MediaWiki  master
ApiQueryBacklinks.php
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1 <?php
32 
36  private $rootTitle;
37 
38  private $params;
40  private $cont;
41  private $redirect;
43 
45  private $helpUrl;
46 
52  private $pageMap = [];
53  private $resultArr;
54 
55  private $redirTitles = [];
56  private $continueStr = null;
57 
58  // output element name, database column field prefix, database table
59  private $backlinksSettings = [
60  'backlinks' => [
61  'code' => 'bl',
62  'prefix' => 'pl',
63  'linktbl' => 'pagelinks',
64  'helpurl' => 'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Backlinks',
65  ],
66  'embeddedin' => [
67  'code' => 'ei',
68  'prefix' => 'tl',
69  'linktbl' => 'templatelinks',
70  'helpurl' => 'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Embeddedin',
71  ],
72  'imageusage' => [
73  'code' => 'iu',
74  'prefix' => 'il',
75  'linktbl' => 'imagelinks',
76  'helpurl' => 'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Imageusage',
77  ]
78  ];
79 
80  public function __construct( ApiQuery $query, $moduleName ) {
81  $settings = $this->backlinksSettings[$moduleName];
82  $prefix = $settings['prefix'];
83  $code = $settings['code'];
84  $this->resultArr = [];
85 
86  parent::__construct( $query, $moduleName, $code );
87  $this->bl_ns = $prefix . '_namespace';
88  $this->bl_from = $prefix . '_from';
89  $this->bl_from_ns = $prefix . '_from_namespace';
90  $this->bl_table = $settings['linktbl'];
91  $this->bl_code = $code;
92  $this->helpUrl = $settings['helpurl'];
93 
94  $this->hasNS = $moduleName !== 'imageusage';
95  if ( $this->hasNS ) {
96  $this->bl_title = $prefix . '_title';
97  $this->bl_fields = [
100  ];
101  } else {
102  $this->bl_title = $prefix . '_to';
103  $this->bl_fields = [
105  ];
106  }
107  }
108 
109  public function execute() {
110  $this->run();
111  }
112 
113  public function getCacheMode( $params ) {
114  return 'public';
115  }
116 
117  public function executeGenerator( $resultPageSet ) {
118  $this->run( $resultPageSet );
119  }
120 
125  private function runFirstQuery( $resultPageSet = null ) {
126  $this->addTables( [ $this->bl_table, 'page' ] );
127  $this->addWhere( "{$this->bl_from}=page_id" );
128  if ( is_null( $resultPageSet ) ) {
129  $this->addFields( [ 'page_id', 'page_title', 'page_namespace' ] );
130  } else {
131  $this->addFields( $resultPageSet->getPageTableFields() );
132  }
133  $this->addFields( [ 'page_is_redirect', 'from_ns' => 'page_namespace' ] );
134 
135  $this->addWhereFld( $this->bl_title, $this->rootTitle->getDBkey() );
136  if ( $this->hasNS ) {
137  $this->addWhereFld( $this->bl_ns, $this->rootTitle->getNamespace() );
138  }
139  $this->addWhereFld( $this->bl_from_ns, $this->params['namespace'] );
140 
141  if ( count( $this->cont ) >= 2 ) {
142  $op = $this->params['dir'] == 'descending' ? '<' : '>';
143  if ( $this->params['namespace'] !== null && count( $this->params['namespace'] ) > 1 ) {
144  $this->addWhere(
145  "{$this->bl_from_ns} $op {$this->cont[0]} OR " .
146  "({$this->bl_from_ns} = {$this->cont[0]} AND " .
147  "{$this->bl_from} $op= {$this->cont[1]})"
148  );
149  } else {
150  $this->addWhere( "{$this->bl_from} $op= {$this->cont[1]}" );
151  }
152  }
153 
154  if ( $this->params['filterredir'] == 'redirects' ) {
155  $this->addWhereFld( 'page_is_redirect', 1 );
156  } elseif ( $this->params['filterredir'] == 'nonredirects' && !$this->redirect ) {
157  // T24245 - Check for !redirect, as filtering nonredirects, when
158  // getting what links to them is contradictory
159  $this->addWhereFld( 'page_is_redirect', 0 );
160  }
161 
162  $this->addOption( 'LIMIT', $this->params['limit'] + 1 );
163  $sort = ( $this->params['dir'] == 'descending' ? ' DESC' : '' );
164  $orderBy = [];
165  if ( $this->params['namespace'] !== null && count( $this->params['namespace'] ) > 1 ) {
166  $orderBy[] = $this->bl_from_ns . $sort;
167  }
168  $orderBy[] = $this->bl_from . $sort;
169  $this->addOption( 'ORDER BY', $orderBy );
170  $this->addOption( 'STRAIGHT_JOIN' );
171 
172  $res = $this->select( __METHOD__ );
173  $count = 0;
174  foreach ( $res as $row ) {
175  if ( ++$count > $this->params['limit'] ) {
176  // We've reached the one extra which shows that there are
177  // additional pages to be had. Stop here...
178  // Continue string may be overridden at a later step
179  $this->continueStr = "{$row->from_ns}|{$row->page_id}";
180  break;
181  }
182 
183  // Fill in continuation fields for later steps
184  if ( count( $this->cont ) < 2 ) {
185  $this->cont[] = $row->from_ns;
186  $this->cont[] = $row->page_id;
187  }
188 
189  $this->pageMap[$row->page_namespace][$row->page_title] = $row->page_id;
190  $t = Title::makeTitle( $row->page_namespace, $row->page_title );
191  if ( $row->page_is_redirect ) {
192  $this->redirTitles[] = $t;
193  }
194 
195  if ( is_null( $resultPageSet ) ) {
196  $a = [ 'pageid' => (int)$row->page_id ];
198  if ( $row->page_is_redirect ) {
199  $a['redirect'] = true;
200  }
201  // Put all the results in an array first
202  $this->resultArr[$a['pageid']] = $a;
203  } else {
204  $resultPageSet->processDbRow( $row );
205  }
206  }
207  }
208 
213  private function runSecondQuery( $resultPageSet = null ) {
214  $db = $this->getDB();
215  $this->addTables( [ 'page', $this->bl_table ] );
216  $this->addWhere( "{$this->bl_from}=page_id" );
217 
218  if ( is_null( $resultPageSet ) ) {
219  $this->addFields( [ 'page_id', 'page_title', 'page_namespace', 'page_is_redirect' ] );
220  } else {
221  $this->addFields( $resultPageSet->getPageTableFields() );
222  }
223 
224  $this->addFields( [ $this->bl_title, 'from_ns' => 'page_namespace' ] );
225  if ( $this->hasNS ) {
226  $this->addFields( $this->bl_ns );
227  }
228 
229  // We can't use LinkBatch here because $this->hasNS may be false
230  $titleWhere = [];
231  $allRedirNs = [];
232  $allRedirDBkey = [];
234  foreach ( $this->redirTitles as $t ) {
235  $redirNs = $t->getNamespace();
236  $redirDBkey = $t->getDBkey();
237  $titleWhere[] = "{$this->bl_title} = " . $db->addQuotes( $redirDBkey ) .
238  ( $this->hasNS ? " AND {$this->bl_ns} = {$redirNs}" : '' );
239  $allRedirNs[$redirNs] = true;
240  $allRedirDBkey[$redirDBkey] = true;
241  }
242  $this->addWhere( $db->makeList( $titleWhere, LIST_OR ) );
243  $this->addWhereFld( 'page_namespace', $this->params['namespace'] );
244 
245  if ( count( $this->cont ) >= 6 ) {
246  $op = $this->params['dir'] == 'descending' ? '<' : '>';
247 
248  $where = "{$this->bl_from} $op= {$this->cont[5]}";
249  // Don't bother with namespace, title, or from_namespace if it's
250  // otherwise constant in the where clause.
251  if ( $this->params['namespace'] !== null && count( $this->params['namespace'] ) > 1 ) {
252  $where = "{$this->bl_from_ns} $op {$this->cont[4]} OR " .
253  "({$this->bl_from_ns} = {$this->cont[4]} AND ($where))";
254  }
255  if ( count( $allRedirDBkey ) > 1 ) {
256  $title = $db->addQuotes( $this->cont[3] );
257  $where = "{$this->bl_title} $op $title OR " .
258  "({$this->bl_title} = $title AND ($where))";
259  }
260  if ( $this->hasNS && count( $allRedirNs ) > 1 ) {
261  $where = "{$this->bl_ns} $op {$this->cont[2]} OR " .
262  "({$this->bl_ns} = {$this->cont[2]} AND ($where))";
263  }
264 
265  $this->addWhere( $where );
266  }
267  if ( $this->params['filterredir'] == 'redirects' ) {
268  $this->addWhereFld( 'page_is_redirect', 1 );
269  } elseif ( $this->params['filterredir'] == 'nonredirects' ) {
270  $this->addWhereFld( 'page_is_redirect', 0 );
271  }
272 
273  $this->addOption( 'LIMIT', $this->params['limit'] + 1 );
274  $orderBy = [];
275  $sort = ( $this->params['dir'] == 'descending' ? ' DESC' : '' );
276  // Don't order by namespace/title/from_namespace if it's constant in the WHERE clause
277  if ( $this->hasNS && count( $allRedirNs ) > 1 ) {
278  $orderBy[] = $this->bl_ns . $sort;
279  }
280  if ( count( $allRedirDBkey ) > 1 ) {
281  $orderBy[] = $this->bl_title . $sort;
282  }
283  if ( $this->params['namespace'] !== null && count( $this->params['namespace'] ) > 1 ) {
284  $orderBy[] = $this->bl_from_ns . $sort;
285  }
286  $orderBy[] = $this->bl_from . $sort;
287  $this->addOption( 'ORDER BY', $orderBy );
288  $this->addOption( 'USE INDEX', [ 'page' => 'PRIMARY' ] );
289 
290  $res = $this->select( __METHOD__ );
291  $count = 0;
292  foreach ( $res as $row ) {
293  $ns = $this->hasNS ? $row->{$this->bl_ns} : NS_FILE;
294 
295  if ( ++$count > $this->params['limit'] ) {
296  // We've reached the one extra which shows that there are
297  // additional pages to be had. Stop here...
298  // Note we must keep the parameters for the first query constant
299  // This may be overridden at a later step
300  $title = $row->{$this->bl_title};
301  $this->continueStr = implode( '|', array_slice( $this->cont, 0, 2 ) ) .
302  "|$ns|$title|{$row->from_ns}|{$row->page_id}";
303  break;
304  }
305 
306  // Fill in continuation fields for later steps
307  if ( count( $this->cont ) < 6 ) {
308  $this->cont[] = $ns;
309  $this->cont[] = $row->{$this->bl_title};
310  $this->cont[] = $row->from_ns;
311  $this->cont[] = $row->page_id;
312  }
313 
314  if ( is_null( $resultPageSet ) ) {
315  $a = [ 'pageid' => (int)$row->page_id ];
316  ApiQueryBase::addTitleInfo( $a, Title::makeTitle( $row->page_namespace, $row->page_title ) );
317  if ( $row->page_is_redirect ) {
318  $a['redirect'] = true;
319  }
320  $parentID = $this->pageMap[$ns][$row->{$this->bl_title}];
321  // Put all the results in an array first
322  $this->resultArr[$parentID]['redirlinks'][$row->page_id] = $a;
323  } else {
324  $resultPageSet->processDbRow( $row );
325  }
326  }
327  }
328 
333  private function run( $resultPageSet = null ) {
334  $this->params = $this->extractRequestParams( false );
335  $this->redirect = isset( $this->params['redirect'] ) && $this->params['redirect'];
336  $userMax = ( $this->redirect ? ApiBase::LIMIT_BIG1 / 2 : ApiBase::LIMIT_BIG1 );
337  $botMax = ( $this->redirect ? ApiBase::LIMIT_BIG2 / 2 : ApiBase::LIMIT_BIG2 );
338 
339  $result = $this->getResult();
340 
341  if ( $this->params['limit'] == 'max' ) {
342  $this->params['limit'] = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
343  $result->addParsedLimit( $this->getModuleName(), $this->params['limit'] );
344  } else {
345  $this->params['limit'] = (int)$this->params['limit'];
346  $this->validateLimit( 'limit', $this->params['limit'], 1, $userMax, $botMax );
347  }
348 
349  $this->rootTitle = $this->getTitleFromTitleOrPageId( $this->params );
350 
351  // only image titles are allowed for the root in imageinfo mode
352  if ( !$this->hasNS && $this->rootTitle->getNamespace() !== NS_FILE ) {
353  $this->dieWithError(
354  [ 'apierror-imageusage-badtitle', $this->getModuleName() ],
355  'bad_image_title'
356  );
357  }
358 
359  // Parse and validate continuation parameter
360  $this->cont = [];
361  if ( $this->params['continue'] !== null ) {
362  $cont = explode( '|', $this->params['continue'] );
363 
364  switch ( count( $cont ) ) {
365  case 8:
366  // redirect page ID for result adding
367  $this->cont[7] = (int)$cont[7];
368  $this->dieContinueUsageIf( $cont[7] !== (string)$this->cont[7] );
369 
370  /* Fall through */
371 
372  case 7:
373  // top-level page ID for result adding
374  $this->cont[6] = (int)$cont[6];
375  $this->dieContinueUsageIf( $cont[6] !== (string)$this->cont[6] );
376 
377  /* Fall through */
378 
379  case 6:
380  // ns for 2nd query (even for imageusage)
381  $this->cont[2] = (int)$cont[2];
382  $this->dieContinueUsageIf( $cont[2] !== (string)$this->cont[2] );
383 
384  // title for 2nd query
385  $this->cont[3] = $cont[3];
386 
387  // from_ns for 2nd query
388  $this->cont[4] = (int)$cont[4];
389  $this->dieContinueUsageIf( $cont[4] !== (string)$this->cont[4] );
390 
391  // from_id for 1st query
392  $this->cont[5] = (int)$cont[5];
393  $this->dieContinueUsageIf( $cont[5] !== (string)$this->cont[5] );
394 
395  /* Fall through */
396 
397  case 2:
398  // from_ns for 1st query
399  $this->cont[0] = (int)$cont[0];
400  $this->dieContinueUsageIf( $cont[0] !== (string)$this->cont[0] );
401 
402  // from_id for 1st query
403  $this->cont[1] = (int)$cont[1];
404  $this->dieContinueUsageIf( $cont[1] !== (string)$this->cont[1] );
405 
406  break;
407 
408  default:
409  $this->dieContinueUsageIf( true );
410  }
411 
412  ksort( $this->cont );
413  }
414 
415  $this->runFirstQuery( $resultPageSet );
416  if ( $this->redirect && count( $this->redirTitles ) ) {
417  $this->resetQueryParams();
418  $this->runSecondQuery( $resultPageSet );
419  }
420 
421  // Fill in any missing fields in case it's needed below
422  $this->cont += [ 0, 0, 0, '', 0, 0, 0 ];
423 
424  if ( is_null( $resultPageSet ) ) {
425  // Try to add the result data in one go and pray that it fits
426  $code = $this->bl_code;
427  $data = array_map( function ( $arr ) use ( $code ) {
428  if ( isset( $arr['redirlinks'] ) ) {
429  $arr['redirlinks'] = array_values( $arr['redirlinks'] );
430  ApiResult::setIndexedTagName( $arr['redirlinks'], $code );
431  }
432  return $arr;
433  }, array_values( $this->resultArr ) );
434  $fit = $result->addValue( 'query', $this->getModuleName(), $data );
435  if ( !$fit ) {
436  // It didn't fit. Add elements one by one until the
437  // result is full.
438  ksort( $this->resultArr );
439  if ( count( $this->cont ) >= 7 ) {
440  $startAt = $this->cont[6];
441  } else {
442  reset( $this->resultArr );
443  $startAt = key( $this->resultArr );
444  }
445  $idx = 0;
446  foreach ( $this->resultArr as $pageID => $arr ) {
447  if ( $pageID < $startAt ) {
448  continue;
449  }
450 
451  // Add the basic entry without redirlinks first
452  $fit = $result->addValue(
453  [ 'query', $this->getModuleName() ],
454  $idx, array_diff_key( $arr, [ 'redirlinks' => '' ] ) );
455  if ( !$fit ) {
456  $this->continueStr = implode( '|', array_slice( $this->cont, 0, 6 ) ) .
457  "|$pageID";
458  break;
459  }
460 
461  $hasRedirs = false;
462  $redirLinks = isset( $arr['redirlinks'] ) ? (array)$arr['redirlinks'] : [];
463  ksort( $redirLinks );
464  if ( count( $this->cont ) >= 8 && $pageID == $startAt ) {
465  $redirStartAt = $this->cont[7];
466  } else {
467  reset( $redirLinks );
468  $redirStartAt = key( $redirLinks );
469  }
470  foreach ( $redirLinks as $key => $redir ) {
471  if ( $key < $redirStartAt ) {
472  continue;
473  }
474 
475  $fit = $result->addValue(
476  [ 'query', $this->getModuleName(), $idx, 'redirlinks' ],
477  null, $redir );
478  if ( !$fit ) {
479  $this->continueStr = implode( '|', array_slice( $this->cont, 0, 6 ) ) .
480  "|$pageID|$key";
481  break;
482  }
483  $hasRedirs = true;
484  }
485  if ( $hasRedirs ) {
486  $result->addIndexedTagName(
487  [ 'query', $this->getModuleName(), $idx, 'redirlinks' ],
488  $this->bl_code );
489  }
490  if ( !$fit ) {
491  break;
492  }
493 
494  $idx++;
495  }
496  }
497 
498  $result->addIndexedTagName(
499  [ 'query', $this->getModuleName() ],
500  $this->bl_code
501  );
502  }
503  if ( !is_null( $this->continueStr ) ) {
504  $this->setContinueEnumParameter( 'continue', $this->continueStr );
505  }
506  }
507 
508  public function getAllowedParams() {
509  $retval = [
510  'title' => [
511  ApiBase::PARAM_TYPE => 'string',
512  ],
513  'pageid' => [
514  ApiBase::PARAM_TYPE => 'integer',
515  ],
516  'continue' => [
517  ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
518  ],
519  'namespace' => [
520  ApiBase::PARAM_ISMULTI => true,
521  ApiBase::PARAM_TYPE => 'namespace'
522  ],
523  'dir' => [
524  ApiBase::PARAM_DFLT => 'ascending',
526  'ascending',
527  'descending'
528  ]
529  ],
530  'filterredir' => [
531  ApiBase::PARAM_DFLT => 'all',
533  'all',
534  'redirects',
535  'nonredirects'
536  ]
537  ],
538  'limit' => [
539  ApiBase::PARAM_DFLT => 10,
540  ApiBase::PARAM_TYPE => 'limit',
541  ApiBase::PARAM_MIN => 1,
544  ]
545  ];
546  if ( $this->getModuleName() == 'embeddedin' ) {
547  return $retval;
548  }
549  $retval['redirect'] = false;
550 
551  return $retval;
552  }
553 
554  protected function getExamplesMessages() {
555  static $examples = [
556  'backlinks' => [
557  'action=query&list=backlinks&bltitle=Main%20Page'
558  => 'apihelp-query+backlinks-example-simple',
559  'action=query&generator=backlinks&gbltitle=Main%20Page&prop=info'
560  => 'apihelp-query+backlinks-example-generator',
561  ],
562  'embeddedin' => [
563  'action=query&list=embeddedin&eititle=Template:Stub'
564  => 'apihelp-query+embeddedin-example-simple',
565  'action=query&generator=embeddedin&geititle=Template:Stub&prop=info'
566  => 'apihelp-query+embeddedin-example-generator',
567  ],
568  'imageusage' => [
569  'action=query&list=imageusage&iutitle=File:Albert%20Einstein%20Head.jpg'
570  => 'apihelp-query+imageusage-example-simple',
571  'action=query&generator=imageusage&giutitle=File:Albert%20Einstein%20Head.jpg&prop=info'
572  => 'apihelp-query+imageusage-example-generator',
573  ]
574  ];
575 
576  return $examples[$this->getModuleName()];
577  }
578 
579  public function getHelpUrls() {
580  return $this->helpUrl;
581  }
582 }
select( $method, $extraQuery=[], array &$hookData=null)
Execute a SELECT query based on the values in the internal arrays.
getTitleFromTitleOrPageId( $params)
Get a Title object from a title or pageid param, if possible.
Definition: ApiBase.php:1062
const PARAM_TYPE
(string|string[]) Either an array of allowed value strings, or a string type as described below...
Definition: ApiBase.php:94
getDB()
Get the Query database connection (read-only)
const LIMIT_BIG2
Fast query, apihighlimits limit.
Definition: ApiBase.php:261
static addTitleInfo(&$arr, $title, $prefix='')
Add information (title and namespace) about a Title object to a result array.
getResult()
Get the result object.
Definition: ApiBase.php:640
validateLimit( $paramName, &$value, $min, $max, $botMax=null, $enforceLimits=false)
Validate the value against the minimum and user/bot maximum limits.
Definition: ApiBase.php:1569
const PARAM_DFLT
(null|boolean|integer|string) Default value of the parameter.
Definition: ApiBase.php:55
getMain()
Get the main module.
Definition: ApiBase.php:536
const LIMIT_BIG1
Fast query, standard limit.
Definition: ApiBase.php:259
const PARAM_MAX
(integer) Max value allowed for the parameter, for PARAM_TYPE &#39;integer&#39; and &#39;limit&#39;.
Definition: ApiBase.php:97
$sort
dieWithError( $msg, $code=null, $data=null, $httpCode=null)
Abort execution with an error.
Definition: ApiBase.php:2005
extractRequestParams( $options=[])
Using getAllowedParams(), this function makes an array of the values provided by the user...
Definition: ApiBase.php:761
setContinueEnumParameter( $paramName, $paramValue)
Overridden to set the generator param if in generator mode.
static setIndexedTagName(array &$arr, $tag)
Set the tag name for numeric-keyed values in XML format.
Definition: ApiResult.php:616
addTables( $tables, $alias=null)
Add a set of tables to the internal array.
dieContinueUsageIf( $condition)
Die with the &#39;badcontinue&#39; error.
Definition: ApiBase.php:2199
getModuleName()
Get the name of the module being executed by this instance.
Definition: ApiBase.php:520
addFields( $value)
Add a set of fields to select to the internal array.
const NS_FILE
Definition: Defines.php:66
const PARAM_MAX2
(integer) Max value allowed for the parameter for users with the apihighlimits right, for PARAM_TYPE &#39;limit&#39;.
Definition: ApiBase.php:103
This is the main query class.
Definition: ApiQuery.php:37
const PARAM_HELP_MSG
(string|array|Message) Specify an alternative i18n documentation message for this parameter...
Definition: ApiBase.php:131
const LIST_OR
Definition: Defines.php:42
static makeTitle( $ns, $title, $fragment='', $interwiki='')
Create a new Title from a namespace index and a DB key.
Definition: Title.php:586
addWhere( $value)
Add a set of WHERE clauses to the internal array.
const PARAM_ISMULTI
(boolean) Accept multiple pipe-separated values for this parameter (e.g.
Definition: ApiBase.php:58
addWhereFld( $field, $value)
Equivalent to addWhere( [ $field => $value ] )
addOption( $name, $value=null)
Add an option such as LIMIT or USE INDEX.
const PARAM_MIN
(integer) Lowest value allowed for the parameter, for PARAM_TYPE &#39;integer&#39; and &#39;limit&#39;.
Definition: ApiBase.php:106
resetQueryParams()
Blank the internal arrays with query parameters.