ApiQueryWatchlist: Handle empty wltypes
[mediawiki.git] / includes / api / ApiQueryBacklinks.php
blob4c323206ef70d49ccc25833fb52d984033699af7
1 <?php
2 /**
5 * Created on Oct 16, 2006
7 * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
22 * http://www.gnu.org/copyleft/gpl.html
24 * @file
27 /**
28 * This is a three-in-one module to query:
29 * * backlinks - links pointing to the given page,
30 * * embeddedin - what pages transclude the given page within themselves,
31 * * imageusage - what pages use the given image
33 * @ingroup API
35 class ApiQueryBacklinks extends ApiQueryGeneratorBase {
37 /**
38 * @var Title
40 private $rootTitle;
42 private $params, $cont, $redirect;
43 private $bl_ns, $bl_from, $bl_from_ns, $bl_table, $bl_code, $bl_title, $bl_fields, $hasNS;
45 /**
46 * Maps ns and title to pageid
48 * @var array
50 private $pageMap = [];
51 private $resultArr;
53 private $redirTitles = [];
54 private $continueStr = null;
56 // output element name, database column field prefix, database table
57 private $backlinksSettings = [
58 'backlinks' => [
59 'code' => 'bl',
60 'prefix' => 'pl',
61 'linktbl' => 'pagelinks',
62 'helpurl' => 'https://www.mediawiki.org/wiki/API:Backlinks',
64 'embeddedin' => [
65 'code' => 'ei',
66 'prefix' => 'tl',
67 'linktbl' => 'templatelinks',
68 'helpurl' => 'https://www.mediawiki.org/wiki/API:Embeddedin',
70 'imageusage' => [
71 'code' => 'iu',
72 'prefix' => 'il',
73 'linktbl' => 'imagelinks',
74 'helpurl' => 'https://www.mediawiki.org/wiki/API:Imageusage',
78 public function __construct( ApiQuery $query, $moduleName ) {
79 $settings = $this->backlinksSettings[$moduleName];
80 $prefix = $settings['prefix'];
81 $code = $settings['code'];
82 $this->resultArr = [];
84 parent::__construct( $query, $moduleName, $code );
85 $this->bl_ns = $prefix . '_namespace';
86 $this->bl_from = $prefix . '_from';
87 $this->bl_from_ns = $prefix . '_from_namespace';
88 $this->bl_table = $settings['linktbl'];
89 $this->bl_code = $code;
90 $this->helpUrl = $settings['helpurl'];
92 $this->hasNS = $moduleName !== 'imageusage';
93 if ( $this->hasNS ) {
94 $this->bl_title = $prefix . '_title';
95 $this->bl_fields = [
96 $this->bl_ns,
97 $this->bl_title
99 } else {
100 $this->bl_title = $prefix . '_to';
101 $this->bl_fields = [
102 $this->bl_title
107 public function execute() {
108 $this->run();
111 public function getCacheMode( $params ) {
112 return 'public';
115 public function executeGenerator( $resultPageSet ) {
116 $this->run( $resultPageSet );
120 * @param ApiPageSet $resultPageSet
121 * @return void
123 private function runFirstQuery( $resultPageSet = null ) {
124 $this->addTables( [ $this->bl_table, 'page' ] );
125 $this->addWhere( "{$this->bl_from}=page_id" );
126 if ( is_null( $resultPageSet ) ) {
127 $this->addFields( [ 'page_id', 'page_title', 'page_namespace' ] );
128 } else {
129 $this->addFields( $resultPageSet->getPageTableFields() );
131 $this->addFields( [ 'page_is_redirect', 'from_ns' => 'page_namespace' ] );
133 $this->addWhereFld( $this->bl_title, $this->rootTitle->getDBkey() );
134 if ( $this->hasNS ) {
135 $this->addWhereFld( $this->bl_ns, $this->rootTitle->getNamespace() );
137 $this->addWhereFld( $this->bl_from_ns, $this->params['namespace'] );
139 if ( count( $this->cont ) >= 2 ) {
140 $op = $this->params['dir'] == 'descending' ? '<' : '>';
141 if ( count( $this->params['namespace'] ) > 1 ) {
142 $this->addWhere(
143 "{$this->bl_from_ns} $op {$this->cont[0]} OR " .
144 "({$this->bl_from_ns} = {$this->cont[0]} AND " .
145 "{$this->bl_from} $op= {$this->cont[1]})"
147 } else {
148 $this->addWhere( "{$this->bl_from} $op= {$this->cont[1]}" );
152 if ( $this->params['filterredir'] == 'redirects' ) {
153 $this->addWhereFld( 'page_is_redirect', 1 );
154 } elseif ( $this->params['filterredir'] == 'nonredirects' && !$this->redirect ) {
155 // bug 22245 - Check for !redirect, as filtering nonredirects, when
156 // getting what links to them is contradictory
157 $this->addWhereFld( 'page_is_redirect', 0 );
160 $this->addOption( 'LIMIT', $this->params['limit'] + 1 );
161 $sort = ( $this->params['dir'] == 'descending' ? ' DESC' : '' );
162 $orderBy = [];
163 if ( count( $this->params['namespace'] ) > 1 ) {
164 $orderBy[] = $this->bl_from_ns . $sort;
166 $orderBy[] = $this->bl_from . $sort;
167 $this->addOption( 'ORDER BY', $orderBy );
168 $this->addOption( 'STRAIGHT_JOIN' );
170 $res = $this->select( __METHOD__ );
171 $count = 0;
172 foreach ( $res as $row ) {
173 if ( ++$count > $this->params['limit'] ) {
174 // We've reached the one extra which shows that there are
175 // additional pages to be had. Stop here...
176 // Continue string may be overridden at a later step
177 $this->continueStr = "{$row->from_ns}|{$row->page_id}";
178 break;
181 // Fill in continuation fields for later steps
182 if ( count( $this->cont ) < 2 ) {
183 $this->cont[] = $row->from_ns;
184 $this->cont[] = $row->page_id;
187 $this->pageMap[$row->page_namespace][$row->page_title] = $row->page_id;
188 $t = Title::makeTitle( $row->page_namespace, $row->page_title );
189 if ( $row->page_is_redirect ) {
190 $this->redirTitles[] = $t;
193 if ( is_null( $resultPageSet ) ) {
194 $a = [ 'pageid' => intval( $row->page_id ) ];
195 ApiQueryBase::addTitleInfo( $a, $t );
196 if ( $row->page_is_redirect ) {
197 $a['redirect'] = true;
199 // Put all the results in an array first
200 $this->resultArr[$a['pageid']] = $a;
201 } else {
202 $resultPageSet->processDbRow( $row );
208 * @param ApiPageSet $resultPageSet
209 * @return void
211 private function runSecondQuery( $resultPageSet = null ) {
212 $db = $this->getDB();
213 $this->addTables( [ 'page', $this->bl_table ] );
214 $this->addWhere( "{$this->bl_from}=page_id" );
216 if ( is_null( $resultPageSet ) ) {
217 $this->addFields( [ 'page_id', 'page_title', 'page_namespace', 'page_is_redirect' ] );
218 } else {
219 $this->addFields( $resultPageSet->getPageTableFields() );
222 $this->addFields( [ $this->bl_title, 'from_ns' => 'page_namespace' ] );
223 if ( $this->hasNS ) {
224 $this->addFields( $this->bl_ns );
227 // We can't use LinkBatch here because $this->hasNS may be false
228 $titleWhere = [];
229 $allRedirNs = [];
230 $allRedirDBkey = [];
231 /** @var $t Title */
232 foreach ( $this->redirTitles as $t ) {
233 $redirNs = $t->getNamespace();
234 $redirDBkey = $t->getDBkey();
235 $titleWhere[] = "{$this->bl_title} = " . $db->addQuotes( $redirDBkey ) .
236 ( $this->hasNS ? " AND {$this->bl_ns} = {$redirNs}" : '' );
237 $allRedirNs[$redirNs] = true;
238 $allRedirDBkey[$redirDBkey] = true;
240 $this->addWhere( $db->makeList( $titleWhere, LIST_OR ) );
241 $this->addWhereFld( 'page_namespace', $this->params['namespace'] );
243 if ( count( $this->cont ) >= 6 ) {
244 $op = $this->params['dir'] == 'descending' ? '<' : '>';
246 $where = "{$this->bl_from} $op= {$this->cont[5]}";
247 // Don't bother with namespace, title, or from_namespace if it's
248 // otherwise constant in the where clause.
249 if ( count( $this->params['namespace'] ) > 1 ) {
250 $where = "{$this->bl_from_ns} $op {$this->cont[4]} OR " .
251 "({$this->bl_from_ns} = {$this->cont[4]} AND ($where))";
253 if ( count( $allRedirDBkey ) > 1 ) {
254 $title = $db->addQuotes( $this->cont[3] );
255 $where = "{$this->bl_title} $op $title OR " .
256 "({$this->bl_title} = $title AND ($where))";
258 if ( $this->hasNS && count( $allRedirNs ) > 1 ) {
259 $where = "{$this->bl_ns} $op {$this->cont[2]} OR " .
260 "({$this->bl_ns} = {$this->cont[2]} AND ($where))";
263 $this->addWhere( $where );
265 if ( $this->params['filterredir'] == 'redirects' ) {
266 $this->addWhereFld( 'page_is_redirect', 1 );
267 } elseif ( $this->params['filterredir'] == 'nonredirects' ) {
268 $this->addWhereFld( 'page_is_redirect', 0 );
271 $this->addOption( 'LIMIT', $this->params['limit'] + 1 );
272 $orderBy = [];
273 $sort = ( $this->params['dir'] == 'descending' ? ' DESC' : '' );
274 // Don't order by namespace/title/from_namespace if it's constant in the WHERE clause
275 if ( $this->hasNS && count( $allRedirNs ) > 1 ) {
276 $orderBy[] = $this->bl_ns . $sort;
278 if ( count( $allRedirDBkey ) > 1 ) {
279 $orderBy[] = $this->bl_title . $sort;
281 if ( count( $this->params['namespace'] ) > 1 ) {
282 $orderBy[] = $this->bl_from_ns . $sort;
284 $orderBy[] = $this->bl_from . $sort;
285 $this->addOption( 'ORDER BY', $orderBy );
286 $this->addOption( 'USE INDEX', [ 'page' => 'PRIMARY' ] );
288 $res = $this->select( __METHOD__ );
289 $count = 0;
290 foreach ( $res as $row ) {
291 $ns = $this->hasNS ? $row->{$this->bl_ns} : NS_FILE;
293 if ( ++$count > $this->params['limit'] ) {
294 // We've reached the one extra which shows that there are
295 // additional pages to be had. Stop here...
296 // Note we must keep the parameters for the first query constant
297 // This may be overridden at a later step
298 $title = $row->{$this->bl_title};
299 $this->continueStr = implode( '|', array_slice( $this->cont, 0, 2 ) ) .
300 "|$ns|$title|{$row->from_ns}|{$row->page_id}";
301 break;
304 // Fill in continuation fields for later steps
305 if ( count( $this->cont ) < 6 ) {
306 $this->cont[] = $ns;
307 $this->cont[] = $row->{$this->bl_title};
308 $this->cont[] = $row->from_ns;
309 $this->cont[] = $row->page_id;
312 if ( is_null( $resultPageSet ) ) {
313 $a['pageid'] = intval( $row->page_id );
314 ApiQueryBase::addTitleInfo( $a, Title::makeTitle( $row->page_namespace, $row->page_title ) );
315 if ( $row->page_is_redirect ) {
316 $a['redirect'] = true;
318 $parentID = $this->pageMap[$ns][$row->{$this->bl_title}];
319 // Put all the results in an array first
320 $this->resultArr[$parentID]['redirlinks'][$row->page_id] = $a;
321 } else {
322 $resultPageSet->processDbRow( $row );
328 * @param ApiPageSet $resultPageSet
329 * @return void
331 private function run( $resultPageSet = null ) {
332 $this->params = $this->extractRequestParams( false );
333 $this->redirect = isset( $this->params['redirect'] ) && $this->params['redirect'];
334 $userMax = ( $this->redirect ? ApiBase::LIMIT_BIG1 / 2 : ApiBase::LIMIT_BIG1 );
335 $botMax = ( $this->redirect ? ApiBase::LIMIT_BIG2 / 2 : ApiBase::LIMIT_BIG2 );
337 $result = $this->getResult();
339 if ( $this->params['limit'] == 'max' ) {
340 $this->params['limit'] = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
341 $result->addParsedLimit( $this->getModuleName(), $this->params['limit'] );
342 } else {
343 $this->params['limit'] = intval( $this->params['limit'] );
344 $this->validateLimit( 'limit', $this->params['limit'], 1, $userMax, $botMax );
347 $this->rootTitle = $this->getTitleOrPageId( $this->params )->getTitle();
349 // only image titles are allowed for the root in imageinfo mode
350 if ( !$this->hasNS && $this->rootTitle->getNamespace() !== NS_FILE ) {
351 $this->dieWithError(
352 [ 'apierror-imageusage-badtitle', $this->getModuleName() ],
353 'bad_image_title'
357 // Parse and validate continuation parameter
358 $this->cont = [];
359 if ( $this->params['continue'] !== null ) {
360 $cont = explode( '|', $this->params['continue'] );
362 switch ( count( $cont ) ) {
363 case 8:
364 // redirect page ID for result adding
365 $this->cont[7] = (int)$cont[7];
366 $this->dieContinueUsageIf( $cont[7] !== (string)$this->cont[7] );
368 /* Fall through */
370 case 7:
371 // top-level page ID for result adding
372 $this->cont[6] = (int)$cont[6];
373 $this->dieContinueUsageIf( $cont[6] !== (string)$this->cont[6] );
375 /* Fall through */
377 case 6:
378 // ns for 2nd query (even for imageusage)
379 $this->cont[2] = (int)$cont[2];
380 $this->dieContinueUsageIf( $cont[2] !== (string)$this->cont[2] );
382 // title for 2nd query
383 $this->cont[3] = $cont[3];
385 // from_ns for 2nd query
386 $this->cont[4] = (int)$cont[4];
387 $this->dieContinueUsageIf( $cont[4] !== (string)$this->cont[4] );
389 // from_id for 1st query
390 $this->cont[5] = (int)$cont[5];
391 $this->dieContinueUsageIf( $cont[5] !== (string)$this->cont[5] );
393 /* Fall through */
395 case 2:
396 // from_ns for 1st query
397 $this->cont[0] = (int)$cont[0];
398 $this->dieContinueUsageIf( $cont[0] !== (string)$this->cont[0] );
400 // from_id for 1st query
401 $this->cont[1] = (int)$cont[1];
402 $this->dieContinueUsageIf( $cont[1] !== (string)$this->cont[1] );
404 break;
406 default:
407 $this->dieContinueUsageIf( true );
410 ksort( $this->cont );
413 $this->runFirstQuery( $resultPageSet );
414 if ( $this->redirect && count( $this->redirTitles ) ) {
415 $this->resetQueryParams();
416 $this->runSecondQuery( $resultPageSet );
419 // Fill in any missing fields in case it's needed below
420 $this->cont += [ 0, 0, 0, '', 0, 0, 0 ];
422 if ( is_null( $resultPageSet ) ) {
423 // Try to add the result data in one go and pray that it fits
424 $code = $this->bl_code;
425 $data = array_map( function ( $arr ) use ( $result, $code ) {
426 if ( isset( $arr['redirlinks'] ) ) {
427 $arr['redirlinks'] = array_values( $arr['redirlinks'] );
428 ApiResult::setIndexedTagName( $arr['redirlinks'], $code );
430 return $arr;
431 }, array_values( $this->resultArr ) );
432 $fit = $result->addValue( 'query', $this->getModuleName(), $data );
433 if ( !$fit ) {
434 // It didn't fit. Add elements one by one until the
435 // result is full.
436 ksort( $this->resultArr );
437 if ( count( $this->cont ) >= 7 ) {
438 $startAt = $this->cont[6];
439 } else {
440 reset( $this->resultArr );
441 $startAt = key( $this->resultArr );
443 $idx = 0;
444 foreach ( $this->resultArr as $pageID => $arr ) {
445 if ( $pageID < $startAt ) {
446 continue;
449 // Add the basic entry without redirlinks first
450 $fit = $result->addValue(
451 [ 'query', $this->getModuleName() ],
452 $idx, array_diff_key( $arr, [ 'redirlinks' => '' ] ) );
453 if ( !$fit ) {
454 $this->continueStr = implode( '|', array_slice( $this->cont, 0, 6 ) ) .
455 "|$pageID";
456 break;
459 $hasRedirs = false;
460 $redirLinks = isset( $arr['redirlinks'] ) ? (array)$arr['redirlinks'] : [];
461 ksort( $redirLinks );
462 if ( count( $this->cont ) >= 8 && $pageID == $startAt ) {
463 $redirStartAt = $this->cont[7];
464 } else {
465 reset( $redirLinks );
466 $redirStartAt = key( $redirLinks );
468 foreach ( $redirLinks as $key => $redir ) {
469 if ( $key < $redirStartAt ) {
470 continue;
473 $fit = $result->addValue(
474 [ 'query', $this->getModuleName(), $idx, 'redirlinks' ],
475 null, $redir );
476 if ( !$fit ) {
477 $this->continueStr = implode( '|', array_slice( $this->cont, 0, 6 ) ) .
478 "|$pageID|$key";
479 break;
481 $hasRedirs = true;
483 if ( $hasRedirs ) {
484 $result->addIndexedTagName(
485 [ 'query', $this->getModuleName(), $idx, 'redirlinks' ],
486 $this->bl_code );
488 if ( !$fit ) {
489 break;
492 $idx++;
496 $result->addIndexedTagName(
497 [ 'query', $this->getModuleName() ],
498 $this->bl_code
501 if ( !is_null( $this->continueStr ) ) {
502 $this->setContinueEnumParameter( 'continue', $this->continueStr );
506 public function getAllowedParams() {
507 $retval = [
508 'title' => [
509 ApiBase::PARAM_TYPE => 'string',
511 'pageid' => [
512 ApiBase::PARAM_TYPE => 'integer',
514 'continue' => [
515 ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
517 'namespace' => [
518 ApiBase::PARAM_ISMULTI => true,
519 ApiBase::PARAM_TYPE => 'namespace'
521 'dir' => [
522 ApiBase::PARAM_DFLT => 'ascending',
523 ApiBase::PARAM_TYPE => [
524 'ascending',
525 'descending'
528 'filterredir' => [
529 ApiBase::PARAM_DFLT => 'all',
530 ApiBase::PARAM_TYPE => [
531 'all',
532 'redirects',
533 'nonredirects'
536 'limit' => [
537 ApiBase::PARAM_DFLT => 10,
538 ApiBase::PARAM_TYPE => 'limit',
539 ApiBase::PARAM_MIN => 1,
540 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
541 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
544 if ( $this->getModuleName() == 'embeddedin' ) {
545 return $retval;
547 $retval['redirect'] = false;
549 return $retval;
552 protected function getExamplesMessages() {
553 static $examples = [
554 'backlinks' => [
555 'action=query&list=backlinks&bltitle=Main%20Page'
556 => 'apihelp-query+backlinks-example-simple',
557 'action=query&generator=backlinks&gbltitle=Main%20Page&prop=info'
558 => 'apihelp-query+backlinks-example-generator',
560 'embeddedin' => [
561 'action=query&list=embeddedin&eititle=Template:Stub'
562 => 'apihelp-query+embeddedin-example-simple',
563 'action=query&generator=embeddedin&geititle=Template:Stub&prop=info'
564 => 'apihelp-query+embeddedin-example-generator',
566 'imageusage' => [
567 'action=query&list=imageusage&iutitle=File:Albert%20Einstein%20Head.jpg'
568 => 'apihelp-query+imageusage-example-simple',
569 'action=query&generator=imageusage&giutitle=File:Albert%20Einstein%20Head.jpg&prop=info'
570 => 'apihelp-query+imageusage-example-generator',
574 return $examples[$this->getModuleName()];
577 public function getHelpUrls() {
578 return $this->helpUrl;