path: root/resources/src/mediawiki/mediawiki.Title.js

/*!
 * @author Neil Kandalgaonkar, 2010
 * @author Timo Tijhof, 2011-2013
 * @since 1.18
 */
( function ( mw, $ ) {

	/**
	 * @class mw.Title
	 *
	 * Parse titles into an object structure. Note that when using the constructor
	 * directly, passing invalid titles will result in an exception. Use #newFromText to use the
	 * logic directly and get null for invalid titles which is easier to work with.
	 *
	 * @constructor
	 * @param {string} title Title of the page. If no second argument given,
	 *  this will be searched for a namespace
	 * @param {number} [namespace=NS_MAIN] If given, will used as default namespace for the given title
	 * @throws {Error} When the title is invalid
	 */
	function Title( title, namespace ) {
		var parsed = parse( title, namespace );
		if ( !parsed ) {
			throw new Error( 'Unable to parse title' );
		}

		this.namespace = parsed.namespace;
		this.title = parsed.title;
		this.ext = parsed.ext;
		this.fragment = parsed.fragment;

		return this;
	}

	/* Private members */

	var

	/**
	 * @private
	 * @static
	 * @property NS_MAIN
	 */
	NS_MAIN = 0,

	/**
	 * @private
	 * @static
	 * @property NS_TALK
	 */
	NS_TALK = 1,

	/**
	 * @private
	 * @static
	 * @property NS_SPECIAL
	 */
	NS_SPECIAL = -1,

	/**
	 * @private
	 * @static
	 * @property NS_MEDIA
	 */
	NS_MEDIA = -2,

	/**
	 * @private
	 * @static
	 * @property NS_FILE
	 */
	NS_FILE = 6,

	/**
	 * @private
	 * @static
	 * @property FILENAME_MAX_BYTES
	 */
	FILENAME_MAX_BYTES = 240,

	/**
	 * @private
	 * @static
	 * @property TITLE_MAX_BYTES
	 */
	TITLE_MAX_BYTES = 255,

	/**
	 * Get the namespace id from a namespace name (either from the localized, canonical or alias
	 * name).
	 *
	 * Example: On a German wiki this would return 6 for any of 'File', 'Datei', 'Image' or
	 * even 'Bild'.
	 *
	 * @private
	 * @static
	 * @method getNsIdByName
	 * @param {string} ns Namespace name (case insensitive, leading/trailing space ignored)
	 * @return {number|boolean} Namespace id or boolean false
	 */
	getNsIdByName = function ( ns ) {
		var id;

		// Don't cast non-strings to strings, because null or undefined should not result in
		// returning the id of a potential namespace called "Null:" (e.g. on null.example.org/wiki)
		// Also, toLowerCase throws exception on null/undefined, because it is a String method.
		if ( typeof ns !== 'string' ) {
			return false;
		}
		ns = ns.toLowerCase();
		id = mw.config.get( 'wgNamespaceIds' )[ns];
		if ( id === undefined ) {
			return false;
		}
		return id;
	},

	rUnderscoreTrim = /^_+|_+$/g,

	rSplit = /^(.+?)_*:_*(.*)$/,

	// See MediaWikiTitleCodec.php#getTitleInvalidRegex
	rInvalid = new RegExp(
		'[^' + mw.config.get( 'wgLegalTitleChars' ) + ']' +
		// URL percent encoding sequences interfere with the ability
		// to round-trip titles -- you can't link to them consistently.
		'|%[0-9A-Fa-f]{2}' +
		// XML/HTML character references produce similar issues.
		'|&[A-Za-z0-9\u0080-\uFFFF]+;' +
		'|&#[0-9]+;' +
		'|&#x[0-9A-Fa-f]+;'
	),

	// From MediaWikiTitleCodec.php#L225 @26fcab1f18c568a41
	// "Clean up whitespace" in function MediaWikiTitleCodec::splitTitleString()
	rWhitespace = /[ _\u0009\u00A0\u1680\u180E\u2000-\u200A\u2028\u2029\u202F\u205F\u3000\s]+/g,

	/**
	 * Slightly modified from Flinfo. Credit goes to Lupo and Flominator.
	 * @private
	 * @static
	 * @property sanitationRules
	 */
	sanitationRules = [
		// "signature"
		{
			pattern: /~{3}/g,
			replace: '',
			generalRule: true
		},
		// Space, underscore, tab, NBSP and other unusual spaces
		{
			pattern: rWhitespace,
			replace: ' ',
			generalRule: true
		},
		// unicode bidi override characters: Implicit, Embeds, Overrides
		{
			pattern: /[\u200E\u200F\u202A-\u202E]/g,
			replace: '',
			generalRule: true
		},
		// control characters
		{
			pattern: /[\x00-\x1f\x7f]/g,
			replace: '',
			generalRule: true
		},
		// URL encoding (possibly)
		{
			pattern: /%([0-9A-Fa-f]{2})/g,
			replace: '% $1',
			generalRule: true
		},
		// HTML-character-entities
		{
			pattern: /&(([A-Za-z0-9\x80-\xff]+|#[0-9]+|#x[0-9A-Fa-f]+);)/g,
			replace: '& $1',
			generalRule: true
		},
		// slash, colon (not supported by file systems like NTFS/Windows, Mac OS 9 [:], ext4 [/])
		{
			pattern: /[:\/#]/g,
			replace: '-',
			fileRule: true
		},
		// brackets, greater than
		{
			pattern: /[\]\}>]/g,
			replace: ')',
			generalRule: true
		},
		// brackets, lower than
		{
			pattern: /[\[\{<]/g,
			replace: '(',
			generalRule: true
		},
		// everything that wasn't covered yet
		{
			pattern: new RegExp( rInvalid.source, 'g' ),
			replace: '-',
			generalRule: true
		},
		// directory structures
		{
			pattern: /^(\.|\.\.|\.\/.*|\.\.\/.*|.*\/\.\/.*|.*\/\.\.\/.*|.*\/\.|.*\/\.\.)$/g,
			replace: '',
			generalRule: true
		}
	],

	/**
	 * Internal helper for #constructor and #newFromtext.
	 *
	 * Based on Title.php#secureAndSplit
	 *
	 * @private
	 * @static
	 * @method parse
	 * @param {string} title
	 * @param {number} [defaultNamespace=NS_MAIN]
	 * @return {Object|boolean}
	 */
	parse = function ( title, defaultNamespace ) {
		var namespace, m, id, i, fragment, ext;

		namespace = defaultNamespace === undefined ? NS_MAIN : defaultNamespace;

		title = title
			// Normalise whitespace to underscores and remove duplicates
			.replace( /[ _\s]+/g, '_' )
			// Trim underscores
			.replace( rUnderscoreTrim, '' );

		// Process initial colon
		if ( title !== '' && title.charAt( 0 ) === ':' ) {
			// Initial colon means main namespace instead of specified default
			namespace = NS_MAIN;
			title = title
				// Strip colon
				.slice( 1 )
				// Trim underscores
				.replace( rUnderscoreTrim, '' );
		}

		if ( title === '' ) {
			return false;
		}

		// Process namespace prefix (if any)
		m = title.match( rSplit );
		if ( m ) {
			id = getNsIdByName( m[1] );
			if ( id !== false ) {
				// Ordinary namespace
				namespace = id;
				title = m[2];

				// For Talk:X pages, make sure X has no "namespace" prefix
				if ( namespace === NS_TALK && ( m = title.match( rSplit ) ) ) {
					// Disallow titles like Talk:File:x (subject should roundtrip: talk:file:x -> file:x -> file_talk:x)
					if ( getNsIdByName( m[1] ) !== false ) {
						return false;
					}
				}
			}
		}

		// Process fragment
		i = title.indexOf( '#' );
		if ( i === -1 ) {
			fragment = null;
		} else {
			fragment = title
				// Get segment starting after the hash
				.slice( i + 1 )
				// Convert to text
				// NB: Must not be trimmed ("Example#_foo" is not the same as "Example#foo")
				.replace( /_/g, ' ' );

			title = title
				// Strip hash
				.slice( 0, i )
				// Trim underscores, again (strips "_" from "bar" in "Foo_bar_#quux")
				.replace( rUnderscoreTrim, '' );
		}

		// Reject illegal characters
		if ( title.match( rInvalid ) ) {
			return false;
		}

		// Disallow titles that browsers or servers might resolve as directory navigation
		if (
			title.indexOf( '.' ) !== -1 && (
				title === '.' || title === '..' ||
				title.indexOf( './' ) === 0 ||
				title.indexOf( '../' ) === 0 ||
				title.indexOf( '/./' ) !== -1 ||
				title.indexOf( '/../' ) !== -1 ||
				title.slice( -2 ) === '/.' ||
				title.slice( -3 ) === '/..'
			)
		) {
			return false;
		}

		// Disallow magic tilde sequence
		if ( title.indexOf( '~~~' ) !== -1 ) {
			return false;
		}

		// Disallow titles exceeding the TITLE_MAX_BYTES byte size limit (size of underlying database field)
		// Except for special pages, e.g. [[Special:Block/Long name]]
		// Note: The PHP implementation also asserts that even in NS_SPECIAL, the title should
		// be less than 512 bytes.
		if ( namespace !== NS_SPECIAL && $.byteLength( title ) > TITLE_MAX_BYTES ) {
			return false;
		}

		// Can't make a link to a namespace alone.
		if ( title === '' && namespace !== NS_MAIN ) {
			return false;
		}

		// Any remaining initial :s are illegal.
		if ( title.charAt( 0 ) === ':' ) {
			return false;
		}

		// For backwards-compatibility with old mw.Title, we separate the extension from the
		// rest of the title.
		i = title.lastIndexOf( '.' );
		if ( i === -1 || title.length <= i + 1 ) {
			// Extensions are the non-empty segment after the last dot
			ext = null;
		} else {
			ext = title.slice( i + 1 );
			title = title.slice( 0, i );
		}

		return {
			namespace: namespace,
			title: title,
			ext: ext,
			fragment: fragment
		};
	},

	/**
	 * Convert db-key to readable text.
	 *
	 * @private
	 * @static
	 * @method text
	 * @param {string} s
	 * @return {string}
	 */
	text = function ( s ) {
		if ( s !== null && s !== undefined ) {
			return s.replace( /_/g, ' ' );
		} else {
			return '';
		}
	},

	/**
	 * Sanitizes a string based on a rule set and a filter
	 *
	 * @private
	 * @static
	 * @method sanitize
	 * @param {string} s
	 * @param {Array} filter
	 * @return {string}
	 */
	sanitize = function ( s, filter ) {
		var i, ruleLength, rule, m, filterLength,
			rules = sanitationRules;

		for ( i = 0, ruleLength = rules.length; i < ruleLength; ++i ) {
			rule = rules[i];
			for ( m = 0, filterLength = filter.length; m < filterLength; ++m ) {
				if ( rule[filter[m]] ) {
					s = s.replace( rule.pattern, rule.replace );
				}
			}
		}
		return s;
	},

	/**
	 * Cuts a string to a specific byte length, assuming UTF-8
	 * or less, if the last character is a multi-byte one
	 *
	 * @private
	 * @static
	 * @method trimToByteLength
	 * @param {string} s
	 * @param {number} length
	 * @return {string}
	 */
	trimToByteLength = function ( s, length ) {
		var byteLength, chopOffChars, chopOffBytes;

		// bytelength is always greater or equal to the length in characters
		s = s.substr( 0, length );
		while ( ( byteLength = $.byteLength( s ) ) > length ) {
			// Calculate how many characters can be safely removed
			// First, we need to know how many bytes the string exceeds the threshold
			chopOffBytes = byteLength - length;
			// A character in UTF-8 is at most 4 bytes
			// One character must be removed in any case because the
			// string is too long
			chopOffChars = Math.max( 1, Math.floor( chopOffBytes / 4 ) );
			s = s.substr( 0, s.length - chopOffChars );
		}
		return s;
	},

	/**
	 * Cuts a file name to a specific byte length
	 *
	 * @private
	 * @static
	 * @method trimFileNameToByteLength
	 * @param {string} name without extension
	 * @param {string} extension file extension
	 * @return {string} The full name, including extension
	 */
	trimFileNameToByteLength = function ( name, extension ) {
		// There is a special byte limit for file names and ... remember the dot
		return trimToByteLength( name, FILENAME_MAX_BYTES - extension.length - 1 ) + '.' + extension;
	},

	// Polyfill for ES5 Object.create
	createObject = Object.create || ( function () {
		return function ( o ) {
			function Title() {}
			if ( o !== Object( o ) ) {
				throw new Error( 'Cannot inherit from a non-object' );
			}
			Title.prototype = o;
			return new Title();
		};
	}() );

	/* Static members */

	/**
	 * Constructor for Title objects with a null return instead of an exception for invalid titles.
	 *
	 * @static
	 * @param {string} title
	 * @param {number} [namespace=NS_MAIN] Default namespace
	 * @return {mw.Title|null} A valid Title object or null if the title is invalid
	 */
	Title.newFromText = function ( title, namespace ) {
		var t, parsed = parse( title, namespace );
		if ( !parsed ) {
			return null;
		}

		t = createObject( Title.prototype );
		t.namespace = parsed.namespace;
		t.title = parsed.title;
		t.ext = parsed.ext;
		t.fragment = parsed.fragment;

		return t;
	};

	/**
	 * Constructor for Title objects from user input altering that input to
	 * produce a title that MediaWiki will accept as legal
	 *
	 * @static
	 * @param {string} title
	 * @param {number} [defaultNamespace=NS_MAIN]
	 *  If given, will used as default namespace for the given title.
	 * @param {Object} [options] additional options
	 * @param {string} [options.fileExtension='']
	 *  If the title is about to be created for the Media or File namespace,
	 *  ensures the resulting Title has the correct extension. Useful, for example
	 *  on systems that predict the type by content-sniffing, not by file extension.
	 *  If different from empty string, `forUploading` is assumed.
	 * @param {boolean} [options.forUploading=true]
	 *  Makes sure that a file is uploadable under the title returned.
	 *  There are pages in the file namespace under which file upload is impossible.
	 *  Automatically assumed if the title is created in the Media namespace.
	 * @return {mw.Title|null} A valid Title object or null if the input cannot be turned into a valid title
	 */
	Title.newFromUserInput = function ( title, defaultNamespace, options ) {
		var namespace, m, id, ext, parts, normalizeExtension;

		// defaultNamespace is optional; check whether options moves up
		if ( arguments.length < 3 && $.type( defaultNamespace ) === 'object' ) {
			options = defaultNamespace;
			defaultNamespace = undefined;
		}

		// merge options into defaults
		options = $.extend( {
			fileExtension: '',
			forUploading: true
		}, options );

		normalizeExtension = function ( extension ) {
			// Remove only trailing space (that is removed by MW anyway)
			extension = extension.toLowerCase().replace( /\s*$/, '' );
			return extension;
		};

		namespace = defaultNamespace === undefined ? NS_MAIN : defaultNamespace;

		// Normalise whitespace and remove duplicates
		title = $.trim( title.replace( rWhitespace, ' ' ) );

		// Process initial colon
		if ( title !== '' && title.charAt( 0 ) === ':' ) {
			// Initial colon means main namespace instead of specified default
			namespace = NS_MAIN;
			title = title
				// Strip colon
				.substr( 1 )
				// Trim underscores
				.replace( rUnderscoreTrim, '' );
		}

		// Process namespace prefix (if any)
		m = title.match( rSplit );
		if ( m ) {
			id = getNsIdByName( m[1] );
			if ( id !== false ) {
				// Ordinary namespace
				namespace = id;
				title = m[2];
			}
		}

		if ( namespace === NS_MEDIA
			|| ( ( options.forUploading || options.fileExtension ) && ( namespace === NS_FILE ) )
		) {

			title = sanitize( title, [ 'generalRule', 'fileRule' ] );

			// Operate on the file extension
			// Although it is possible having spaces between the name and the ".ext" this isn't nice for
			// operating systems hiding file extensions -> strip them later on
			parts = title.split( '.' );

			if ( parts.length > 1 ) {

				// Get the last part, which is supposed to be the file extension
				ext = parts.pop();

				// Does the supplied file name carry the desired file extension?
				if ( options.fileExtension
					&& normalizeExtension( ext ) !== normalizeExtension( options.fileExtension )
				) {

					// No, push back, whatever there was after the dot
					parts.push( ext );

					// And add the desired file extension later
					ext = options.fileExtension;
				}

				// Remove whitespace of the name part (that W/O extension)
				title = $.trim( parts.join( '.' ) );

				// Cut, if too long and append file extension
				title = trimFileNameToByteLength( title, ext );

			} else {

				// Missing file extension
				title = $.trim( parts.join( '.' ) );

				if ( options.fileExtension ) {

					// Cut, if too long and append the desired file extension
					title = trimFileNameToByteLength( title, options.fileExtension );

				} else {

					// Name has no file extension and a fallback wasn't provided either
					return null;
				}
			}
		} else {

			title = sanitize( title, [ 'generalRule' ] );

			// Cut titles exceeding the TITLE_MAX_BYTES byte size limit
			// (size of underlying database field)
			if ( namespace !== NS_SPECIAL ) {
				title = trimToByteLength( title, TITLE_MAX_BYTES );
			}
		}

		// Any remaining initial :s are illegal.
		title = title.replace( /^\:+/, '' );

		return Title.newFromText( title, namespace );
	};

	/**
	 * Sanitizes a file name as supplied by the user, originating in the user's file system
	 * so it is most likely a valid MediaWiki title and file name after processing.
	 * Returns null on fatal errors.
	 *
	 * @static
	 * @param {string} uncleanName The unclean file name including file extension but
	 *   without namespace
	 * @param {string} [fileExtension] the desired file extension
	 * @return {mw.Title|null} A valid Title object or null if the title is invalid
	 */
	Title.newFromFileName = function ( uncleanName, fileExtension ) {

		return Title.newFromUserInput( 'File:' + uncleanName, {
			fileExtension: fileExtension,
			forUploading: true
		} );
	};

	/**
	 * Get the file title from an image element
	 *
	 *     var title = mw.Title.newFromImg( $( 'img:first' ) );
	 *
	 * @static
	 * @param {HTMLElement|jQuery} img The image to use as a base
	 * @return {mw.Title|null} The file title or null if unsuccessful
	 */
	Title.newFromImg = function ( img ) {
		var matches, i, regex, src, decodedSrc,

			// thumb.php-generated thumbnails
			thumbPhpRegex = /thumb\.php/,
			regexes = [
				// Thumbnails
				/\/[a-f0-9]\/[a-f0-9]{2}\/([^\s\/]+)\/[^\s\/]+-(?:\1|thumbnail)[^\s\/]*$/,

				// Thumbnails in non-hashed upload directories
				/\/([^\s\/]+)\/[^\s\/]+-(?:\1|thumbnail)[^\s\/]*$/,

				// Full size images
				/\/[a-f0-9]\/[a-f0-9]{2}\/([^\s\/]+)$/,

				// Full-size images in non-hashed upload directories
				/\/([^\s\/]+)$/
			],

			recount = regexes.length;

		src = img.jquery ? img[0].src : img.src;

		matches = src.match( thumbPhpRegex );

		if ( matches ) {
			return mw.Title.newFromText( 'File:' + mw.util.getParamValue( 'f', src ) );
		}

		decodedSrc = decodeURIComponent( src );

		for ( i = 0; i < recount; i++ ) {
			regex = regexes[i];
			matches = decodedSrc.match( regex );

			if ( matches && matches[1] ) {
				return mw.Title.newFromText( 'File:' + matches[1] );
			}
		}

		return null;
	};

	/**
	 * Whether this title exists on the wiki.
	 *
	 * @static
	 * @param {string|mw.Title} title prefixed db-key name (string) or instance of Title
	 * @return {boolean|null} Boolean if the information is available, otherwise null
	 */
	Title.exists = function ( title ) {
		var match,
			type = $.type( title ),
			obj = Title.exist.pages;

		if ( type === 'string' ) {
			match = obj[title];
		} else if ( type === 'object' && title instanceof Title ) {
			match = obj[title.toString()];
		} else {
			throw new Error( 'mw.Title.exists: title must be a string or an instance of Title' );
		}

		if ( typeof match === 'boolean' ) {
			return match;
		}

		return null;
	};

	/**
	 * Store page existence
	 *
	 * @static
	 * @property {Object} exist
	 * @property {Object} exist.pages Keyed by title. Boolean true value indicates page does exist.
	 *
	 * @property {Function} exist.set The setter function.
	 *
	 *  Example to declare existing titles:
	 *
	 *     Title.exist.set( ['User:John_Doe', ...] );
	 *
	 *  Example to declare titles nonexistent:
	 *
	 *     Title.exist.set( ['File:Foo_bar.jpg', ...], false );
	 *
	 * @property {string|Array} exist.set.titles Title(s) in strict prefixedDb title form
	 * @property {boolean} [exist.set.state=true] State of the given titles
	 * @return {boolean}
	 */
	Title.exist = {
		pages: {},

		set: function ( titles, state ) {
			titles = $.isArray( titles ) ? titles : [titles];
			state = state === undefined ? true : !!state;
			var i,
				pages = this.pages,
				len = titles.length;

			for ( i = 0; i < len; i++ ) {
				pages[ titles[i] ] = state;
			}
			return true;
		}
	};

	/* Public members */

	Title.prototype = {
		constructor: Title,

		/**
		 * Get the namespace number
		 *
		 * Example: 6 for "File:Example_image.svg".
		 *
		 * @return {number}
		 */
		getNamespaceId: function () {
			return this.namespace;
		},

		/**
		 * Get the namespace prefix (in the content language)
		 *
		 * Example: "File:" for "File:Example_image.svg".
		 * In #NS_MAIN this is '', otherwise namespace name plus ':'
		 *
		 * @return {string}
		 */
		getNamespacePrefix: function () {
			return this.namespace === NS_MAIN ?
				'' :
				( mw.config.get( 'wgFormattedNamespaces' )[ this.namespace ].replace( / /g, '_' ) + ':' );
		},

		/**
		 * Get the page name without extension or namespace prefix
		 *
		 * Example: "Example_image" for "File:Example_image.svg".
		 *
		 * For the page title (full page name without namespace prefix), see #getMain.
		 *
		 * @return {string}
		 */
		getName: function () {
			if ( $.inArray( this.namespace, mw.config.get( 'wgCaseSensitiveNamespaces' ) ) !== -1 ) {
				return this.title;
			} else {
				return $.ucFirst( this.title );
			}
		},

		/**
		 * Get the page name (transformed by #text)
		 *
		 * Example: "Example image" for "File:Example_image.svg".
		 *
		 * For the page title (full page name without namespace prefix), see #getMainText.
		 *
		 * @return {string}
		 */
		getNameText: function () {
			return text( this.getName() );
		},

		/**
		 * Get the extension of the page name (if any)
		 *
		 * @return {string|null} Name extension or null if there is none
		 */
		getExtension: function () {
			return this.ext;
		},

		/**
		 * Shortcut for appendable string to form the main page name.
		 *
		 * Returns a string like ".json", or "" if no extension.
		 *
		 * @return {string}
		 */
		getDotExtension: function () {
			return this.ext === null ? '' : '.' + this.ext;
		},

		/**
		 * Get the main page name
		 *
		 * Example: "Example_image.svg" for "File:Example_image.svg".
		 *
		 * @return {string}
		 */
		getMain: function () {
			return this.getName() + this.getDotExtension();
		},

		/**
		 * Get the main page name (transformed by #text)
		 *
		 * Example: "Example image.svg" for "File:Example_image.svg".
		 *
		 * @return {string}
		 */
		getMainText: function () {
			return text( this.getMain() );
		},

		/**
		 * Get the full page name
		 *
		 * Example: "File:Example_image.svg".
		 * Most useful for API calls, anything that must identify the "title".
		 *
		 * @return {string}
		 */
		getPrefixedDb: function () {
			return this.getNamespacePrefix() + this.getMain();
		},

		/**
		 * Get the full page name (transformed by #text)
		 *
		 * Example: "File:Example image.svg" for "File:Example_image.svg".
		 *
		 * @return {string}
		 */
		getPrefixedText: function () {
			return text( this.getPrefixedDb() );
		},

		/**
		 * Get the page name relative to a namespace
		 *
		 * Example:
		 *
		 * - "Foo:Bar" relative to the Foo namespace becomes "Bar".
		 * - "Bar" relative to any non-main namespace becomes ":Bar".
		 * - "Foo:Bar" relative to any namespace other than Foo stays "Foo:Bar".
		 *
		 * @param {number} namespace The namespace to be relative to
		 * @return {string}
		 */
		getRelativeText: function ( namespace ) {
			if ( this.getNamespaceId() === namespace ) {
				return this.getMainText();
			} else if ( this.getNamespaceId() === NS_MAIN ) {
				return ':' + this.getPrefixedText();
			} else {
				return this.getPrefixedText();
			}
		},

		/**
		 * Get the fragment (if any).
		 *
		 * Note that this method (by design) does not include the hash character and
		 * the value is not url encoded.
		 *
		 * @return {string|null}
		 */
		getFragment: function () {
			return this.fragment;
		},

		/**
		 * Get the URL to this title
		 *
		 * @see mw.util#getUrl
		 * @param {Object} [params] A mapping of query parameter names to values,
		 *     e.g. `{ action: 'edit' }`.
		 * @return {string}
		 */
		getUrl: function ( params ) {
			return mw.util.getUrl( this.toString(), params );
		},

		/**
		 * Whether this title exists on the wiki.
		 *
		 * @see #static-method-exists
		 * @return {boolean|null} Boolean if the information is available, otherwise null
		 */
		exists: function () {
			return Title.exists( this );
		}
	};

	/**
	 * @alias #getPrefixedDb
	 * @method
	 */
	Title.prototype.toString = Title.prototype.getPrefixedDb;

	/**
	 * @alias #getPrefixedText
	 * @method
	 */
	Title.prototype.toText = Title.prototype.getPrefixedText;

	// Expose
	mw.Title = Title;

}( mediaWiki, jQuery ) );