3 * Category objects are immutable, strictly speaking. If you call methods that change the database,
4 * like to refresh link counts, the objects will be appropriately reinitialized.
5 * Member variables are lazy-initialized.
7 * TODO: Move some stuff from CategoryPage.php to here, and use that.
13 /** Name of the category, normalized to DB-key form */
14 private $mName = null;
16 /** Category page title */
17 private $mTitle = null;
18 /** Counts of membership (cat_pages, cat_subcats, cat_files) */
19 private $mPages = null, $mSubcats = null, $mFiles = null;
21 private function __construct() {}
24 * Set up all member variables using a database query.
25 * @return bool True on success, false on failure.
27 protected function initialize() {
28 if ( $this->mName === null && $this->mTitle )
29 $this->mName = $title->getDBKey();
31 if( $this->mName === null && $this->mID === null ) {
32 throw new MWException( __METHOD__.' has both names and IDs null' );
33 } elseif( $this->mID === null ) {
34 $where = array( 'cat_title' => $this->mName );
35 } elseif( $this->mName === null ) {
36 $where = array( 'cat_id' => $this->mID );
41 $dbr = wfGetDB( DB_SLAVE );
42 $row = $dbr->selectRow(
44 array( 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats',
50 # Okay, there were no contents. Nothing to initialize.
51 if ( $this->mTitle ) {
52 # If there is a title object but no record in the category table, treat this as an empty category
54 $this->mName = $this->mTitle->getDBKey();
64 $this->mID = $row->cat_id;
65 $this->mName = $row->cat_title;
66 $this->mPages = $row->cat_pages;
67 $this->mSubcats = $row->cat_subcats;
68 $this->mFiles = $row->cat_files;
70 # (bug 13683) If the count is negative, then 1) it's obviously wrong
71 # and should not be kept, and 2) we *probably* don't have to scan many
72 # rows to obtain the correct figure, so let's risk a one-time recount.
73 if( $this->mPages < 0 || $this->mSubcats < 0 ||
75 $this->refreshCounts();
84 * @param $name Array: A category name (no "Category:" prefix). It need
85 * not be normalized, with spaces replaced by underscores.
86 * @return mixed Category, or false on a totally invalid name
88 public static function newFromName( $name ) {
90 $title = Title::makeTitleSafe( NS_CATEGORY, $name );
91 if( !is_object( $title ) ) {
95 $cat->mTitle = $title;
96 $cat->mName = $title->getDBKey();
104 * @param $title Title for the category page
105 * @return Mixed: category, or false on a totally invalid name
107 public static function newFromTitle( $title ) {
110 $cat->mTitle = $title;
111 $cat->mName = $title->getDBKey();
119 * @param $id Integer: a category id
122 public static function newFromID( $id ) {
124 $cat->mID = intval( $id );
129 * Factory function, for constructing a Category object from a result set
131 * @param $row result set row, must contain the cat_xxx fields. If the fields are null,
132 * the resulting Category object will represent an empty category if a title object
133 * was given. If the fields are null and no title was given, this method fails and returns false.
134 * @param $title optional title object for the category represented by the given row.
135 * May be provided if it is already known, to avoid having to re-create a title object later.
138 public static function newFromRow( $row, $title = null ) {
140 $cat->mTitle = $title;
143 # NOTE: the row often results from a LEFT JOIN on categorylinks. This may result in
144 # all the cat_xxx fields being null, if the category page exists, but nothing
145 # was ever added to the category. This case should be treated linke an empty
146 # category, if possible.
148 if ( $row->cat_title === null ) {
149 if ( $title === null ) {
150 # the name is probably somewhere in the row, for example as page_title,
151 # but we can't know that here...
154 $cat->mName = $title->getDBKey(); # if we have a title object, fetch the category name from there
162 $cat->mName = $row->cat_title;
163 $cat->mID = $row->cat_id;
164 $cat->mSubcats = $row->cat_subcats;
165 $cat->mPages = $row->cat_pages;
166 $cat->mFiles = $row->cat_files;
172 /** @return mixed DB key name, or false on failure */
173 public function getName() { return $this->getX( 'mName' ); }
174 /** @return mixed Category ID, or false on failure */
175 public function getID() { return $this->getX( 'mID' ); }
176 /** @return mixed Total number of member pages, or false on failure */
177 public function getPageCount() { return $this->getX( 'mPages' ); }
178 /** @return mixed Number of subcategories, or false on failure */
179 public function getSubcatCount() { return $this->getX( 'mSubcats' ); }
180 /** @return mixed Number of member files, or false on failure */
181 public function getFileCount() { return $this->getX( 'mFiles' ); }
184 * @return mixed The Title for this category, or false on failure.
186 public function getTitle() {
187 if( $this->mTitle ) return $this->mTitle;
189 if( !$this->initialize() ) {
193 $this->mTitle = Title::makeTitleSafe( NS_CATEGORY, $this->mName );
194 return $this->mTitle;
198 * Fetch a TitleArray of up to $limit category members, beginning after the
199 * category sort key $offset.
200 * @param $limit integer
201 * @param $offset string
202 * @return TitleArray object for category members.
204 public function getMembers( $limit = false, $offset = '' ) {
205 $dbr = wfGetDB( DB_SLAVE );
207 $conds = array( 'cl_to' => $this->getName(), 'cl_from = page_id' );
208 $options = array( 'ORDER BY' => 'cl_sortkey' );
209 if( $limit ) $options[ 'LIMIT' ] = $limit;
210 if( $offset !== '' ) $conds[] = 'cl_sortkey > ' . $dbr->addQuotes( $offset );
212 return TitleArray::newFromResult(
214 array( 'page', 'categorylinks' ),
215 array( 'page_id', 'page_namespace','page_title', 'page_len',
216 'page_is_redirect', 'page_latest' ),
224 /** Generic accessor */
225 private function getX( $key ) {
226 if( !$this->initialize() ) {
229 return $this->{$key};
233 * Refresh the counts for this category.
235 * @return bool True on success, false on failure
237 public function refreshCounts() {
241 $dbw = wfGetDB( DB_MASTER );
243 # Note, we must use names for this, since categorylinks does.
244 if( $this->mName === null ) {
245 if( !$this->initialize() ) {
249 # Let's be sure that the row exists in the table. We don't need to
250 # do this if we got the row from the table in initialization!
253 array( 'cat_title' => $this->mName ),
259 $cond1 = $dbw->conditional( 'page_namespace='.NS_CATEGORY, 1, 'NULL' );
260 $cond2 = $dbw->conditional( 'page_namespace='.NS_FILE, 1, 'NULL' );
261 $result = $dbw->selectRow(
262 array( 'categorylinks', 'page' ),
263 array( 'COUNT(*) AS pages',
264 "COUNT($cond1) AS subcats",
265 "COUNT($cond2) AS files"
267 array( 'cl_to' => $this->mName, 'page_id = cl_from' ),
274 'cat_pages' => $result->pages,
275 'cat_subcats' => $result->subcats,
276 'cat_files' => $result->files
278 array( 'cat_title' => $this->mName ),
283 # Now we should update our local counts.
284 $this->mPages = $result->pages;
285 $this->mSubcats = $result->subcats;
286 $this->mFiles = $result->files;