3 * Representation for a category.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
25 * Category objects are immutable, strictly speaking. If you call methods that change the database,
26 * like to refresh link counts, the objects will be appropriately reinitialized.
27 * Member variables are lazy-initialized.
29 * @todo Move some stuff from CategoryPage.php to here, and use that.
32 /** Name of the category, normalized to DB-key form */
33 private $mName = null;
39 private $mTitle = null;
40 /** Counts of membership (cat_pages, cat_subcats, cat_files) */
41 private $mPages = null, $mSubcats = null, $mFiles = null;
43 private function __construct() {
47 * Set up all member variables using a database query.
49 * @return bool True on success, false on failure.
51 protected function initialize() {
52 if ( $this->mName
=== null && $this->mID
=== null ) {
53 throw new MWException( __METHOD__
. ' has both names and IDs null' );
54 } elseif ( $this->mID
=== null ) {
55 $where = array( 'cat_title' => $this->mName
);
56 } elseif ( $this->mName
=== null ) {
57 $where = array( 'cat_id' => $this->mID
);
63 wfProfileIn( __METHOD__
);
65 $dbr = wfGetDB( DB_SLAVE
);
66 $row = $dbr->selectRow(
68 array( 'cat_id', 'cat_title', 'cat_pages', 'cat_subcats', 'cat_files' ),
73 wfProfileOut( __METHOD__
);
76 # Okay, there were no contents. Nothing to initialize.
77 if ( $this->mTitle
) {
78 # If there is a title object but no record in the category table,
79 # treat this as an empty category.
81 $this->mName
= $this->mTitle
->getDBkey();
92 $this->mID
= $row->cat_id
;
93 $this->mName
= $row->cat_title
;
94 $this->mPages
= $row->cat_pages
;
95 $this->mSubcats
= $row->cat_subcats
;
96 $this->mFiles
= $row->cat_files
;
98 # (bug 13683) If the count is negative, then 1) it's obviously wrong
99 # and should not be kept, and 2) we *probably* don't have to scan many
100 # rows to obtain the correct figure, so let's risk a one-time recount.
101 if ( $this->mPages
< 0 ||
$this->mSubcats
< 0 ||
$this->mFiles
< 0 ) {
102 $this->refreshCounts();
111 * @param array $name A category name (no "Category:" prefix). It need
112 * not be normalized, with spaces replaced by underscores.
113 * @return mixed Category, or false on a totally invalid name
115 public static function newFromName( $name ) {
117 $title = Title
::makeTitleSafe( NS_CATEGORY
, $name );
119 if ( !is_object( $title ) ) {
123 $cat->mTitle
= $title;
124 $cat->mName
= $title->getDBkey();
132 * @param Title $title Title for the category page
133 * @return Category|bool On a totally invalid name
135 public static function newFromTitle( $title ) {
138 $cat->mTitle
= $title;
139 $cat->mName
= $title->getDBkey();
147 * @param int $id A category id
150 public static function newFromID( $id ) {
152 $cat->mID
= intval( $id );
157 * Factory function, for constructing a Category object from a result set
159 * @param object $row Result set row, must contain the cat_xxx fields. If the
160 * fields are null, the resulting Category object will represent an empty
161 * category if a title object was given. If the fields are null and no
162 * title was given, this method fails and returns false.
163 * @param Title $title Optional title object for the category represented by
164 * the given row. May be provided if it is already known, to avoid having
165 * to re-create a title object later.
168 public static function newFromRow( $row, $title = null ) {
170 $cat->mTitle
= $title;
172 # NOTE: the row often results from a LEFT JOIN on categorylinks. This may result in
173 # all the cat_xxx fields being null, if the category page exists, but nothing
174 # was ever added to the category. This case should be treated link an empty
175 # category, if possible.
177 if ( $row->cat_title
=== null ) {
178 if ( $title === null ) {
179 # the name is probably somewhere in the row, for example as page_title,
180 # but we can't know that here...
183 # if we have a title object, fetch the category name from there
184 $cat->mName
= $title->getDBkey();
192 $cat->mName
= $row->cat_title
;
193 $cat->mID
= $row->cat_id
;
194 $cat->mSubcats
= $row->cat_subcats
;
195 $cat->mPages
= $row->cat_pages
;
196 $cat->mFiles
= $row->cat_files
;
203 * @return mixed DB key name, or false on failure
205 public function getName() {
206 return $this->getX( 'mName' );
210 * @return mixed Category ID, or false on failure
212 public function getID() {
213 return $this->getX( 'mID' );
217 * @return mixed Total number of member pages, or false on failure
219 public function getPageCount() {
220 return $this->getX( 'mPages' );
224 * @return mixed Number of subcategories, or false on failure
226 public function getSubcatCount() {
227 return $this->getX( 'mSubcats' );
231 * @return mixed Number of member files, or false on failure
233 public function getFileCount() {
234 return $this->getX( 'mFiles' );
238 * @return Title|bool Title for this category, or false on failure.
240 public function getTitle() {
241 if ( $this->mTitle
) {
242 return $this->mTitle
;
245 if ( !$this->initialize() ) {
249 $this->mTitle
= Title
::makeTitleSafe( NS_CATEGORY
, $this->mName
);
250 return $this->mTitle
;
254 * Fetch a TitleArray of up to $limit category members, beginning after the
255 * category sort key $offset.
257 * @param string $offset
258 * @return TitleArray TitleArray object for category members.
260 public function getMembers( $limit = false, $offset = '' ) {
261 wfProfileIn( __METHOD__
);
263 $dbr = wfGetDB( DB_SLAVE
);
265 $conds = array( 'cl_to' => $this->getName(), 'cl_from = page_id' );
266 $options = array( 'ORDER BY' => 'cl_sortkey' );
269 $options['LIMIT'] = $limit;
272 if ( $offset !== '' ) {
273 $conds[] = 'cl_sortkey > ' . $dbr->addQuotes( $offset );
276 $result = TitleArray
::newFromResult(
278 array( 'page', 'categorylinks' ),
279 array( 'page_id', 'page_namespace', 'page_title', 'page_len',
280 'page_is_redirect', 'page_latest' ),
287 wfProfileOut( __METHOD__
);
296 private function getX( $key ) {
297 if ( !$this->initialize() ) {
300 return $this->{$key};
304 * Refresh the counts for this category.
306 * @return bool True on success, false on failure
308 public function refreshCounts() {
309 if ( wfReadOnly() ) {
313 # Note, we must use names for this, since categorylinks does.
314 if ( $this->mName
=== null ) {
315 if ( !$this->initialize() ) {
320 wfProfileIn( __METHOD__
);
322 $dbw = wfGetDB( DB_MASTER
);
323 $dbw->begin( __METHOD__
);
325 # Insert the row if it doesn't exist yet (e.g., this is being run via
326 # update.php from a pre-1.16 schema). TODO: This will cause lots and
327 # lots of gaps on some non-MySQL DBMSes if you run populateCategory.php
328 # repeatedly. Plus it's an extra query that's unneeded almost all the
329 # time. This should be rewritten somehow, probably.
330 $seqVal = $dbw->nextSequenceValue( 'category_cat_id_seq' );
335 'cat_title' => $this->mName
341 $cond1 = $dbw->conditional( array( 'page_namespace' => NS_CATEGORY
), 1, 'NULL' );
342 $cond2 = $dbw->conditional( array( 'page_namespace' => NS_FILE
), 1, 'NULL' );
343 $result = $dbw->selectRow(
344 array( 'categorylinks', 'page' ),
345 array( 'pages' => 'COUNT(*)',
346 'subcats' => "COUNT($cond1)",
347 'files' => "COUNT($cond2)"
349 array( 'cl_to' => $this->mName
, 'page_id = cl_from' ),
351 array( 'LOCK IN SHARE MODE' )
356 'cat_pages' => $result->pages
,
357 'cat_subcats' => $result->subcats
,
358 'cat_files' => $result->files
360 array( 'cat_title' => $this->mName
),
363 $dbw->commit( __METHOD__
);
365 wfProfileOut( __METHOD__
);
367 # Now we should update our local counts.
368 $this->mPages
= $result->pages
;
369 $this->mSubcats
= $result->subcats
;
370 $this->mFiles
= $result->files
;