resources/src/mediawiki/mediawiki.Title.js

   1 /*!
   2  * @author Neil Kandalgaonkar, 2010
   3  * @author Timo Tijhof, 2011-2013
   4  * @since 1.18
   5  */
   6 ( function ( mw, $ ) {
   7         /*jshint latedef:false */
   8
   9         /**
  10          * @class mw.Title
  11          *
  12          * Parse titles into an object structure. Note that when using the constructor
  13          * directly, passing invalid titles will result in an exception. Use #newFromText to use the
  14          * logic directly and get null for invalid titles which is easier to work with.
  15          *
  16          * @constructor
  17          * @param {string} title Title of the page. If no second argument given,
  18          *  this will be searched for a namespace
  19          * @param {number} [namespace=NS_MAIN] If given, will used as default namespace for the given title
  20          * @throws {Error} When the title is invalid
  21          */
  22         function Title( title, namespace ) {
  23                 var parsed = parse( title, namespace );
  24                 if ( !parsed ) {
  25                         throw new Error( 'Unable to parse title' );
  26                 }
  27
  28                 this.namespace = parsed.namespace;
  29                 this.title = parsed.title;
  30                 this.ext = parsed.ext;
  31                 this.fragment = parsed.fragment;
  32
  33                 return this;
  34         }
  35
  36         /* Private members */
  37
  38         var
  39
  40         /**
  41          * @private
  42          * @static
  43          * @property NS_MAIN
  44          */
  45         NS_MAIN = 0,
  46
  47         /**
  48          * @private
  49          * @static
  50          * @property NS_TALK
  51          */
  52         NS_TALK = 1,
  53
  54         /**
  55          * @private
  56          * @static
  57          * @property NS_SPECIAL
  58          */
  59         NS_SPECIAL = -1,
  60
  61         /**
  62          * @private
  63          * @static
  64          * @property NS_MEDIA
  65          */
  66         NS_MEDIA = -2,
  67
  68         /**
  69          * @private
  70          * @static
  71          * @property NS_FILE
  72          */
  73         NS_FILE = 6,
  74
  75         /**
  76          * @private
  77          * @static
  78          * @property FILENAME_MAX_BYTES
  79          */
  80         FILENAME_MAX_BYTES = 240,
  81
  82         /**
  83          * @private
  84          * @static
  85          * @property TITLE_MAX_BYTES
  86          */
  87         TITLE_MAX_BYTES = 255,
  88
  89         /**
  90          * Get the namespace id from a namespace name (either from the localized, canonical or alias
  91          * name).
  92          *
  93          * Example: On a German wiki this would return 6 for any of 'File', 'Datei', 'Image' or
  94          * even 'Bild'.
  95          *
  96          * @private
  97          * @static
  98          * @method getNsIdByName
  99          * @param {string} ns Namespace name (case insensitive, leading/trailing space ignored)
 100          * @return {number|boolean} Namespace id or boolean false
 101          */
 102         getNsIdByName = function ( ns ) {
 103                 var id;
 104
 105                 // Don't cast non-strings to strings, because null or undefined should not result in
 106                 // returning the id of a potential namespace called "Null:" (e.g. on null.example.org/wiki)
 107                 // Also, toLowerCase throws exception on null/undefined, because it is a String method.
 108                 if ( typeof ns !== 'string' ) {
 109                         return false;
 110                 }
 111                 ns = ns.toLowerCase();
 112                 id = mw.config.get( 'wgNamespaceIds' )[ ns ];
 113                 if ( id === undefined ) {
 114                         return false;
 115                 }
 116                 return id;
 117         },
 118
 119         rUnderscoreTrim = /^_+|_+$/g,
 120
 121         rSplit = /^(.+?)_*:_*(.*)$/,
 122
 123         // See MediaWikiTitleCodec.php#getTitleInvalidRegex
 124         rInvalid = new RegExp(
 125                 '[^' + mw.config.get( 'wgLegalTitleChars' ) + ']' +
 126                 // URL percent encoding sequences interfere with the ability
 127                 // to round-trip titles -- you can't link to them consistently.
 128                 '|%[0-9A-Fa-f]{2}' +
 129                 // XML/HTML character references produce similar issues.
 130                 '|&[A-Za-z0-9\u0080-\uFFFF]+;' +
 131                 '|&#[0-9]+;' +
 132                 '|&#x[0-9A-Fa-f]+;'
 133         ),
 134
 135         // From MediaWikiTitleCodec.php#L225 @26fcab1f18c568a41
 136         // "Clean up whitespace" in function MediaWikiTitleCodec::splitTitleString()
 137         rWhitespace = /[ _\u0009\u00A0\u1680\u180E\u2000-\u200A\u2028\u2029\u202F\u205F\u3000\s]+/g,
 138
 139         /**
 140          * Slightly modified from Flinfo. Credit goes to Lupo and Flominator.
 141          * @private
 142          * @static
 143          * @property sanitationRules
 144          */
 145         sanitationRules = [
 146                 // "signature"
 147                 {
 148                         pattern: /~{3}/g,
 149                         replace: '',
 150                         generalRule: true
 151                 },
 152                 // Space, underscore, tab, NBSP and other unusual spaces
 153                 {
 154                         pattern: rWhitespace,
 155                         replace: ' ',
 156                         generalRule: true
 157                 },
 158                 // unicode bidi override characters: Implicit, Embeds, Overrides
 159                 {
 160                         pattern: /[\u200E\u200F\u202A-\u202E]/g,
 161                         replace: '',
 162                         generalRule: true
 163                 },
 164                 // control characters
 165                 {
 166                         pattern: /[\x00-\x1f\x7f]/g,
 167                         replace: '',
 168                         generalRule: true
 169                 },
 170                 // URL encoding (possibly)
 171                 {
 172                         pattern: /%([0-9A-Fa-f]{2})/g,
 173                         replace: '% $1',
 174                         generalRule: true
 175                 },
 176                 // HTML-character-entities
 177                 {
 178                         pattern: /&(([A-Za-z0-9\x80-\xff]+|#[0-9]+|#x[0-9A-Fa-f]+);)/g,
 179                         replace: '& $1',
 180                         generalRule: true
 181                 },
 182                 // slash, colon (not supported by file systems like NTFS/Windows, Mac OS 9 [:], ext4 [/])
 183                 {
 184                         pattern: /[:\/#]/g,
 185                         replace: '-',
 186                         fileRule: true
 187                 },
 188                 // brackets, greater than
 189                 {
 190                         pattern: /[\]\}>]/g,
 191                         replace: ')',
 192                         generalRule: true
 193                 },
 194                 // brackets, lower than
 195                 {
 196                         pattern: /[\[\{<]/g,
 197                         replace: '(',
 198                         generalRule: true
 199                 },
 200                 // everything that wasn't covered yet
 201                 {
 202                         pattern: new RegExp( rInvalid.source, 'g' ),
 203                         replace: '-',
 204                         generalRule: true
 205                 },
 206                 // directory structures
 207                 {
 208                         pattern: /^(\.|\.\.|\.\/.*|\.\.\/.*|.*\/\.\/.*|.*\/\.\.\/.*|.*\/\.|.*\/\.\.)$/g,
 209                         replace: '',
 210                         generalRule: true
 211                 }
 212         ],
 213
 214         /**
 215          * Internal helper for #constructor and #newFromtext.
 216          *
 217          * Based on Title.php#secureAndSplit
 218          *
 219          * @private
 220          * @static
 221          * @method parse
 222          * @param {string} title
 223          * @param {number} [defaultNamespace=NS_MAIN]
 224          * @return {Object|boolean}
 225          */
 226         parse = function ( title, defaultNamespace ) {
 227                 var namespace, m, id, i, fragment, ext;
 228
 229                 namespace = defaultNamespace === undefined ? NS_MAIN : defaultNamespace;
 230
 231                 title = title
 232                         // Normalise whitespace to underscores and remove duplicates
 233                         .replace( /[ _\s]+/g, '_' )
 234                         // Trim underscores
 235                         .replace( rUnderscoreTrim, '' );
 236
 237                 // Process initial colon
 238                 if ( title !== '' && title[ 0 ] === ':' ) {
 239                         // Initial colon means main namespace instead of specified default
 240                         namespace = NS_MAIN;
 241                         title = title
 242                                 // Strip colon
 243                                 .slice( 1 )
 244                                 // Trim underscores
 245                                 .replace( rUnderscoreTrim, '' );
 246                 }
 247
 248                 if ( title === '' ) {
 249                         return false;
 250                 }
 251
 252                 // Process namespace prefix (if any)
 253                 m = title.match( rSplit );
 254                 if ( m ) {
 255                         id = getNsIdByName( m[ 1 ] );
 256                         if ( id !== false ) {
 257                                 // Ordinary namespace
 258                                 namespace = id;
 259                                 title = m[ 2 ];
 260
 261                                 // For Talk:X pages, make sure X has no "namespace" prefix
 262                                 if ( namespace === NS_TALK && ( m = title.match( rSplit ) ) ) {
 263                                         // Disallow titles like Talk:File:x (subject should roundtrip: talk:file:x -> file:x -> file_talk:x)
 264                                         if ( getNsIdByName( m[ 1 ] ) !== false ) {
 265                                                 return false;
 266                                         }
 267                                 }
 268                         }
 269                 }
 270
 271                 // Process fragment
 272                 i = title.indexOf( '#' );
 273                 if ( i === -1 ) {
 274                         fragment = null;
 275                 } else {
 276                         fragment = title
 277                                 // Get segment starting after the hash
 278                                 .slice( i + 1 )
 279                                 // Convert to text
 280                                 // NB: Must not be trimmed ("Example#_foo" is not the same as "Example#foo")
 281                                 .replace( /_/g, ' ' );
 282
 283                         title = title
 284                                 // Strip hash
 285                                 .slice( 0, i )
 286                                 // Trim underscores, again (strips "_" from "bar" in "Foo_bar_#quux")
 287                                 .replace( rUnderscoreTrim, '' );
 288                 }
 289
 290                 // Reject illegal characters
 291                 if ( title.match( rInvalid ) ) {
 292                         return false;
 293                 }
 294
 295                 // Disallow titles that browsers or servers might resolve as directory navigation
 296                 if (
 297                         title.indexOf( '.' ) !== -1 && (
 298                                 title === '.' || title === '..' ||
 299                                 title.indexOf( './' ) === 0 ||
 300                                 title.indexOf( '../' ) === 0 ||
 301                                 title.indexOf( '/./' ) !== -1 ||
 302                                 title.indexOf( '/../' ) !== -1 ||
 303                                 title.slice( -2 ) === '/.' ||
 304                                 title.slice( -3 ) === '/..'
 305                         )
 306                 ) {
 307                         return false;
 308                 }
 309
 310                 // Disallow magic tilde sequence
 311                 if ( title.indexOf( '~~~' ) !== -1 ) {
 312                         return false;
 313                 }
 314
 315                 // Disallow titles exceeding the TITLE_MAX_BYTES byte size limit (size of underlying database field)
 316                 // Except for special pages, e.g. [[Special:Block/Long name]]
 317                 // Note: The PHP implementation also asserts that even in NS_SPECIAL, the title should
 318                 // be less than 512 bytes.
 319                 if ( namespace !== NS_SPECIAL && $.byteLength( title ) > TITLE_MAX_BYTES ) {
 320                         return false;
 321                 }
 322
 323                 // Can't make a link to a namespace alone.
 324                 if ( title === '' && namespace !== NS_MAIN ) {
 325                         return false;
 326                 }
 327
 328                 // Any remaining initial :s are illegal.
 329                 if ( title[ 0 ] === ':' ) {
 330                         return false;
 331                 }
 332
 333                 // For backwards-compatibility with old mw.Title, we separate the extension from the
 334                 // rest of the title.
 335                 i = title.lastIndexOf( '.' );
 336                 if ( i === -1 || title.length <= i + 1 ) {
 337                         // Extensions are the non-empty segment after the last dot
 338                         ext = null;
 339                 } else {
 340                         ext = title.slice( i + 1 );
 341                         title = title.slice( 0, i );
 342                 }
 343
 344                 return {
 345                         namespace: namespace,
 346                         title: title,
 347                         ext: ext,
 348                         fragment: fragment
 349                 };
 350         },
 351
 352         /**
 353          * Convert db-key to readable text.
 354          *
 355          * @private
 356          * @static
 357          * @method text
 358          * @param {string} s
 359          * @return {string}
 360          */
 361         text = function ( s ) {
 362                 if ( s !== null && s !== undefined ) {
 363                         return s.replace( /_/g, ' ' );
 364                 } else {
 365                         return '';
 366                 }
 367         },
 368
 369         /**
 370          * Sanitizes a string based on a rule set and a filter
 371          *
 372          * @private
 373          * @static
 374          * @method sanitize
 375          * @param {string} s
 376          * @param {Array} filter
 377          * @return {string}
 378          */
 379         sanitize = function ( s, filter ) {
 380                 var i, ruleLength, rule, m, filterLength,
 381                         rules = sanitationRules;
 382
 383                 for ( i = 0, ruleLength = rules.length; i < ruleLength; ++i ) {
 384                         rule = rules[ i ];
 385                         for ( m = 0, filterLength = filter.length; m < filterLength; ++m ) {
 386                                 if ( rule[ filter[ m ] ] ) {
 387                                         s = s.replace( rule.pattern, rule.replace );
 388                                 }
 389                         }
 390                 }
 391                 return s;
 392         },
 393
 394         /**
 395          * Cuts a string to a specific byte length, assuming UTF-8
 396          * or less, if the last character is a multi-byte one
 397          *
 398          * @private
 399          * @static
 400          * @method trimToByteLength
 401          * @param {string} s
 402          * @param {number} length
 403          * @return {string}
 404          */
 405         trimToByteLength = function ( s, length ) {
 406                 var byteLength, chopOffChars, chopOffBytes;
 407
 408                 // bytelength is always greater or equal to the length in characters
 409                 s = s.substr( 0, length );
 410                 while ( ( byteLength = $.byteLength( s ) ) > length ) {
 411                         // Calculate how many characters can be safely removed
 412                         // First, we need to know how many bytes the string exceeds the threshold
 413                         chopOffBytes = byteLength - length;
 414                         // A character in UTF-8 is at most 4 bytes
 415                         // One character must be removed in any case because the
 416                         // string is too long
 417                         chopOffChars = Math.max( 1, Math.floor( chopOffBytes / 4 ) );
 418                         s = s.substr( 0, s.length - chopOffChars );
 419                 }
 420                 return s;
 421         },
 422
 423         /**
 424          * Cuts a file name to a specific byte length
 425          *
 426          * @private
 427          * @static
 428          * @method trimFileNameToByteLength
 429          * @param {string} name without extension
 430          * @param {string} extension file extension
 431          * @return {string} The full name, including extension
 432          */
 433         trimFileNameToByteLength = function ( name, extension ) {
 434                 // There is a special byte limit for file names and ... remember the dot
 435                 return trimToByteLength( name, FILENAME_MAX_BYTES - extension.length - 1 ) + '.' + extension;
 436         },
 437
 438         // Polyfill for ES5 Object.create
 439         createObject = Object.create || ( function () {
 440                 return function ( o ) {
 441                         function Title() {}
 442                         if ( o !== Object( o ) ) {
 443                                 throw new Error( 'Cannot inherit from a non-object' );
 444                         }
 445                         Title.prototype = o;
 446                         return new Title();
 447                 };
 448         }() );
 449
 450         /* Static members */
 451
 452         /**
 453          * Constructor for Title objects with a null return instead of an exception for invalid titles.
 454          *
 455          * @static
 456          * @param {string} title
 457          * @param {number} [namespace=NS_MAIN] Default namespace
 458          * @return {mw.Title|null} A valid Title object or null if the title is invalid
 459          */
 460         Title.newFromText = function ( title, namespace ) {
 461                 var t, parsed = parse( title, namespace );
 462                 if ( !parsed ) {
 463                         return null;
 464                 }
 465
 466                 t = createObject( Title.prototype );
 467                 t.namespace = parsed.namespace;
 468                 t.title = parsed.title;
 469                 t.ext = parsed.ext;
 470                 t.fragment = parsed.fragment;
 471
 472                 return t;
 473         };
 474
 475         /**
 476          * Constructor for Title objects from user input altering that input to
 477          * produce a title that MediaWiki will accept as legal
 478          *
 479          * @static
 480          * @param {string} title
 481          * @param {number} [defaultNamespace=NS_MAIN]
 482          *  If given, will used as default namespace for the given title.
 483          * @param {Object} [options] additional options
 484          * @param {string} [options.fileExtension='']
 485          *  If the title is about to be created for the Media or File namespace,
 486          *  ensures the resulting Title has the correct extension. Useful, for example
 487          *  on systems that predict the type by content-sniffing, not by file extension.
 488          *  If different from empty string, `forUploading` is assumed.
 489          * @param {boolean} [options.forUploading=true]
 490          *  Makes sure that a file is uploadable under the title returned.
 491          *  There are pages in the file namespace under which file upload is impossible.
 492          *  Automatically assumed if the title is created in the Media namespace.
 493          * @return {mw.Title|null} A valid Title object or null if the input cannot be turned into a valid title
 494          */
 495         Title.newFromUserInput = function ( title, defaultNamespace, options ) {
 496                 var namespace, m, id, ext, parts, normalizeExtension;
 497
 498                 // defaultNamespace is optional; check whether options moves up
 499                 if ( arguments.length < 3 && $.type( defaultNamespace ) === 'object' ) {
 500                         options = defaultNamespace;
 501                         defaultNamespace = undefined;
 502                 }
 503
 504                 // merge options into defaults
 505                 options = $.extend( {
 506                         fileExtension: '',
 507                         forUploading: true
 508                 }, options );
 509
 510                 normalizeExtension = function ( extension ) {
 511                         // Remove only trailing space (that is removed by MW anyway)
 512                         extension = extension.toLowerCase().replace( /\s*$/, '' );
 513                         return extension;
 514                 };
 515
 516                 namespace = defaultNamespace === undefined ? NS_MAIN : defaultNamespace;
 517
 518                 // Normalise whitespace and remove duplicates
 519                 title = $.trim( title.replace( rWhitespace, ' ' ) );
 520
 521                 // Process initial colon
 522                 if ( title !== '' && title[ 0 ] === ':' ) {
 523                         // Initial colon means main namespace instead of specified default
 524                         namespace = NS_MAIN;
 525                         title = title
 526                                 // Strip colon
 527                                 .substr( 1 )
 528                                 // Trim underscores
 529                                 .replace( rUnderscoreTrim, '' );
 530                 }
 531
 532                 // Process namespace prefix (if any)
 533                 m = title.match( rSplit );
 534                 if ( m ) {
 535                         id = getNsIdByName( m[ 1 ] );
 536                         if ( id !== false ) {
 537                                 // Ordinary namespace
 538                                 namespace = id;
 539                                 title = m[ 2 ];
 540                         }
 541                 }
 542
 543                 if ( namespace === NS_MEDIA
 544                         || ( ( options.forUploading || options.fileExtension ) && ( namespace === NS_FILE ) )
 545                 ) {
 546
 547                         title = sanitize( title, [ 'generalRule', 'fileRule' ] );
 548
 549                         // Operate on the file extension
 550                         // Although it is possible having spaces between the name and the ".ext" this isn't nice for
 551                         // operating systems hiding file extensions -> strip them later on
 552                         parts = title.split( '.' );
 553
 554                         if ( parts.length > 1 ) {
 555
 556                                 // Get the last part, which is supposed to be the file extension
 557                                 ext = parts.pop();
 558
 559                                 // Does the supplied file name carry the desired file extension?
 560                                 if ( options.fileExtension
 561                                         && normalizeExtension( ext ) !== normalizeExtension( options.fileExtension )
 562                                 ) {
 563
 564                                         // No, push back, whatever there was after the dot
 565                                         parts.push( ext );
 566
 567                                         // And add the desired file extension later
 568                                         ext = options.fileExtension;
 569                                 }
 570
 571                                 // Remove whitespace of the name part (that W/O extension)
 572                                 title = $.trim( parts.join( '.' ) );
 573
 574                                 // Cut, if too long and append file extension
 575                                 title = trimFileNameToByteLength( title, ext );
 576
 577                         } else {
 578
 579                                 // Missing file extension
 580                                 title = $.trim( parts.join( '.' ) );
 581
 582                                 if ( options.fileExtension ) {
 583
 584                                         // Cut, if too long and append the desired file extension
 585                                         title = trimFileNameToByteLength( title, options.fileExtension );
 586
 587                                 } else {
 588
 589                                         // Name has no file extension and a fallback wasn't provided either
 590                                         return null;
 591                                 }
 592                         }
 593                 } else {
 594
 595                         title = sanitize( title, [ 'generalRule' ] );
 596
 597                         // Cut titles exceeding the TITLE_MAX_BYTES byte size limit
 598                         // (size of underlying database field)
 599                         if ( namespace !== NS_SPECIAL ) {
 600                                 title = trimToByteLength( title, TITLE_MAX_BYTES );
 601                         }
 602                 }
 603
 604                 // Any remaining initial :s are illegal.
 605                 title = title.replace( /^\:+/, '' );
 606
 607                 return Title.newFromText( title, namespace );
 608         };
 609
 610         /**
 611          * Sanitizes a file name as supplied by the user, originating in the user's file system
 612          * so it is most likely a valid MediaWiki title and file name after processing.
 613          * Returns null on fatal errors.
 614          *
 615          * @static
 616          * @param {string} uncleanName The unclean file name including file extension but
 617          *   without namespace
 618          * @param {string} [fileExtension] the desired file extension
 619          * @return {mw.Title|null} A valid Title object or null if the title is invalid
 620          */
 621         Title.newFromFileName = function ( uncleanName, fileExtension ) {
 622
 623                 return Title.newFromUserInput( 'File:' + uncleanName, {
 624                         fileExtension: fileExtension,
 625                         forUploading: true
 626                 } );
 627         };
 628
 629         /**
 630          * Get the file title from an image element
 631          *
 632          *     var title = mw.Title.newFromImg( $( 'img:first' ) );
 633          *
 634          * @static
 635          * @param {HTMLElement|jQuery} img The image to use as a base
 636          * @return {mw.Title|null} The file title or null if unsuccessful
 637          */
 638         Title.newFromImg = function ( img ) {
 639                 var matches, i, regex, src, decodedSrc,
 640
 641                         // thumb.php-generated thumbnails
 642                         thumbPhpRegex = /thumb\.php/,
 643                         regexes = [
 644                                 // Thumbnails
 645                                 /\/[a-f0-9]\/[a-f0-9]{2}\/([^\s\/]+)\/[^\s\/]+-(?:\1|thumbnail)[^\s\/]*$/,
 646
 647                                 // Thumbnails in non-hashed upload directories
 648                                 /\/([^\s\/]+)\/[^\s\/]+-(?:\1|thumbnail)[^\s\/]*$/,
 649
 650                                 // Full size images
 651                                 /\/[a-f0-9]\/[a-f0-9]{2}\/([^\s\/]+)$/,
 652
 653                                 // Full-size images in non-hashed upload directories
 654                                 /\/([^\s\/]+)$/
 655                         ],
 656
 657                         recount = regexes.length;
 658
 659                 src = img.jquery ? img[ 0 ].src : img.src;
 660
 661                 matches = src.match( thumbPhpRegex );
 662
 663                 if ( matches ) {
 664                         return mw.Title.newFromText( 'File:' + mw.util.getParamValue( 'f', src ) );
 665                 }
 666
 667                 decodedSrc = decodeURIComponent( src );
 668
 669                 for ( i = 0; i < recount; i++ ) {
 670                         regex = regexes[ i ];
 671                         matches = decodedSrc.match( regex );
 672
 673                         if ( matches && matches[ 1 ] ) {
 674                                 return mw.Title.newFromText( 'File:' + matches[ 1 ] );
 675                         }
 676                 }
 677
 678                 return null;
 679         };
 680
 681         /**
 682          * Whether this title exists on the wiki.
 683          *
 684          * @static
 685          * @param {string|mw.Title} title prefixed db-key name (string) or instance of Title
 686          * @return {boolean|null} Boolean if the information is available, otherwise null
 687          */
 688         Title.exists = function ( title ) {
 689                 var match,
 690                         type = $.type( title ),
 691                         obj = Title.exist.pages;
 692
 693                 if ( type === 'string' ) {
 694                         match = obj[ title ];
 695                 } else if ( type === 'object' && title instanceof Title ) {
 696                         match = obj[ title.toString() ];
 697                 } else {
 698                         throw new Error( 'mw.Title.exists: title must be a string or an instance of Title' );
 699                 }
 700
 701                 if ( typeof match === 'boolean' ) {
 702                         return match;
 703                 }
 704
 705                 return null;
 706         };
 707
 708         /**
 709          * Store page existence
 710          *
 711          * @static
 712          * @property {Object} exist
 713          * @property {Object} exist.pages Keyed by title. Boolean true value indicates page does exist.
 714          *
 715          * @property {Function} exist.set The setter function.
 716          *
 717          *  Example to declare existing titles:
 718          *
 719          *     Title.exist.set( ['User:John_Doe', ...] );
 720          *
 721          *  Example to declare titles nonexistent:
 722          *
 723          *     Title.exist.set( ['File:Foo_bar.jpg', ...], false );
 724          *
 725          * @property {string|Array} exist.set.titles Title(s) in strict prefixedDb title form
 726          * @property {boolean} [exist.set.state=true] State of the given titles
 727          * @return {boolean}
 728          */
 729         Title.exist = {
 730                 pages: {},
 731
 732                 set: function ( titles, state ) {
 733                         titles = $.isArray( titles ) ? titles : [ titles ];
 734                         state = state === undefined ? true : !!state;
 735                         var i,
 736                                 pages = this.pages,
 737                                 len = titles.length;
 738
 739                         for ( i = 0; i < len; i++ ) {
 740                                 pages[ titles[ i ] ] = state;
 741                         }
 742                         return true;
 743                 }
 744         };
 745
 746         /* Public members */
 747
 748         Title.prototype = {
 749                 constructor: Title,
 750
 751                 /**
 752                  * Get the namespace number
 753                  *
 754                  * Example: 6 for "File:Example_image.svg".
 755                  *
 756                  * @return {number}
 757                  */
 758                 getNamespaceId: function () {
 759                         return this.namespace;
 760                 },
 761
 762                 /**
 763                  * Get the namespace prefix (in the content language)
 764                  *
 765                  * Example: "File:" for "File:Example_image.svg".
 766                  * In #NS_MAIN this is '', otherwise namespace name plus ':'
 767                  *
 768                  * @return {string}
 769                  */
 770                 getNamespacePrefix: function () {
 771                         return this.namespace === NS_MAIN ?
 772                                 '' :
 773                                 ( mw.config.get( 'wgFormattedNamespaces' )[ this.namespace ].replace( / /g, '_' ) + ':' );
 774                 },
 775
 776                 /**
 777                  * Get the page name without extension or namespace prefix
 778                  *
 779                  * Example: "Example_image" for "File:Example_image.svg".
 780                  *
 781                  * For the page title (full page name without namespace prefix), see #getMain.
 782                  *
 783                  * @return {string}
 784                  */
 785                 getName: function () {
 786                         if (
 787                                 $.inArray( this.namespace, mw.config.get( 'wgCaseSensitiveNamespaces' ) ) !== -1 ||
 788                                 !this.title.length
 789                         ) {
 790                                 return this.title;
 791                         }
 792                         return this.title[ 0 ].toUpperCase() + this.title.slice( 1 );
 793                 },
 794
 795                 /**
 796                  * Get the page name (transformed by #text)
 797                  *
 798                  * Example: "Example image" for "File:Example_image.svg".
 799                  *
 800                  * For the page title (full page name without namespace prefix), see #getMainText.
 801                  *
 802                  * @return {string}
 803                  */
 804                 getNameText: function () {
 805                         return text( this.getName() );
 806                 },
 807
 808                 /**
 809                  * Get the extension of the page name (if any)
 810                  *
 811                  * @return {string|null} Name extension or null if there is none
 812                  */
 813                 getExtension: function () {
 814                         return this.ext;
 815                 },
 816
 817                 /**
 818                  * Shortcut for appendable string to form the main page name.
 819                  *
 820                  * Returns a string like ".json", or "" if no extension.
 821                  *
 822                  * @return {string}
 823                  */
 824                 getDotExtension: function () {
 825                         return this.ext === null ? '' : '.' + this.ext;
 826                 },
 827
 828                 /**
 829                  * Get the main page name
 830                  *
 831                  * Example: "Example_image.svg" for "File:Example_image.svg".
 832                  *
 833                  * @return {string}
 834                  */
 835                 getMain: function () {
 836                         return this.getName() + this.getDotExtension();
 837                 },
 838
 839                 /**
 840                  * Get the main page name (transformed by #text)
 841                  *
 842                  * Example: "Example image.svg" for "File:Example_image.svg".
 843                  *
 844                  * @return {string}
 845                  */
 846                 getMainText: function () {
 847                         return text( this.getMain() );
 848                 },
 849
 850                 /**
 851                  * Get the full page name
 852                  *
 853                  * Example: "File:Example_image.svg".
 854                  * Most useful for API calls, anything that must identify the "title".
 855                  *
 856                  * @return {string}
 857                  */
 858                 getPrefixedDb: function () {
 859                         return this.getNamespacePrefix() + this.getMain();
 860                 },
 861
 862                 /**
 863                  * Get the full page name (transformed by #text)
 864                  *
 865                  * Example: "File:Example image.svg" for "File:Example_image.svg".
 866                  *
 867                  * @return {string}
 868                  */
 869                 getPrefixedText: function () {
 870                         return text( this.getPrefixedDb() );
 871                 },
 872
 873                 /**
 874                  * Get the page name relative to a namespace
 875                  *
 876                  * Example:
 877                  *
 878                  * - "Foo:Bar" relative to the Foo namespace becomes "Bar".
 879                  * - "Bar" relative to any non-main namespace becomes ":Bar".
 880                  * - "Foo:Bar" relative to any namespace other than Foo stays "Foo:Bar".
 881                  *
 882                  * @param {number} namespace The namespace to be relative to
 883                  * @return {string}
 884                  */
 885                 getRelativeText: function ( namespace ) {
 886                         if ( this.getNamespaceId() === namespace ) {
 887                                 return this.getMainText();
 888                         } else if ( this.getNamespaceId() === NS_MAIN ) {
 889                                 return ':' + this.getPrefixedText();
 890                         } else {
 891                                 return this.getPrefixedText();
 892                         }
 893                 },
 894
 895                 /**
 896                  * Get the fragment (if any).
 897                  *
 898                  * Note that this method (by design) does not include the hash character and
 899                  * the value is not url encoded.
 900                  *
 901                  * @return {string|null}
 902                  */
 903                 getFragment: function () {
 904                         return this.fragment;
 905                 },
 906
 907                 /**
 908                  * Get the URL to this title
 909                  *
 910                  * @see mw.util#getUrl
 911                  * @param {Object} [params] A mapping of query parameter names to values,
 912                  *     e.g. `{ action: 'edit' }`.
 913                  * @return {string}
 914                  */
 915                 getUrl: function ( params ) {
 916                         return mw.util.getUrl( this.toString(), params );
 917                 },
 918
 919                 /**
 920                  * Whether this title exists on the wiki.
 921                  *
 922                  * @see #static-method-exists
 923                  * @return {boolean|null} Boolean if the information is available, otherwise null
 924                  */
 925                 exists: function () {
 926                         return Title.exists( this );
 927                 }
 928         };
 929
 930         /**
 931          * @alias #getPrefixedDb
 932          * @method
 933          */
 934         Title.prototype.toString = Title.prototype.getPrefixedDb;
 935
 936         /**
 937          * @alias #getPrefixedText
 938          * @method
 939          */
 940         Title.prototype.toText = Title.prototype.getPrefixedText;
 941
 942         // Expose
 943         mw.Title = Title;
 944
 945 }( mediaWiki, jQuery ) );