @return int id of the matching tag + */ +function tag_id($tag_name) { + $tag = get_record('tag', 'name', trim($tag_name), '', '', '', '', 'id'); + + if ($tag){ + return $tag->id; + } + else{ return false; } } /** - * Function that returns the name that should be displayed for a specific tag + * Function that returns the ids of tags * - * @param object $tag_object a line out of tag table, as returned by the adobd functions - * @return string + * Ex: tags_id('computers, algorithms') + * + * @param String $tag_names_csv comma separated **normalized** tag names. + * @return Array array with the tags ids, indexed by their **normalized** names */ -function tag_display_name($tag_object) { +function tags_id($tag_names_csv) { - if(!isset($tag_object->name)) { + $normalized_tag_names_csv = tag_normalize($tag_names_csv); + $tag_names_csv_with_apos = "'" . str_replace(',', "','", $normalized_tag_names_csv ) . "'"; + + $tags_ids = array(); + + if ($tag_objects = get_records_list('tag','name', $tag_names_csv_with_apos, "" , "name, id" )) { + foreach ($tag_objects as $tag) { + $tags_ids[$tag->name] = $tag->id; + } + } + + return $tags_ids; +} + +/** + * Function that returns the name of a tag + * + * @param int $tag_id id of the tag + * @return String name of the tag with the id passed + */ +function tag_name($tag_id) { + $tag = get_record('tag', 'id', $tag_id, '', '', '', '', 'name'); + + if ($tag){ + return $tag->name; + } + else{ return ''; } +} + +/** + * Function that retrieves the names of tags given their ids + * + * @param String $tag_ids_csv comma separated tag ids + * @return Array an array with the tags names, indexed by their ids + */ + +function tags_name($tag_ids_csv) { + + //remove any white spaces + $tag_ids_csv = str_replace(' ', '', $tag_ids_csv); + + $tag_ids_csv_with_apos = "'" . str_replace(',', "','", $tag_ids_csv ) . "'"; + + $tag_objects = get_records_list('tag','id', $tag_ids_csv_with_apos, "" , "name, id" ); + + $tags_names = array(); + foreach ($tag_objects as $tag) { + $tags_names[$tag->id] = $tag->name; + } + + return $tags_names; +} + +/** + * Function that returns the name of a tag for display. + * + * @param mixed $tag_object + * @return string + */ +function tag_display_name($tag_object){ + + global $CFG; if( empty($CFG->keeptagnamecase) ) { //this is the normalized tag name $textlib = textlib_get_instance(); - return htmlspecialchars($textlib->strtotitle($tag_object->name)); + return $textlib->strtotitle($tag_object->name); } else { //original casing of the tag name - return htmlspecialchars($tag_object->rawname); + return $tag_object->rawname; } + } /** - * Find all records tagged with a tag of a given type ('post', 'user', etc.) + * Function that retrieves a tag object by its id * - * @param string $tag tag to look for - * @param string $type type to restrict search to. If null, every matching - * record will be returned - * @return array of matching objects, indexed by record id, from the table containing the type requested + * @param String $tag_id + * @return mixed a fieldset object containing the first matching record, or false if none found */ -function tag_find_records($tag, $type) { - - global $CFG; +function tag_by_id($tag_id) { - if (!$tag || !$type) { - return array(); - } - - $tagid = tag_get_id($tag); - - $query = "SELECT it.* ". - "FROM {$CFG->prefix}{$type} it INNER JOIN {$CFG->prefix}tag_instance tt ON it.id = tt.itemid ". - "WHERE tt.itemtype = '{$type}' AND tt.tagid = '{$tagid}'"; - - return get_records_sql($query); + return get_record('tag','id',$tag_id); } /** - * Get the array of db record of tags associated to a record (instances). Use - * tag_get_tags_csv to get the same information in a comma-separated string. + * Function that retrieves a tag object by its name * - * @param array $record the record for which we want to get the tags - * @param string $type the tag type (either 'default' or 'official'). By default, - * all tags are returned. - * @return array the array of tags + * @param String $tag_name + * @return mixed a fieldset object containing the first matching record, or false if none found */ -function tag_get_tags($record, $type=null) { - - global $CFG; - - if ($type) { - $type = "AND tg.tagtype = '$type'"; - } - - $tags = get_records_sql('SELECT tg.id, tg.tagtype, tg.name, tg.rawname, tg.flag, ti.ordering '. - 'FROM '. $CFG->prefix .'tag_instance ti INNER JOIN '. $CFG->prefix .'tag tg ON tg.id = ti.tagid '. - 'WHERE ti.itemtype = "'. $record['type'] .'" AND ti.itemid = "'. $record['id'] .'" '. $type .' '. - 'ORDER BY ti.ordering ASC'); - // This version of the query, reversing the ON clause, "correctly" returns - // a row with NULL values for instances that are still in the DB even though - // the tag has been deleted. This shouldn't happen, but if it did, using - // this query could help "clean it up". This causes bugs at this time. - //$tags = get_records_sql('SELECT ti.tagid, tg.tagtype, tg.name, tg.rawname, tg.flag, ti.ordering '. - // 'FROM '. $CFG->prefix .'tag_instance ti LEFT JOIN '. $CFG->prefix .'tag tg ON ti.tagid = tg.id '. - // 'WHERE ti.itemtype = "'. $record['type'] .'" AND ti.itemid = "'. $record['id'] .'" '. $type .' '. - // 'ORDER BY ti.ordering ASC'); - - if (!$tags) { - return array(); - } else { - return $tags; - } +function tag_by_name($tag_name) { + $tag = get_record('tag','name',$tag_name); + return $tag; } /** - * Get the array of tags display names, indexed by id. - * - * @param array $record the record for which we want to get the tags - * @param string $type the tag type (either 'default' or 'official'). By default, - * all tags are returned. - * @return array the array of tags (with the value returned by tag_display_name), indexed by id - */ -function tag_get_tags_array($record, $type=null) { - $tags = array(); - foreach(tag_get_tags($record, $type) as $tag) { - $tags[$tag->id] = tag_display_name($tag); - } - return $tags; -} - -/** - * Get a comma-separated string of tags associated to a record. Use tag_get_tags - * to get the same information in an array. + * In a comma separated string of ids or names of tags, replaces all tag names with their correspoding ids * - * @param array $record the record for which we want to get the tags - * @param int $html either TAG_RETURN_HTML or TAG_RETURN_TEXT, depending - * on the type of output desired - * @param string $type either 'official' or 'default', if null, all tags are - * returned - * @return string the comma-separated list of tags. - */ -function tag_get_tags_csv($record, $html=TAG_RETURN_HTML, $type=null) { - global $CFG; - - $tags_names = array(); - foreach( tag_get_tags($record, $type) as $tag ) { - if ($html == TAG_RETURN_TEXT) { - $tags_names[] = tag_display_name($tag); - } else { // TAG_RETURN_HTML - $tags_names[] = ''. tag_display_name($tag) .''; - } - } - return implode(', ', $tags_names); -} - -/** - * Get an array of tag ids associated to a record. + * Ex: + * Suppose the DB contains only the following entries in the tags table: + * id name + * 10 moodle + * 12 science + * 22 education * - * @param array $record the record for which we want to get the tags - * @return array of tag ids, indexed and sorted by 'ordering' + * tag_id_from_string('moodle, 12, education, programming, 33, 11') + * will return '10,12,22,,33,11' + * + * This is a helper function used by functions of this API to process function arguments ($tag_name_or_id) + * + * @param string $tag_names_or_ids_csv comma separated **normalized** names or ids of tags + * @return int comma separated ids of the tags */ -function tag_get_tags_ids($record) { - +function tag_id_from_string($tag_names_or_ids_csv) { + + $tag_names_or_ids = explode(',', $tag_names_or_ids_csv); + $tag_ids = array(); - foreach( tag_get_tags($record) as $tag ) { - $tag_ids[$tag->ordering] = $tag->id; - } - ksort($tag_ids); - return $tag_ids; -} + foreach ($tag_names_or_ids as $name_or_id) { -/** - * Returns the database ID of a set of tags. - * - * @param mixed $tags one tag, or array of tags, to look for. - * @param bool $return_object get the object returned by get_recordset_sql instead - * of the id only (default: false) - * @return mixed tag-indexed array of ids (or objects, if second parameter is TAG_RETURN_OBJECT), or only an int, if only one tag is given *and* the second parameter is null. No value for a key means the tag wasn't found. - */ -function tag_get_id($tags, $return_value=null) { - global $CFG; - static $tag_id_cache = array(); - - $return_an_int = false; - if (!is_array($tags)) { - if(is_null($return_value) || $return_value == TAG_RETURN_OBJECT) { - $return_an_int = true; + if (is_numeric($name_or_id)){ + $tag_ids[] = trim($name_or_id); } - $tags = array($tags); - } - - $result = array(); - - //TODO: test this and see if it helps performance without breaking anything - //foreach($tags as $key => $tag) { - // $clean_tag = moodle_strtolower($tag); - // if ( array_key_exists($clean_tag), $tag_id_cache) ) { - // $result[$clean_tag] = $tag_id_cache[$clean_tag]; - // $tags[$key] = ''; // prevent further processing for this one. - // } - //} - - $tags = array_values(tag_normalize($tags)); - foreach($tags as $key => $tag) { - $tags[$key] = addslashes(moodle_strtolower($tag)); - $result[moodle_strtolower($tag)] = null; // key must exists : no value for a key means the tag wasn't found. - } - $tag_string = "'". implode("', '", $tags) ."'"; - - if ($rs = get_recordset_sql('SELECT * FROM '. $CFG->prefix .'tag WHERE name in ('. $tag_string .') order by name')) { - while ($record = rs_fetch_next_record($rs)) { - if ($return_value == TAG_RETURN_OBJECT) { - $result[$record->name] = $record; - } else { // TAG_RETURN_ARRAY - $result[$record->name] = $record->id; - } + elseif (is_string($name_or_id)) { + $tag_ids[] = tag_id( $name_or_id ); } + } - if ($return_an_int) { - return array_pop($result); - } + $tag_ids_csv = implode(',',$tag_ids); + $tag_ids_csv = str_replace(' ', '', $tag_ids_csv); - return $result; + return $tag_ids_csv; } /** - * Get a tag as an object (line) returned by get_recordset_sql + * In a comma separated string of ids or names of tags, replaces all tag ids with their correspoding names * - * @param int $tagid a tag id - * @return object a line returned from get_recordset_sql, or false + * Ex: + * Suppose the DB contains only the following entries in the tags table: + * id name + * 10 moodle + * 12 science + * 22 education + * + * tag_name_from_string('mOOdle, 10, HiStOrY, 17, 22') + * will return the string 'mOOdle,moodle,HiStOrY,,education' + * + * This is a helper function used by functions of this API to process function arguments ($tag_name_or_id) + * + * @param string $tag_names_or_ids_csv comma separated names or ids of tags + * @return int comma separated names of the tags */ -function tag_get_tag_by_id($tagid) { +function tag_name_from_string($tag_names_or_ids_csv) { + + $tag_names_or_ids = explode(',', $tag_names_or_ids_csv); + + $tag_names = array(); + foreach ($tag_names_or_ids as $name_or_id) { + + if (is_numeric($name_or_id)){ + $tag_names[] = tag_name($name_or_id); + } + elseif (is_string($name_or_id)) { + $tag_names[] = trim($name_or_id); + } + + } + + $tag_names_csv = implode(',',$tag_names); + + return $tag_names_csv; + +} + + +/** + * Determines if a tag name is valid + * + * @param string $name + * @return boolean + */ +function is_tag_name_valid($name){ + + $normalized = tag_normalize($name); + + return !strcmp($normalized, $name) && !empty($name) && !is_numeric($name); + +} + + +/** + * Associates a tag with an item + * + * Ex 1: tag_an_item('user', '1', 'hisTOrY, RELIGIONS, roman' ) + * This will tag an user whose id is 1 with "history", "religions", "roman" + * If the tag names passed do not exist, they will get created. + * + * Ex 2: tag_an_item('user', '1', 'hisTory, 12, 11, roman') + * This will tag an user whose id is 1 with 'history', 'roman' and with tags of ids 12 and 11 + * + * @param string $item_type name of the table where the item is stored. Ex: 'user' + * @param string $item_id id of the item to be tagged + * @param string $tag_names_or_ids_csv comma separated tag names (can be unormalized) or ids of existing tags + * @param string $tag_type type of the tags that are beeing added (optional, default value is "default") + */ + +function tag_an_item($item_type, $item_id, $tag_names_or_ids_csv, $tag_type="default") { + global $CFG; - $rs = get_recordset_sql('SELECT * FROM '. $CFG->prefix .'tag WHERE id = '. $tagid); - return rs_fetch_next_record($rs); + //convert any tag ids passed to their corresponding tag names + $tag_names_csv = tag_name_from_string($tag_names_or_ids_csv); + + //create the tags + $tags_created_ids = tag_create($tag_names_csv,$tag_type); + + //tag instances of an item are ordered, get the last one + $query = " + SELECT + MAX(ordering) AS max_order + FROM + {$CFG->prefix}tag_instance ti + WHERE + ti.itemtype = '{$item_type}' + AND + ti.itemid = '{$item_id}' + "; + + $max_order = get_field_sql($query); + + $tag_names = explode(',', tag_normalize($tag_names_csv)); + + $ordering = array(); + foreach($tag_names as $tag_name){ + $ordering[$tag_name] = ++$max_order; + } + + //setup tag_instance object + $tag_instance = new StdClass; + $tag_instance->itemtype = $item_type; + $tag_instance->itemid = $item_id; + + + //create tag instances + foreach ($tags_created_ids as $tag_normalized_name => $tag_id) { + + $tag_instance->tagid = $tag_id; + $tag_instance->ordering = $ordering[$tag_normalized_name]; + $tag_instance->timemodified = time(); + $tag_instance_exists = get_record('tag_instance', 'tagid', $tag_id, 'itemtype', $item_type, 'itemid', $item_id); + + if (!$tag_instance_exists) { + insert_record('tag_instance',$tag_instance); + } + else { + $tag_instance_exists->timemodified = time(); + $tag_instance_exists->ordering = $ordering[$tag_normalized_name]; + update_record('tag_instance',$tag_instance_exists); + } + } + + + // update_tag_correlations($item_type, $item_id); + +} + + +/** + * Updates the tags associated with an item + * + * Ex 1: + * Suppose user 1 is tagged only with "algorithms", "computers" and "software" + * By calling update_item_tags('user', 1, 'algorithms, software, mathematics') + * User 1 will now be tagged only with "algorithms", "software" and "mathematics" + * + * Ex 2: + * update_item_tags('user', '1', 'algorithms, 12, 13') + * User 1 will now be tagged only with "algorithms", and with tags of ids 12 and 13 + * + * + * @param string $item_type name of the table where the item is stored. Ex: 'user' + * @param string $item_id id of the item to be tagged + * @param string $tag_names_or_ids_csv comma separated tag names (can be unormalized) or ids of existing tags + * @param string $tag_type type of the tags that are beeing added (optional, default value is "default") + */ + +function update_item_tags($item_type, $item_id, $tag_names_or_ids_csv, $tag_type="default") { + + //if $tag_names_csv is an empty string, remove all tag associations of the item + if( empty($tag_names_or_ids_csv) ){ + untag_an_item($item_type, $item_id); + return; + } + + //convert any tag ids passed to their corresponding tag names + $tag_names_csv = tag_name_from_string($tag_names_or_ids_csv); + + //associate the tags passed with the item + tag_an_item($item_type, $item_id, $tag_names_csv, $tag_type ); + + //get the ids of the tags passed + $existing_and_new_tags_ids = tags_id( tag_normalize($tag_names_csv) ); + + // delete any tag instance with $item_type and $item_id + // that are not in $tag_names_csv + $tags_id_csv = "'" . implode("','", $existing_and_new_tags_ids) . "'" ; + + $select = " + itemid = '{$item_id}' + AND + itemtype = '{$item_type}' + AND + tagid NOT IN ({$tags_id_csv}) + "; + + delete_records_select('tag_instance', $select); + +} + +/** + * Removes the association of an item with a tag + * + * Ex: untag_an_item('user', '1', 'history, 11, roman' ) + * The user with id 1 will no longer be tagged with 'history', 'roman' and the tag of id 11 + * Calling untag_an_item('user','1') will remove all tags associated with user 1. + * + * @param string $item_type name of the table where the item is stored. Ex: 'user' + * @param string $item_id id of the item to be untagged + * @param string $tag_names_or_ids_csv comma separated tag **normalized** names or ids of existing tags (optional, if none is given, all tags of the item will be removed) + */ + +function untag_an_item($item_type, $item_id, $tag_names_or_ids_csv='') { + + if ($tag_names_or_ids_csv == ""){ + + delete_records('tag_instance','itemtype', $item_type, 'itemid', $item_id); + + } + else { + + $tag_ids_csv = tag_id_from_string($tag_names_or_ids_csv); + + $tag_ids_csv_with_apos = "'" . str_replace(',', "','", $tag_ids_csv ) . "'"; + + delete_records_select('tag_instance', + "tagid IN ({$tag_ids_csv_with_apos}) AND itemtype='$item_type' AND itemid='$item_id'"); + } + + //update_tag_correlations($item_type, $item_id); + +} + +/** + * Function that gets the tags that are associated with an item + * + * Ex: get_item_tags('user', '1') + * + * @param string $item_type name of the table where the item is stored. Ex: 'user' + * @param string $item_id id of the item beeing queried + * @param string $sort an order to sort the results in, a valid SQL ORDER BY parameter (default is 'ti.ordering ASC') + * @param string $fields tag fields to be selected (optional, default is 'id, name, rawname, tagtype, flag') + * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). + * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). + * @return mixed an array of objects, or false if no records were found or an error occured. + */ + +function get_item_tags($item_type, $item_id, $sort='ti.ordering ASC', $fields=DEFAULT_TAG_TABLE_FIELDS, $limitfrom='', $limitnum='', $tagtype='') { + + global $CFG; + + $fields = 'tg.' . $fields; + $fields = str_replace(',', ',tg.', $fields); + + if ($sort) { + $sort = ' ORDER BY '. $sort; + } + + if ($tagtype) { + $tagwhere = " AND tg.tagtype = '$tagtype' "; + } else { + $tagwhere = ''; + } + + $query = " + SELECT + {$fields} + FROM + {$CFG->prefix}tag_instance ti + INNER JOIN + {$CFG->prefix}tag tg + ON + tg.id = ti.tagid + WHERE + ti.itemtype = '{$item_type}' AND + ti.itemid = '{$item_id}' + $tagwhere + {$sort} + "; + + return get_records_sql($query, $limitfrom, $limitnum); + +} + + + +/** + * Function that returns the items of a certain type associated with a certain tag + * + * Ex 1: get_items_tagged_with('user', 'banana') + * Ex 2: get_items_tagged_with('user', '11') + * + * @param string $item_type name of the table where the item is stored. Ex: 'user' + * @param string $tag_name_or_id is a single **normalized** tag name or the id of a tag + * @param string $sort an order to sort the results in (optional, a valid SQL ORDER BY parameter). + * (to avoid field name ambiguity in the query, use the identifier "it" Ex: 'it.name ASC' ) + * @param string $fields a comma separated list of fields to return + * (optional, by default all fields are returned). The first field will be used as key for the + * array so must be a unique field such as 'id'. ) + * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). + * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). + * @return mixed an array of objects indexed by their ids, or false if no records were found or an error occured. + */ + +function get_items_tagged_with($item_type, $tag_name_or_id, $sort='', $fields='*', $limitfrom='', $limitnum='') { + + global $CFG; + + $tag_id = tag_id_from_string($tag_name_or_id); + + $fields = 'it.' . $fields; + $fields = str_replace(',', ',it.', $fields); + + if ($sort) { + $sort = ' ORDER BY '. $sort; + } + + $query = " + SELECT + {$fields} + FROM + {$CFG->prefix}{$item_type} it + INNER JOIN + {$CFG->prefix}tag_instance tt + ON + it.id = tt.itemid + WHERE + tt.itemtype = '{$item_type}' AND + tt.tagid = '{$tag_id}' + {$sort} + "; + + + return get_records_sql($query, $limitfrom, $limitnum); + +} + +/** + * Returns the number of items tagged with a tag + * + * @param string $tag_name_or_id is a single **normalized** tag name or the id of a tag + * @param string $item_type name of the table where the item is stored. Ex: 'user' (optional, if none is set any + * type will be counted) + * @return int the count. If an error occurrs, 0 is returned. + */ +function count_items_tagged_with($tag_name_or_id, $item_type='') { + + global $CFG; + + $tag_id = tag_id_from_string($tag_name_or_id); + + if (empty($item_type)){ + $query = " + SELECT + COUNT(*) AS count + FROM + {$CFG->prefix}tag_instance tt + WHERE + tagid = {$tag_id}"; + } + else + { + $query = " + SELECT + COUNT(*) AS count + FROM + {$CFG->prefix}{$item_type} it + INNER JOIN + {$CFG->prefix}tag_instance tt + ON + it.id = tt.itemid + WHERE + tt.itemtype = '{$item_type}' AND + tt.tagid = '{$tag_id}' "; + } + + + return count_records_sql($query); + +} + + +/** + * Determines if an item is tagged with a certain tag + * + * @param string $item_type name of the table where the item is stored. Ex: 'user' + * @param string $item_id id of the item beeing queried + * @param string $tag_name_or_id is a single **normalized** tag name or the id of a tag + * @return bool true if a matching record exists, else false. + */ +function is_item_tagged_with($item_type,$item_id, $tag_name_or_id) { + + $tag_id = tag_id_from_string($tag_name_or_id); + + return record_exists('tag_instance','itemtype',$item_type,'itemid',$item_id, 'tagid', $tag_id); +} + +/** + * Search for tags with names that match some text + * + * @param string $text string that the tag names will be matched against + * @param boolean $ordered If true, tags are ordered by their popularity. If false, no ordering. + * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). + * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). + * @return mixed an array of objects, or false if no records were found or an error occured. + */ + +function search_tags($text, $ordered=true, $limitfrom='' , $limitnum='' ) { + + global $CFG; + + $text = tag_normalize($text); + + if ($ordered) { + $query = " + SELECT + tg.id, tg.name, tg.rawname, COUNT(ti.id) AS count + FROM + {$CFG->prefix}tag tg + LEFT JOIN + {$CFG->prefix}tag_instance ti + ON + tg.id = ti.tagid + WHERE + tg.name + LIKE + '%{$text}%' + GROUP BY + tg.id, tg.name, tg.rawname + ORDER BY + count + DESC"; + } else { + $query = " + SELECT + tg.id, tg.name, tg.rawname + FROM + {$CFG->prefix}tag tg + WHERE + tg.name + LIKE + '%{$text}%' + "; + } + + + return get_records_sql($query, $limitfrom , $limitnum); + +} + +/** + * Function that returns tags that start with some text + * + * @param string $text string that the tag names will be matched against + * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). + * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). + * @return mixed an array of objects, or false if no records were found or an error occured. + */ +function similar_tags($text, $limitfrom='' , $limitnum='' ) { + global $CFG; + + $text = moodle_strtolower($text); + + $query = "SELECT tg.id, tg.name, tg.rawname + FROM {$CFG->prefix}tag tg + WHERE tg.name LIKE '{$text}%'"; + + return get_records_sql($query, $limitfrom , $limitnum); } /** @@ -319,266 +759,69 @@ function tag_get_tag_by_id($tagid) { * @param int $limitnum return a subset comprising this many records (optional, default is 10) * @return array an array of tag objects */ -function tag_get_related_tags($tagid, $limitnum=10) { + +function related_tags($tag_name_or_id, $limitnum=10) { + + $tag_id = tag_id_from_string($tag_name_or_id); //gets the manually added related tags - if (!$related_tags = tag_get_tags(array('type'=>'tag', 'id'=>$tagid))) { - $related_tags = array(); + if (!$manual_related_tags = get_item_tags('tag', $tag_id, 'ti.ordering ASC', DEFAULT_TAG_TABLE_FIELDS)) { + $manual_related_tags = array(); } //gets the correlated tags - $automatic_related_tags = tag_get_correlated($tagid, $limitnum); - if (is_array($automatic_related_tags)) { - $related_tags = array_merge($related_tags, $automatic_related_tags); - } + $automatic_related_tags = correlated_tags($tag_id, $limitnum); + + $related_tags = array_merge($manual_related_tags, $automatic_related_tags); return array_slice(object_array_unique($related_tags), 0 , $limitnum); } -/** - * Get a comma-separated list of tags related to another tag. +/** + * Returns the correlated tags of a tag + * The correlated tags are retrieved from the tag_correlation table, which is a caching table. * - * @param array $related_tags the array returned by tag_get_related_tags - * @param int $html either TAG_RETURN_HTML (default) or TAG_RETURN_TEXT : return html links, or just text. - * @return string comma-separated list + * @param string $tag_name_or_id is a single **normalized** tag name or the id of a tag + * @return array an array of tag objects, or empty array if none */ -function tag_get_related_tags_csv($related_tags, $html=TAG_RETURN_HTML) { - global $CFG; +function correlated_tags($tag_name_or_id, $limitnum=null) { - $tags_names = array(); - foreach($related_tags as $tag) { - if ( $html == TAG_RETURN_TEXT) { - $tags_names[] = rawurlencode(tag_display_name($tag)); - } else { - // TAG_RETURN_HTML - $tags_names[] = ''. rawurlencode(tag_display_name($tag)) .''; - } + $tag_id = tag_id_from_string($tag_name_or_id); + + if (!$tag_correlation = get_record('tag_correlation', 'tagid', $tag_id)) { + return array(); } - return implode(', ', $tags_names); + + if (empty($tag_correlation->correlatedtags)) { + return array(); + } + + if (!$result = get_records_select('tag', "id IN ({$tag_correlation->correlatedtags})", '', DEFAULT_TAG_TABLE_FIELDS, 0, $limitnum)) { + return array(); + } + + return $result; } /** - * Change the "value" of a tag, and update the associated 'name'. + * Recalculates tag correlations of all the tags associated with an item + * This function could be called whenever the tags associations with an item changes + * ( for example when tag_an_item() or untag_an_item() is called ) * - * @param int $tagid the id of the tag to modify - * @param string $newtag the new name - * @return bool true on success, false otherwise + * @param string $item_type name of the table where the item is stored. Ex: 'user' + * @param string $item_id id of the item */ -function tag_rename($tagid, $newtag) { +function update_tag_correlations($item_type, $item_id) { - if (! $newtag_clean = array_shift(tag_normalize($newtag, TAG_CASE_ORIGINAL)) ) { - return false; - } + $item_tags = get_item_tags($item_type, $item_id); - if ( tag_get_id($newtag_clean) ) { - // 'newtag' already exists and merging tags is not yet supported. - return false; - } - - if ($tag = get_record('tag', 'id', $tagid)) { - $tag->rawname = addslashes($newtag_clean); - $tag->name = addslashes(moodle_strtolower($newtag_clean)); - $tag->timemodified = time(); - return update_record('tag', $tag); - } - return false; -} - -/** - * Set the tags assigned to a record. This overwrites the current tags. - * - * This function is meant to be fed the string coming up from the user - * interface, which contains all tags assigned to a record. - * - * @param string $record_type the type of record to tag ('post' for blogs, - * 'user' for users, 'tag' for tags, etc. - * @param int $record_id the id of the record to tag - * @param array $tags the array of tags to set on the record. If - * given an empty array, all tags will be removed. - * @return void - */ -function tag_set($record_type, $record_id, $tags) { - global $db; - - $record = array('type' => $record_type, 'id' => $record_id); - - $tags_ids = tag_get_id($tags, TAG_RETURN_ARRAY); // force an array, even if we only have one tag. - $cleaned_tags = tag_normalize($tags); - //echo 'tags-in-tag_set'; var_dump($tags); var_dump($tags_ids); var_dump($cleaned_tags); - - $current_ids = tag_get_tags_ids($record); - //var_dump($current_ids); - $tags_to_assign = array(); - - // for data coherence reasons, it's better to remove deleted tags - // before adding new data: ordering could be duplicated. - foreach($current_ids as $current_id) { - if (!in_array($current_id, $tags_ids)) { - tag_delete_instance($record, $current_id); - } - } - - foreach($tags as $ordering => $tag) { - $tag = trim($tag); - if (!$tag) { - continue; - } - - $clean_tag = $cleaned_tags[$tag]; - $tag_current_id = $tags_ids[$clean_tag]; - - if ( is_null($tag_current_id) ) { - // create new tags - //echo "call to add tag $tag\n"; - $new_tag = tag_add($tag); - tag_assign($record, $new_tag[$clean_tag], $ordering); - } - elseif ( empty($current_ids) || !in_array($tag_current_id, $current_ids) ) { - // assign existing tags - tag_assign($record, $tag_current_id, $ordering); - } - elseif ( isset($current_ids[$ordering]) && $current_ids[$ordering] != $tag_current_id ) { - // this actually checks if the ordering number points to the same tag - //recompute ordering, if necessary - //echo 'ordering changed for ', $tag, ':', $ordering, "\n"; - tag_assign($record, $tag_current_id, $ordering); - } + foreach ($item_tags as $tag) { + cache_correlated_tags($tag->id); } } /** - * Adds a tag to a record, without overwriting the current tags. - * - * @param string $record_type the type of record to tag ('post' for blogs, - * 'user' for users, etc. - * @param int $record_id the id of the record to tag - * @param string $tag the tag to add - * @return void - */ -function tag_set_add($record_type, $record_id, $tag) { - - $record = array('type' => $record_type, 'id' => $record_id); - - $new_tags = array(); - foreach( tag_get_tags($record) as $current_tag ) { - $new_tags[] = $current_tag->rawname; - } - $new_tags[] = $tag; - - return tag_set($record_type, $record_id, $new_tags); -} - -/** - * Set the type of a tag. At this time (version 1.9) the possible values - * are 'default' or 'official'. Official tags will be displayed separately "at - * tagging time" (while selecting the tags to apply to a record). - * - * @param string $tagid tagid to modify - * @param string $type either 'default' or 'official' - * @return true on success, false otherwise - */ -function tag_type_set($tagid, $type) { - if ($tag = get_record('tag', 'id', $tagid)) { - $tag->tagtype = $type; - $tag->timemodified = time(); - return update_record('tag', $tag); - } - return false; -} - -/////////////////////////////////////////////////////// -/////////////////// PRIVATE TAG API /////////////////// - -/** - * A * @param array $record the record that will be tagged - * @param string $tags the comma-separated tags to set on the record. If - * given an empty array, all tags will be removed. -dds one or more tag in the database. This function should not be called - * directly : you should use tag_set. - * - * @param mixed $tags one tag, or an array of tags, to be created - * @param string $tag_type type of tag to be created ("default" is the default - * value and "official" is the only other supported value at this time). An - * official tag is kept even if there are no records tagged with it. - * @return an array of tags ids, indexed by their lowercase normalized names. - * Any boolean false in the array indicates an error while adding the tag. - */ -function tag_add($tags, $type="default") { - global $USER; - - require_capability('moodle/tag:create', get_context_instance(CONTEXT_SYSTEM)); - - if (!is_array($tags)) { - $tags = array($tags); - } - - $tag_object = new StdClass; - $tag_object->tagtype = $type; - $tag_object->userid = $USER->id; - $tag_object->timemodified = time(); - - $clean_tags = tag_normalize($tags, TAG_CASE_ORIGINAL); - - $tags_ids = array(); - foreach($clean_tags as $tag) { - $tag = trim($tag); - if (!$tag) { - $tags_ids[$tag] = false; - } else { - // note that the difference between rawname and name is only - // capitalization : the rawname is NOT the same at the rawtag. - $tag_object->rawname = addslashes($tag); - $tag_name_lc = moodle_strtolower($tag); - $tag_object->name = addslashes($tag_name_lc); - //var_dump($tag_object); - $tags_ids[$tag_name_lc] = insert_record('tag', $tag_object); - } - } - - return $tags_ids; -} - -/** - * Assigns a tag to a record: if the record already exists, the time and - * ordering will be updated. - * - * @param array $record the record that will be tagged - * @param string $tagid the tag id to set on the record. - * @param int $ordering the order of the instance for this record - * @return bool true on success, false otherwise - */ -function tag_assign($record, $tagid, $ordering) { - - require_capability('moodle/tag:create', get_context_instance(CONTEXT_SYSTEM)); - - if ( $tag_instance_object = get_record('tag_instance', 'tagid', $tagid, 'itemtype', $record['type'], 'itemid', $record['id']) ) { - $tag_instance_object->ordering = $ordering; - $tag_instance_object->timemodified = time(); - return update_record('tag_instance', $tag_instance_object); - } else { - $tag_instance_object = new StdClass; - $tag_instance_object->tagid = $tagid; - $tag_instance_object->itemid = $record['id']; - $tag_instance_object->itemtype = $record['type']; - $tag_instance_object->ordering = $ordering; - $tag_instance_object->timemodified = time(); - return insert_record('tag_instance', $tag_instance_object); - } -} - -/** - * Function that returns tags that start with some text, for use by the autocomplete feature - * - * @param string $text string that the tag names will be matched against - * @return mixed an array of objects, or false if no records were found or an error occured. - */ -function tag_autocomplete($text) { - global $CFG; - return get_records_sql('SELECT tg.id, tg.name, tg.rawname FROM '. $CFG->prefix .'tag tg WHERE tg.name LIKE "'. moodle_strtolower($text) .'%"'); -} - -/** - * Calculates and stores the correlated tags of all tags. + * Calculates and stores the correlated tags of a tag. * The correlations are stored in the 'tag_correlation' table. * * Two tags are correlated if they appear together a lot. @@ -588,240 +831,707 @@ function tag_autocomplete($text) { * It works as a cache for a potentially heavy load query done at the 'tag_instance' table. * So, the 'tag_correlation' table stores redundant information derived from the 'tag_instance' table. * - * @param number $min_correlation cutoff percentage (optional, default is 2) + * @param string $tag_name_or_id is a single **normalized** tag name or the id of a tag + * @param number $min_correlation cutoff percentage (optional, default is 0.25) + * @param int $limitnum return a subset comprising this many records (optional, default is 10) */ -function tag_compute_correlations($min_correlation=2) { - +function cache_correlated_tags($tag_name_or_id, $min_correlation=2) { global $CFG; - $all_tags = get_records_list('tag'); - + $tag_id = tag_id_from_string($tag_name_or_id); - $tag_correlation_obj = new object(); - foreach($all_tags as $tag) { + // query that counts how many times any tag appears together in items + // with the tag passed as argument ($tag_id) + $query = "SELECT tb.tagid , COUNT(*) AS nr + FROM {$CFG->prefix}tag_instance ta + INNER JOIN {$CFG->prefix}tag_instance tb ON ta.itemid = tb.itemid + WHERE ta.tagid = {$tag_id} AND tb.tagid != {$tag_id} + GROUP BY tb.tagid + ORDER BY nr DESC"; - // query that counts how many times any tag appears together in items - // with the tag passed as argument ($tag_id) - $query = "SELECT tb.tagid , COUNT(*) AS nr ". - "FROM {$CFG->prefix}tag_instance ta INNER JOIN {$CFG->prefix}tag_instance tb ON ta.itemid = tb.itemid ". - "WHERE ta.tagid = {$tag->id} AND tb.tagid != {$tag->id} ". - "GROUP BY tb.tagid ". - "HAVING nr > $min_correlation ". - "ORDER BY nr DESC"; // todo: find out if it's necessary to order. + $correlated = array(); - $correlated = array(); - - // Correlated tags happen when they appear together in more occasions - // than $min_correlation. - if ($tag_correlations = get_records_sql($query)) { - foreach($tag_correlations as $correlation) { - // if($correlation->nr >= $min_correlation){ - $correlated[] = $correlation->tagid; - // } + // Correlated tags happen when they appear together in more occasions + // than $min_correlation. + if ($tag_correlations = get_records_sql($query)) { + foreach($tag_correlations as $correlation) { + if($correlation->nr >= $min_correlation){ + $correlated[] = $correlation->tagid; } } + } - $correlated = implode(',', $correlated); - //var_dump($correlated); + $correlated = implode(',', $correlated); - //saves correlation info in the caching table - if ($tag_correlation_obj = get_record('tag_correlation', 'tagid', $tag->id)) { - $tag_correlation_obj->correlatedtags = $correlated; - update_record('tag_correlation', $tag_correlation_obj); - } else { - $tag_correlation_obj->tagid = $tag->id; - $tag_correlation_obj->correlatedtags = $correlated; - insert_record('tag_correlation', $tag_correlation_obj); - } + //saves correlation info in the caching table + if ($tag_correlation_obj = get_record('tag_correlation', 'tagid', $tag_id)) { + $tag_correlation_obj->correlatedtags = $correlated; + update_record('tag_correlation', $tag_correlation_obj); + + } else { + $tag_correlation_obj = new object(); + $tag_correlation_obj->tagid = $tag_id; + $tag_correlation_obj->correlatedtags = $correlated; + insert_record('tag_correlation', $tag_correlation_obj); } } /** - * Tasks that should be performed at cron time - */ -function tag_cron() { - tag_compute_correlations(); -} - -/** - * Get the name of a tag - * - * @param mixed $tagids the id of the tag, or an array of ids - * @return mixed string name of one tag, or id-indexed array of strings - */ -function tag_get_name($tagids) { - - $return_a_string = false; - if ( !is_array($tagids) ) { - $return_a_string = true; - $tagids = array($tagids); - } - - $tag_names = array(); - foreach(get_records_list('tag', 'id', implode(',', $tagids)) as $tag) { - $tag_names[$tag->id] = $tag->name; - } - - if ($return_a_string) { - return array_pop($tag_names); - } - - return $tag_names; -} - -/** - * Returns the correlated tags of a tag, retrieved from the tag_correlation - * table. Make sure cron runs, otherwise the table will be empty and this - * function won't return anything. + * This function cleans up the 'tag_instance' table + * It removes orphans in 'tag_instances' table * - * @param int $tag_id is a single tag id - * @return array an array of tag objects, empty if no correlated tags are found */ -function tag_get_correlated($tag_id, $limitnum=null) { - - $tag_correlation = get_record('tag_correlation', 'tagid', $tag_id); - - if (!$tag_correlation || empty($tag_correlation->correlatedtags)) { - return array(); - } - - if (!$result = get_records_select('tag', "id IN ({$tag_correlation->correlatedtags})", '', '*', 0, $limitnum)) { - return array(); - } - - return $result; -} - -/** - * Function that normalizes a list of tag names. - * - * @param mixed $tags array of tags, or a single tag. - * @param int $case case to use for returned value (default: lower case). Either CASE_LOWER or CASE_UPPER - * @return array of lowercased normalized tags, indexed by the normalized tag. (Eg: 'Banana' => 'banana') - */ -function tag_normalize($rawtags, $case = TAG_CASE_LOWER) { - - // cache normalized tags, to prevent (in some cases) costly (repeated) calls to clean_param - static $cleaned_tags_lc = array(); // lower case - use for comparison - static $cleaned_tags_mc = array(); // mixed case - use for saving to database - - if ( !is_array($rawtags) ) { - $rawtags = array($rawtags); - } - - $result = array(); - foreach($rawtags as $rawtag) { - $rawtag = trim($rawtag); - if (!$rawtag) { - continue; - } - if ( !array_key_exists($rawtag, $cleaned_tags_lc) ) { - $cleaned_tags_lc[$rawtag] = moodle_strtolower( clean_param($rawtag, PARAM_TAG) ); - $cleaned_tags_mc[$rawtag] = clean_param($rawtag, PARAM_TAG); - } - if ( $case == TAG_CASE_LOWER ) { - $result[$rawtag] = $cleaned_tags_lc[$rawtag]; - } else { // TAG_CASE_ORIGINAL - $result[$rawtag] = $cleaned_tags_mc[$rawtag]; - } - } - - return $result; -} - - -/** - * Search for tags with names that match some text - * - * @param string $text escaped string that the tag names will be matched against - * @param boolean $ordered If true, tags are ordered by their popularity. If false, no ordering. - * @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set). - * @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set). - * @return mixed an array of objects, or false if no records were found or an error occured. - */ -function tag_find_tags($text, $ordered=true, $limitfrom='', $limitnum='') { +function tag_instance_table_cleanup() { global $CFG; - $text = array_shift(tag_normalize($text, TAG_CASE_LOWER)); + //get the itemtypes present in the 'tag_instance' table + $query = " + SELECT + DISTINCT(itemtype) + FROM + {$CFG->prefix}tag_instance + "; - if ($ordered) { - $query = "SELECT tg.id, tg.name, tg.rawname, COUNT(ti.id) AS count ". - "FROM {$CFG->prefix}tag tg LEFT JOIN {$CFG->prefix}tag_instance ti ON tg.id = ti.tagid ". - "WHERE tg.name LIKE '%{$text}%' ". - "GROUP BY tg.id, tg.name, tg.rawname ". - "ORDER BY count DESC"; - } else { - $query = "SELECT tg.id, tg.name, tg.rawname ". - "FROM {$CFG->prefix}tag tg ". - "WHERE tg.name LIKE '%{$text}%'"; + if ($items_types = get_records_sql($query)) { + + // for each itemtype, remove tag_instances that are orphans + // That is: For a given tag_instance, if in the itemtype table there's no entry with id equal to itemid, + // then this tag_instance is an orphan and it will be removed. + foreach ($items_types as $type) { + + $query = " + {$CFG->prefix}tag_instance.id + IN + ( SELECT sq1.id + FROM + (SELECT sq2.* + FROM {$CFG->prefix}tag_instance sq2 + LEFT JOIN {$CFG->prefix}{$type->itemtype} item + ON sq2.itemid = item.id + WHERE item.id IS NULL + AND sq2.itemtype = '{$type->itemtype}') + sq1 + ) "; + + delete_records_select('tag_instance', $query); + } } - return get_records_sql($query, $limitfrom , $limitnum); + + // remove tag_instances that are orphans because tagid does not correspond to an + // existing tag + $query = " + {$CFG->prefix}tag_instance.id + IN + (SELECT sq1.id + FROM + (SELECT sq2.* + FROM {$CFG->prefix}tag_instance sq2 + LEFT JOIN {$CFG->prefix}tag tg + ON sq2.tagid = tg.id + WHERE tg.id IS NULL ) + sq1 + ) + "; + + delete_records_select('tag_instance', $query); } -/////////////////////////////////////////////////////////// -////// functions copied over from the first version ////// /** - * Flag a tag as inapropriate - * - * @param mixed $tagids one (int) tagid, or an array of tagids - * @return void + * Function that normalizes a list of tag names + * + * Ex: tag_normalize('bANAana') -> returns 'banana' + * tag_normalize('lots of spaces') -> returns 'lots of spaces' + * tag_normalize('%!%!% non alpha numeric %!%!%') -> returns 'non alpha numeric' + * tag_normalize('tag one, TAG TWO, TAG three, and anotheR tag') + * -> returns 'tag one,tag two,tag three,and another tag' + * + * @param string $tag_names_csv unnormalized CSV tag names + * @return string **normalized** CSV tag names */ -function tag_set_flag($tagids) { - if ( !is_array($tagids) ) { - $tagids = array($tagids); + +function tag_normalize($tag_names_csv, $lowercase=true) { + $tag_names_csv = clean_param($tag_names_csv, PARAM_TAGLIST); + + if ($lowercase){ + $tag_names_csv = moodle_strtolower($tag_names_csv); } - foreach ($tagids as $tagid) { - $tag = get_record('tag', 'id', $tagid); + + return $tag_names_csv; +} + +function tag_flag_inappropriate($tag_names_or_ids_csv){ + + $tag_ids_csv = tag_id_from_string($tag_names_or_ids_csv); + + $tag_ids = explode(',', $tag_ids_csv); + + foreach ($tag_ids as $id){ + $tag = get_record('tag','id',$id, '', '', '', '', 'id,flag'); + $tag->flag++; $tag->timemodified = time(); + update_record('tag', $tag); } } -/** - * Remove the inapropriate flag on a tag - * - * @param mixed $tagids one (int) tagid, or an array of tagids - * @return bool true if function succeeds, false otherwise - */ -function tag_unset_flag($tagids) { +function tag_flag_reset($tag_names_or_ids_csv){ + global $CFG; - require_capability('moodle/tag:manage', get_context_instance(CONTEXT_SYSTEM)); + $tag_ids_csv = tag_id_from_string($tag_names_or_ids_csv); + + $tag_ids_csv_with_apos = "'" . str_replace(',', "','", $tag_ids_csv) . "'"; - if ( is_array($tagids) ) { - $tagids = implode(',', $tagids); - } $timemodified = time(); - return execute_sql('UPDATE '. $CFG->prefix .'tag tg SET tg.flag = 0, tg.timemodified = '. $timemodified .' WHERE tg.id IN ('. $tagids .')', false); + + $query = " + UPDATE + {$CFG->prefix}tag tg + SET + tg.flag = 0, + tg.timemodified = {$timemodified} + WHERE + tg.id + IN + ({$tag_ids_csv_with_apos}) + "; + + execute_sql($query, false); } /** - * Count how many records are tagged with a specific tag, + * Function that updates tags names. + * Updates only if the new name suggested for a tag doesn´t exist already. * - * @param string $record record to look for ('post', 'user', etc.) - * @param int $tag is a single tag id - * @return int number of mathing tags. + * @param Array $tags_names_changed array of new tag names indexed by tag ids. + * @return Array array of tags names that were effectively updated, indexed by tag ids. */ -function tag_record_count($record_type, $tagid) { - return count_records('tag_instance', 'itemtype', $record_type, 'tagid', $tagid); -} +function tag_update_name($tags_names_changed){ -/** - * Determine if a record is tagged with a specific tag - * - * @param array $record the record to look for - * @param string $tag a tag name - * @return bool true if it is tagged, false otherwise - */ -function tag_record_tagged_with($record, $tag) { - if ($tagid = tag_get_id($tag)) { - return count_records('tag_instance', 'itemtype', $record['type'], 'itemid', $record['id'], 'tagid', $tagid); - } else { - return 0; // tag doesn't exist + $tags_names_updated = array(); + + foreach ($tags_names_changed as $id => $newname){ + + $norm_newname = tag_normalize($newname); + + if( !tag_exists($norm_newname) && is_tag_name_valid($norm_newname) ) { + + $tag = tag_by_id($id); + + $tags_names_updated[$id] = $tag->name; + + // rawname keeps the original casing of the string + $tag->rawname = tag_normalize($newname, false); + + // name lowercases the string + $tag->name = $norm_newname; + + $tag->timemodified = time(); + + update_record('tag',$tag); + + } } + + return $tags_names_updated; + +} + +/** + * Function that returns comma separated HTML links to the tag pages of the tags passed + * + * @param array $tag_objects an array of tag objects + * @return string CSV, HTML links to tag pages + */ + +function tag_links_csv($tag_objects) { + + global $CFG; + $tag_links = ''; + + if (empty($tag_objects)) { + return ''; + } + + $systemcontext = get_context_instance(CONTEXT_SYSTEM); + $can_manage_tags = has_capability('moodle/tag:manage', $systemcontext); + + foreach ($tag_objects as $tag){ + //highlight tags that have been flagged as inappropriate for those who can manage them + $tagname = tag_display_name($tag); + if ($tag->flag > 0 && $can_manage_tags) { + $tagname = '' . $tagname . ''; + } + $tag_links .= ' '.$tagname.','; + } + + return rtrim($tag_links, ','); +} + +/** + * Function that returns comma separated names of the tags passed + * Example of string that might be returned: 'history, wars, greek history' + * + * @param array $tag_objects + * @return string CSV tag names + */ + +function tag_names_csv($tag_objects) { + + if (empty($tag_objects)) { + return ''; + } + + $tags = array(); + + foreach ($tag_objects as $tag){ + $tags[] = tag_display_name($tag); + } + + return implode(', ', $tags); +} + + +/** + * Returns most popular tags, ordered by their popularity + * + * @param int $nr_of_tags number of random tags to be returned + * @param unknown_type $tag_type + * @return mixed an array of tag objects with the following fields: id, name and count + */ +function popular_tags_count($nr_of_tags=20, $tag_type = 'default') { + + global $CFG; + + $query = " + SELECT + tg.rawname, tg.id, tg.name, COUNT(ti.id) AS count, tg.flag + FROM + {$CFG->prefix}tag_instance ti + INNER JOIN + {$CFG->prefix}tag tg + ON + tg.id = ti.tagid + GROUP BY + tg.id, tg.rawname, tg.name, tg.flag + ORDER BY + count + DESC + "; + + return get_records_sql($query,0,$nr_of_tags); + + +} + +function tag_cron(){ + + tag_instance_table_cleanup(); + + if ($tags = get_all_tags('*')) { + + foreach ($tags as $tag){ + cache_correlated_tags($tag->id); + } + } + +} +/*-------------------- Printing functions -------------------- */ + +/** + * Prints a box that contains the management links of a tag + * + * @param $tag_object + * @param $return if true return html string + */ + +function print_tag_management_box($tag_object, $return=false) { + + global $USER, $CFG; + + $tagname = tag_display_name($tag_object); + + $output = ''; + + if (!isguestuser()) { + + $output .= print_box_start('box','tag-management-box', true); + + $systemcontext = get_context_instance(CONTEXT_SYSTEM); + + $links = array(); + + // if the user is not tagged with the $tag_object tag, a link "add blahblah to my interests" will appear + if( !is_item_tagged_with('user', $USER->id, $tag_object->id )) { + $links[] = ''.get_string('addtagtomyinterests','tag',$tagname). ''; + } + + // only people with moodle/tag:edit capability may edit the tag description + if ( has_capability('moodle/tag:edit',$systemcontext) && is_item_tagged_with('user', $USER->id, $tag_object->id ) ) { + $links[] = ''.get_string('edittag', 'tag').''; + } + + // flag as inappropriate link + $links[] = '' . get_string('flagasinappropriate','tag',$tagname). ''; + + // Manage all tags links + if ( has_capability('moodle/tag:manage',$systemcontext) ) { + $links[] = '' . get_string('managetags', 'tag') . '' ; + } + + $output .= implode(' | ', $links); + + $output .= print_box_end(true); + + } + + if ($return) { + return $output; + } else { + echo $output; + } + +} + +/** + * Prints a box with the description of a tag and its related tags + * + * @param unknown_type $tag_object + * @param $return if true return html string + */ + +function print_tag_description_box($tag_object, $return=false) { + + global $USER, $CFG; + + $tagname = tag_display_name($tag_object); + $related_tags = related_tags($tag_object->id); + + $content = !empty($tag_object->description) || $related_tags; + + $output = ''; + + if ($content) { + $output .= print_box_start('generalbox', 'tag-description',true); + } + + if (!empty($tag_object->description)) { + $options = new object(); + $options->para = false; + $output .= format_text($tag_object->description, $tag_object->descriptionformat, $options); + } + + if ($related_tags) { + $output .= '

'.get_string('relatedtags','tag').': ' . tag_links_csv($related_tags); + } + + if ($content) { + $output .= print_box_end(true); + } + + if ($return) { + return $output; + } else { + echo $output; + } +} + +/** + * Prints a table of the users tagged with the tag passed as argument + * + * @param $tag_object + * @param int $users_per_row number of users per row to display + * @param int $limitfrom prints users starting at this point (optional, required if $limitnum is set). + * @param int $limitnum prints this many users (optional, required if $limitfrom is set). + * @param $return if true return html string + */ + +function print_tagged_users_table($tag_object, $limitfrom='' , $limitnum='', $return=false) { + + //List of users with this tag + $userlist = array_values( get_items_tagged_with( + 'user', + $tag_object->id, + 'lastaccess DESC' , + 'id, firstname, lastname, picture', + $limitfrom, + $limitnum) ); + + $output = print_user_list($userlist, true); + + if ($return) { + return $output; + } + else { + echo $output; + } + +} + +/** + * Prints a list of users + * @param array $userlist an array of user objects + * @param $return if true return html string + */ +function print_user_list($userlist, $return=false) { + + $output = ''; + + $output .= '\n"; + + if ($return) { + return $output; + } + else { + echo $output; + } + +} + +/** + * Prints an individual user box + * + * @param $user user object (contains the following fields: id, firstname, lastname and picture) + * @param $return if true return html string + */ +function print_user_box($user, $return=false) { + + global $CFG; + $textlib = textlib_get_instance(); + + $usercontext = get_context_instance(CONTEXT_USER, $user->id); + + $profilelink = ''; + if ( has_capability('moodle/user:viewdetails', $usercontext) ) { + $profilelink = $CFG->wwwroot.'/user/view.php?id='.$user->id; + } + + $output = ''; + + $output .= print_box_start('user-box', 'user'.$user->id, true); + + $fullname = fullname($user); + $alt = ''; + if (!empty($profilelink)) { + $output .= ''; + $alt = $fullname; + } + + //print user image - if image is only content of link it needs ALT text! + if ($user->picture) { + $output .= ''.$alt.''; + } else { + $output .= ''.$alt.''; + } + + $output .= '
'; + + if (!empty($profilelink)) { + $output .= ''; + } + + //truncate name if it's too big + if ($textlib->strlen($fullname) > 26) $fullname = $textlib->substr($fullname,0,26) . '...'; + + $output .= '' . $fullname . ''; + + $output .= print_box_end(true); + + if ($return) { + return $output; + } + else { + echo $output; + } + +} + +/** + * Prints the tag search box + * @param $return if true return html string + * + */ +function print_tag_search_box($return=false) { + + global $CFG; + + $output = ''; + $output .= print_box_start('','tag-search-box', true); + + $output .= '
'; + $output .= '
'; + $output .= ''; + $output .= '
'; + $output .= '
'; + $output .= '
'; + + $output .= print_box_end(true); + + if ($return) { + return $output; + } + else { + echo $output; + } +} + +/** + * Prints the tag search results + * + * @param string $query text that tag names will be matched against + * @param int $page current page + * @param int $perpage nr of users displayed per page + * @param $return if true return html string + */ +function print_tag_search_results($query, $page, $perpage, $return=false) { + + global $CFG, $USER; + + $count = sizeof( search_tags($query,false) ); + $tags = array_values(search_tags($query, true, $page * $perpage , $perpage)); + + $baseurl = $CFG->wwwroot.'/tag/search.php?query=' . $query; + + $output = ''; + + // link "Add $query to my interests" + $addtaglink = ''; + if( !is_item_tagged_with('user', $USER->id, $query )) { + $addtaglink = ''; + $addtaglink .= get_string('addtagtomyinterests','tag',$query). ''; + } + + + if($tags) { // there are results to display!! + + $output .= print_heading(get_string('searchresultsfor', 'tag', $query) . " : {$count}", '', 3, 'main' ,true); + + //print a link "Add $query to my interests" + if (!empty($addtaglink)) { + $output .= print_box($addtaglink,'box','tag-management-box',true); + } + + $nr_of_lis_per_ul = 6; + $nr_of_uls = ceil( sizeof($tags) / $nr_of_lis_per_ul); + + $output .= ''; + $output .= '
 
'; // <-- small layout hack in order to look good in Firefox + + $output .= print_paging_bar($count, $page, $perpage, $baseurl.'&', 'page', false, true); + } + else { //no results were found!! + + $output .= print_heading(get_string('noresultsfor', 'tag', $query), '', 3, 'main' , true); + + //print a link "Add $query to my interests" + if (!empty($addtaglink)) { + $output .= print_box($addtaglink,'box','tag-management-box', true); + } + + } + + if ($return) { + return $output; + } + else { + echo $output; + } + + +} + +/** + * Prints a tag cloud + * + * @param array $tagcloud array of tag objects (fields: id, name, rawname, count and flag) + * @param boolean $shuffle wether or not to shuffle the array passed + * @param int $max_size maximum text size, in percentage + * @param int $min_size minimum text size, in percentage + * @param $return if true return html string + */ +function print_tag_cloud($tagcloud, $shuffle=true, $max_size=180, $min_size=80, $return=false) { + + global $CFG; + + if (empty($tagcloud)) { + return; + } + + if ($shuffle) { + shuffle($tagcloud); + } else { + ksort($tagcloud); + } + + $count = array(); + foreach ($tagcloud as $key => $value){ + if(!empty($value->count)) { + $count[$key] = log10($value->count); + } + else{ + $count[$key] = 0; + } + } + + $max = max($count); + $min = min($count); + + $spread = $max - $min; + if (0 == $spread) { // we don't want to divide by zero + $spread = 1; + } + + $step = ($max_size - $min_size)/($spread); + + $systemcontext = get_context_instance(CONTEXT_SYSTEM); + $can_manage_tags = has_capability('moodle/tag:manage', $systemcontext); + + //prints the tag cloud + $output = ''; + + if ($return) { + return $output; + } else { + echo $output; + } + } ?>