includes/api/ApiQueryBacklinks.php

   1 <?php
   2
   3
   4 /*
   5  * Created on Oct 16, 2006
   6  *
   7  * API for MediaWiki 1.8+
   8  *
   9  * Copyright (C) 2006 Yuri Astrakhan <FirstnameLastname@gmail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  * http://www.gnu.org/copyleft/gpl.html
  25  */
  26
  27 if (!defined('MEDIAWIKI')) {
  28         // Eclipse helper - will be ignored in production
  29         require_once ("ApiQueryBase.php");
  30 }
  31
  32 class ApiQueryBacklinks extends ApiQueryGeneratorBase {
  33
  34         private $rootTitle, $contRedirs, $contLevel, $contTitle, $contID;
  35
  36         // output element name, database column field prefix, database table
  37         private $backlinksSettings = array (
  38                 'backlinks' => array (
  39                         'code' => 'bl',
  40                         'prefix' => 'pl',
  41                         'linktbl' => 'pagelinks'
  42                 ),
  43                 'embeddedin' => array (
  44                         'code' => 'ei',
  45                         'prefix' => 'tl',
  46                         'linktbl' => 'templatelinks'
  47                 ),
  48                 'imagelinks' => array (
  49                         'code' => 'il',
  50                         'prefix' => 'il',
  51                         'linktbl' => 'imagelinks'
  52                 )
  53         );
  54
  55         public function __construct($query, $moduleName) {
  56                 $code = $prefix = $linktbl = null;
  57                 extract($this->backlinksSettings[$moduleName]);
  58
  59                 parent :: __construct($query, $moduleName, $code);
  60                 $this->bl_ns = $prefix . '_namespace';
  61                 $this->bl_from = $prefix . '_from';
  62                 $this->bl_tables = array (
  63                         $linktbl,
  64                         'page'
  65                 );
  66                 $this->bl_code = $code;
  67
  68                 $this->hasNS = $moduleName !== 'imagelinks';
  69                 if ($this->hasNS) {
  70                         $this->bl_title = $prefix . '_title';
  71                         $this->bl_sort = "{$this->bl_ns}, {$this->bl_title}, {$this->bl_from}";
  72                         $this->bl_fields = array (
  73                                 $this->bl_ns,
  74                                 $this->bl_title
  75                         );
  76                 } else {
  77                         $this->bl_title = $prefix . '_to';
  78                         $this->bl_sort = "{$this->bl_title}, {$this->bl_from}";
  79                         $this->bl_fields = array (
  80                                 $this->bl_title
  81                         );
  82                 }
  83         }
  84
  85         public function execute() {
  86                 $this->run();
  87         }
  88
  89         public function executeGenerator($resultPageSet) {
  90                 $this->run($resultPageSet);
  91         }
  92
  93         private function run($resultPageSet = null) {
  94                 $continue = $namespace = $redirect = $limit = null;
  95                 extract($this->extractRequestParams());
  96
  97                 if ($redirect)
  98                         ApiBase :: dieDebug(__METHOD__, 'Redirect is not yet been implemented', 'notimplemented');
  99
 100                 $this->processContinue($continue, $redirect);
 101
 102                 $this->addFields($this->bl_fields);
 103                 if (is_null($resultPageSet))
 104                         $this->addFields(array (
 105                                 'page_id',
 106                                 'page_namespace',
 107                                 'page_title'
 108                         ));
 109                 else
 110                         $this->addFields($resultPageSet->getPageTableFields()); // will include page_id
 111
 112                 $this->addTables($this->bl_tables);
 113                 $this->addWhere($this->bl_from . '=page_id');
 114
 115                 if ($this->hasNS)
 116                         $this->addWhereFld($this->bl_ns, $this->rootTitle->getNamespace());
 117                 $this->addWhereFld($this->bl_title, $this->rootTitle->getDBkey());
 118                 $this->addWhereFld('page_namespace', $namespace);
 119                 $this->addOption('LIMIT', $limit +1);
 120                 $this->addOption('ORDER BY', $this->bl_sort);
 121
 122                 if ($redirect)
 123                         $this->addWhereFld('page_is_redirect', 0);
 124
 125                 $db = $this->getDB();
 126                 if (!is_null($continue)) {
 127                         $plfrm = intval($this->contID);
 128                         if ($this->contLevel == 0) {
 129                                 // For the first level, there is only one target title, so no need for complex filtering
 130                                 $this->addWhere($this->bl_from . '>=' . $plfrm);
 131                         } else {
 132                                 $ns = $this->contTitle->getNamespace();
 133                                 $t = $db->addQuotes($this->contTitle->getDBkey());
 134                                 $whereWithoutNS = "{$this->bl_title}>$t OR ({$this->bl_title}=$t AND {$this->bl_from}>=$plfrm))";
 135
 136                                 if ($this->hasNS)
 137                                         $this->addWhere("{$this->bl_ns}>$ns OR ({$this->bl_ns}=$ns AND ($whereWithoutNS)");
 138                                 else
 139                                         $this->addWhere($whereWithoutNS);
 140                         }
 141                 }
 142
 143                 $res = $this->select(__METHOD__);
 144
 145                 $count = 0;
 146                 $data = array ();
 147                 while ($row = $db->fetchObject($res)) {
 148                         if (++ $count > $limit) {
 149                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 150                                 if ($redirect) {
 151                                         $ns = $row-> {
 152                                                 $this->bl_ns };
 153                                         $t = $row-> {
 154                                                 $this->bl_title };
 155                                         $continue = $this->getContinueRedirStr(false, 0, $ns, $t, $row->page_id);
 156                                 } else
 157                                         $continue = $this->getContinueStr($row->page_id);
 158                                 $this->setContinueEnumParameter('continue', $continue);
 159                                 break;
 160                         }
 161
 162                         if (is_null($resultPageSet)) {
 163                                 $vals = $this->addRowInfo('page', $row);
 164                                 if ($vals)
 165                                         $data[intval($row->page_id)] = $vals;
 166                         } else {
 167                                 $resultPageSet->processDbRow($row);
 168                         }
 169                 }
 170                 $db->freeResult($res);
 171
 172                 if (is_null($resultPageSet)) {
 173                         $result = $this->getResult();
 174                         $result->setIndexedTagName($data, $this->bl_code);
 175                         $result->addValue('query', $this->getModuleName(), $data);
 176                 }
 177         }
 178
 179         protected function processContinue($continue, $redirect) {
 180                 $pageSet = $this->getPageSet();
 181                 $count = $pageSet->getTitleCount();
 182                 if (!is_null($continue)) {
 183                         if ($count !== 0)
 184                                 $this->dieUsage("When continuing the {$this->getModuleName()} query, no other titles may be provided", 'titles_on_continue');
 185                         $this->parseContinueParam($continue, $redirect);
 186
 187                         // Skip all completed links
 188
 189                 } else {
 190                         if ($count !== 1)
 191                                 $this->dieUsage("The {$this->getModuleName()} query requires one title to start", 'bad_title_count');
 192                         $this->rootTitle = current($pageSet->getTitles()); // only one title there
 193                 }
 194
 195                 // only image titles are allowed for the root
 196                 if (!$this->hasNS && $this->rootTitle->getNamespace() !== NS_IMAGE)
 197                         $this->dieUsage("The title for {$this->getModuleName()} query must be an image", 'bad_image_title');
 198         }
 199
 200         protected function parseContinueParam($continue, $redirect) {
 201                 $continueList = explode('|', $continue);
 202                 if ($redirect) {
 203                         //
 204                         // expected redirect-mode parameter:
 205                         // ns|db_key|step|level|ns|db_key|id
 206                         // ns+db_key -- the root title
 207                         // step = 1 or 2 - which step to continue from - 1-titles, 2-redirects
 208                         // level -- how many levels to follow before starting enumerating.
 209                         // if level > 0 -- ns+title to continue from, otherwise skip these
 210                         // id = last page_id to continue from
 211                         //
 212                         if (count($continueList) > 4) {
 213                                 $rootNs = intval($continueList[0]);
 214                                 if (($rootNs !== 0 || $continueList[0] === '0') && !empty ($continueList[1])) {
 215                                         $this->rootTitle = Title :: makeTitleSafe($rootNs, $continueList[1]);
 216                                         if ($this->rootTitle && $this->rootTitle->userCanRead()) {
 217
 218                                                 $step = intval($continueList[2]);
 219                                                 if ($step === 1 || $step === 2) {
 220                                                         $this->contRedirs = ($step === 2);
 221
 222                                                         $level = intval($continueList[3]);
 223                                                         if ($level !== 0 || $continueList[3] === '0') {
 224                                                                 $this->contLevel = $level;
 225
 226                                                                 if ($level === 0) {
 227                                                                         if (count($continueList) === 5) {
 228                                                                                 $contID = intval($continueList[4]);
 229                                                                                 if ($contID !== 0 || $continueList[4] === '0') {
 230                                                                                         $this->contID = $contID;
 231                                                                                         return; // done
 232                                                                                 }
 233                                                                         }
 234                                                                 } else {
 235                                                                         if (count($continueList) === 7) {
 236                                                                                 $contNs = intval($continueList[4]);
 237                                                                                 if (($contNs !== 0 || $continueList[4] === '0') && !empty ($continueList[5])) {
 238                                                                                         $this->contTitle = Title :: makeTitleSafe($contNs, $continueList[5]);
 239
 240                                                                                         $contID = intval($continueList[6]);
 241                                                                                         if ($contID !== 0 || $continueList[6] === '0') {
 242                                                                                                 $this->contID = $contID;
 243                                                                                                 return; // done
 244                                                                                         }
 245                                                                                 }
 246                                                                         }
 247                                                                 }
 248                                                         }
 249                                                 }
 250                                         }
 251                                 }
 252                         }
 253                 } else {
 254                         //
 255                         // expected non-redirect-mode parameter:
 256                         // ns|db_key|id
 257                         // ns+db_key -- the root title
 258                         // id = last page_id to continue from
 259                         //
 260                         if (count($continueList) === 3) {
 261                                 $rootNs = intval($continueList[0]);
 262                                 if (($rootNs !== 0 || $continueList[0] === '0') && !empty ($continueList[1])) {
 263                                         $this->rootTitle = Title :: makeTitleSafe($rootNs, $continueList[1]);
 264                                         if ($this->rootTitle && $this->rootTitle->userCanRead()) {
 265
 266                                                 $contID = intval($continueList[2]);
 267                                                 if ($contID !== 0) {
 268                                                         $this->contID = $contID;
 269                                                         return; // done
 270                                                 }
 271                                         }
 272                                 }
 273                         }
 274                 }
 275
 276                 $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
 277         }
 278
 279         protected function getContinueStr($lastPageID) {
 280                 return $this->rootTitle->getNamespace() .
 281                 '|' . $this->rootTitle->getDBkey() .
 282                 '|' . $lastPageID;
 283         }
 284
 285         protected function getContinueRedirStr($isRedirPhase, $level, $ns, $title, $lastPageID) {
 286                 return $this->rootTitle->getNamespace() .
 287                 '|' . $this->rootTitle->getDBkey() .
 288                 '|' . ($isRedirPhase ? 1 : 2) .
 289                 '|' . $level .
 290                  ($level > 0 ? ('|' . $ns . '|' . $title) : '') .
 291                 '|' . $lastPageID;
 292         }
 293
 294         protected function getAllowedParams() {
 295
 296                 return array (
 297                         'continue' => null,
 298                         'namespace' => array (
 299                                 ApiBase :: PARAM_ISMULTI => true,
 300                                 ApiBase :: PARAM_TYPE => 'namespace'
 301                         ),
 302                         'redirect' => false,
 303                         'limit' => array (
 304                                 ApiBase :: PARAM_DFLT => 10,
 305                                 ApiBase :: PARAM_TYPE => 'limit',
 306                                 ApiBase :: PARAM_MIN => 1,
 307                                 ApiBase :: PARAM_MAX1 => ApiBase :: LIMIT_BIG1,
 308                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 309                         )
 310                 );
 311         }
 312
 313         protected function getParamDescription() {
 314                 return array (
 315                         'continue' => 'When more results are available, use this to continue.',
 316                         'namespace' => 'The namespace to enumerate.',
 317                         'redirect' => 'If linking page is a redirect, find all pages that link to that redirect (not implemented)',
 318                         'limit' => 'How many total pages to return.'
 319                 );
 320         }
 321
 322         protected function getDescription() {
 323                 switch ($this->getModuleName()) {
 324                         case 'backlinks' :
 325                                 return 'Find all pages that link to the given page';
 326                         case 'embeddedin' :
 327                                 return 'Find all pages that embed (transclude) the given title';
 328                         case 'imagelinks' :
 329                                 return 'Find all pages that use the given image title.';
 330                         default :
 331                                 ApiBase :: dieDebug(__METHOD__, 'Unknown module name');
 332                 }
 333         }
 334
 335         protected function getExamples() {
 336                 static $examples = array (
 337                         'backlinks' => array (
 338                                 "api.php?action=query&list=backlinks&titles=Main%20Page",
 339                                 "api.php?action=query&generator=backlinks&titles=Main%20Page&prop=info"
 340                         ),
 341                         'embeddedin' => array (
 342                                 "api.php?action=query&list=embeddedin&titles=Template:Stub",
 343                                 "api.php?action=query&generator=embeddedin&titles=Template:Stub&prop=info"
 344                         ),
 345                         'imagelinks' => array (
 346                                 "api.php?action=query&list=imagelinks&titles=Image:Albert%20Einstein%20Head.jpg",
 347                                 "api.php?action=query&generator=imagelinks&titles=Image:Albert%20Einstein%20Head.jpg&prop=info"
 348                         )
 349                 );
 350
 351                 return $examples[$this->getModuleName()];
 352         }
 353
 354         public function getVersion() {
 355                 return __CLASS__ . ': $Id$';
 356         }
 357 }
 358 ?>