WordPress Admin Switcher Bookmark Source

wp-admin-switcher-bookmark-source.js

var WordPressAdminSwitcherBookmark = {};

/**
 * Switch to/from the WordPress Admin.
 */
WordPressAdminSwitcherBookmark.toggleAdmin = function() {
	if ( WordPressAdminSwitcherBookmark.isWordPressAdmin( window.location.pathname ) ) {
		WordPressAdminSwitcherBookmark.switchToFrontEnd();
	} else {
		WordPressAdminSwitcherBookmark.switchToAdmin();
	}
};

/**
 * Is this the WordPress admin?
 *
 * @param  {string} url    The URL to check.
 * @return {boolean}       Whether currently in the WordPress admin.
 */
WordPressAdminSwitcherBookmark.isWordPressAdmin = function( url ) {
	return ( url.indexOf( '/wp-admin/' ) > -1 ) || ( url.indexOf( '/wp-login.php' ) > -1 );
};

/**
 * Switch to the front end.
 */
WordPressAdminSwitcherBookmark.switchToFrontEnd = function() {
	WordPressAdminSwitcherBookmark.changeWindowLocation( WordPressAdminSwitcherBookmark.getFrontEndUrl() );
};

/**
 * Switch to the WP admin.
 */
WordPressAdminSwitcherBookmark.switchToAdmin = function() {
	WordPressAdminSwitcherBookmark.changeWindowLocation( WordPressAdminSwitcherBookmark.getAdminUrl() );
};

/**
 * Get frontend URL.
 *
 * @return {string} The frontend URL.
 */
WordPressAdminSwitcherBookmark.getFrontEndUrl = function() {

	var url = WordPressAdminSwitcherBookmark.getFrontEndUrlFromAdminBar();

	if ( url ) {
		return url;
	}

	url = WordPressAdminSwitcherBookmark.getFrontEndUrlFromWindowLocation();

	if ( url ) {
		return url;
	}

	// Return WordPressAdminSwitcherBookmark.as a last resort. Has the potential to
	// be incorrect on subdirectory multisite installs.
	return window.location.origin;
};

/**
 * Get front end URL from admin bar.
 *
 * Try to get the link to view/preview the post first,
 * then fallback to getting the main front end url.
 *
 * @return {string|boolean} The url or false on failure.
 */
WordPressAdminSwitcherBookmark.getFrontEndUrlFromAdminBar = function() {

	var adminBarIds = {
		view: '#wp-admin-bar-view',
		preview: '#wp-admin-bar-preview',
		siteName: '#wp-admin-bar-site-name'
	};

	return WordPressAdminSwitcherBookmark.getUrlFromAdminBar( adminBarIds );
};

/**
 * Get front end URL from window.location.
 *
 * @return {string|boolean} The url or false on failure.
 */
WordPressAdminSwitcherBookmark.getFrontEndUrlFromWindowLocation = function() {

	var adminUrlParts = {
		wpAdmin: '/wp-admin/',
		wpLogin: '/wp-login.php'
	};

	for ( var index in adminUrlParts ) {

		var adminUrlPartPosition = WordPressAdminSwitcherBookmark.getPositionOfStringInCurrentUrl( adminUrlParts[ index ] );

		if ( WordPressAdminSwitcherBookmark.doesUrlContainString( adminUrlPartPosition ) ) {
			return WordPressAdminSwitcherBookmark.getPartOfUrlBeforePosition( adminUrlPartPosition );
		}
	}

	return false;
};

/**
 * Get the position of a string in the current URL.
 *
 * @param  {string} string The string to find within the URL.
 * @return {number}        The position of string within the URL.
 */
WordPressAdminSwitcherBookmark.getPositionOfStringInCurrentUrl = function( string ) {
	return window.location.href.indexOf( string );
};

/**
 * Does the URL contain a string?
 *
 * @param  {number}  stringPosition The position of string within the URL.
 * @return {boolean}                Whether the URL contains the string.
 */
WordPressAdminSwitcherBookmark.doesUrlContainString = function( stringPosition ) {
	return WordPressAdminSwitcherBookmark.doesStringContainSubstring( stringPosition );
};

/**
 * Does string contain a substring?
 *
 * @param  {number} stringPosition The position of substring within the string.
 * @return {boolean}               Whether the substring was found within the string.
 */
WordPressAdminSwitcherBookmark.doesStringContainSubstring = function( stringPosition ) {
	return stringPosition > -1;
};

/**
 * Get part of URL before the provided position.
 *
 * @param  {number} stringPosition Exclude the character at WordPressAdminSwitcherBookmark.position and following.
 * @return {string}                The part of the URL before stringPosition.
 */
WordPressAdminSwitcherBookmark.getPartOfUrlBeforePosition = function( stringPosition ) {
	return window.location.href.substring( 0, stringPosition );
};

/**
 * Get the admin URL.
 *
 * @return {string} The admin URL.
 */
WordPressAdminSwitcherBookmark.getAdminUrl = function() {

	var url = WordPressAdminSwitcherBookmark.getAdminUrlFromAdminBar();

	if ( url ) {
		return url;
	}

	url = WordPressAdminSwitcherBookmark.getAdminUrlFromPageSource();

	if ( url ) {
		return url;
	}

	// Return WordPressAdminSwitcherBookmark.as a last resort. Has the potential to
	// be incorrect on subdirectory multisite installs.
	return WordPressAdminSwitcherBookmark.trailingSlashIt( window.location.origin ) + 'wp-admin/';
};

/**
 * Get admin URL from page source.
 *
 * @return {string|boolean} The admin URL or false on failure.
 */
WordPressAdminSwitcherBookmark.getAdminUrlFromPageSource = function() {

	var url    = WordPressAdminSwitcherBookmark.inferUrlFromPageLinks(),
		postId = WordPressAdminSwitcherBookmark.inferPostIdFromPageSource();

	if ( url ) {

		var adminUrl = WordPressAdminSwitcherBookmark.getAdminUrlFromSiteUrl( url );

		if ( postId ) {
			adminUrl = WordPressAdminSwitcherBookmark.getPostSpecificAdminUrl( adminUrl, postId );
		}

		return adminUrl;
	}

	return false;
};

/**
 * Turn site URL into admin URL.
 *
 * @param  {string} url The site URL.
 * @return {string}     The admin URL.
 */
WordPressAdminSwitcherBookmark.getAdminUrlFromSiteUrl = function( url ) {
	return WordPressAdminSwitcherBookmark.trailingSlashIt( url ) + 'wp-admin/';
};

/**
 * Turn base admin URL into a post-specific admin URL.
 *
 * @param  {string} adminUrl The base admin URL.
 * @param  {string} postId   The post ID.
 * @return {string}          The post-specific admin URL.
 */
WordPressAdminSwitcherBookmark.getPostSpecificAdminUrl = function( adminUrl, postId ) {
	return adminUrl + 'post.php?post=' + postId + '&action=edit';
};

/**
 * Get WP admin URL from the admin bar.
 *
 * @return {string|boolean} The URL or false on failure.
 */
WordPressAdminSwitcherBookmark.getAdminUrlFromAdminBar = function() {

	var adminBarIds = {
		edit: '#wp-admin-bar-edit',
		siteName: '#wp-admin-bar-site-name'
	};

	return WordPressAdminSwitcherBookmark.getUrlFromAdminBar( adminBarIds );
};

/**
 * Get URL from the WP admin bar.
 *
 * @param  {Object}         adminBarIds The element IDs to use as selectors.
 * @return {string|boolean}             The URL or false on failure.
 */
WordPressAdminSwitcherBookmark.getUrlFromAdminBar = function ( adminBarIds ) {

	if ( WordPressAdminSwitcherBookmark.isEmptyObject( adminBarIds ) ) {
		return false;
	}

	for ( var key in adminBarIds ) {

		var adminBarAnchorHtmlElement = WordPressAdminSwitcherBookmark.getAdminBarAnchorHtmlElement( adminBarIds[ key ] );

		if ( WordPressAdminSwitcherBookmark.wereHtmlElementsFound( adminBarAnchorHtmlElement ) ) {
			return WordPressAdminSwitcherBookmark.getHrefUrlFromHtmlElement( adminBarAnchorHtmlElement );
		}
	}

	return false;
};

/**
 * Is WordPressAdminSwitcherBookmark.an empty object?
 *
 * @param  {Object} object The object to check.
 * @return {boolean}       Whether the object is empty.
 */
WordPressAdminSwitcherBookmark.isEmptyObject = function( object ) {
	return ( Object != object.constructor ) || ( Object.keys( object ).length < 1 );
};

/**
 * Get admin bar anchor HTML element.
 *
 * @param  {string} adminBarId The id of the HTML element to get. 
 * @return {Object}            The matching HTML element NodeList.
 */
WordPressAdminSwitcherBookmark.getAdminBarAnchorHtmlElement = function( adminBarId ) {
	return document.querySelectorAll( adminBarId + ' > a.ab-item[href]' );
};

/**
 * Here any HTML elements found?
 *
 * @param  {Object}  nodelist The NodeList of HTML elements found.
 * @return {boolean}          Whether HTML elements were found.
 */
WordPressAdminSwitcherBookmark.wereHtmlElementsFound = function( nodelist ) {
	return nodelist.length > 0;
};

/**
 * Get the URL from an HTML element's href property.
 *
 * @param  {Object} element The HTML element NodeList.
 * @return {string}         The URL.
 */
WordPressAdminSwitcherBookmark.getHrefUrlFromHtmlElement = function( element ) {
	return element[0].getAttribute( 'href' );
};

/**
 * Infer the site's URL from links in the page source.
 *
 * We can't simply get the site's URL from window.location
 * because subdomain multisite installs need to have the
 * /site-name/ part of the pathname preserved.
 *
 * @return {string|boolean} The URL or false on failure.
 */
WordPressAdminSwitcherBookmark.inferUrlFromPageLinks = function() {

	var selectors = {
		stylesheets: 'link[rel="stylesheet"][href]',
		scripts: 'script[src]',
		rss: 'link[type="application/rss+xml"][href]',
		xmlrpc: 'link[rel="pingback"][href]'
	};

	for ( var selectorIndex in selectors ) {

		var elements = document.querySelectorAll( selectors[ selectorIndex ] );

		if ( WordPressAdminSwitcherBookmark.wereHtmlElementsFound( elements ) ) {

			for ( var elementIndex in elements ) {

				var attribute = WordPressAdminSwitcherBookmark.getAttributeForSelector( selectorIndex ),
					url       = WordPressAdminSwitcherBookmark.inferUrlFromPageLink( elements[ elementIndex ], attribute );

				if ( url ) {
					return url;
				}
			}
		}
	}

	return false;
};

/**
 * Extract the URL from an HTML element.
 *
 * @param  {Object}         element   The HTML element
 * @param  {string}         attribute The attribute to get the URL from: 'href' or 'src'.
 * @return {string|boolean}           The URL or false on failure.
 */
WordPressAdminSwitcherBookmark.inferUrlFromPageLink = function( element, attribute ) {

	var paths = {
		wpContent: '/wp-content/',
		wpIncludes: '/wp-includes/'
	};

	for ( var index in paths ) {

		var url = WordPressAdminSwitcherBookmark.getUrlSubstringFromHtmlElement( element, attribute, paths[ index ] );

		if ( url ) {
			return url;
		}
	}

	return false;
};

/**
 * Get the URL-containing attribute for a selector type.
 *
 * @param  {string} selector The selector type.
 * @return {string}          The attribute for contains the URL.
 */
WordPressAdminSwitcherBookmark.getAttributeForSelector = function( selector ) {

	switch ( selector ) {
		case 'scripts':
			return 'src';
		default:
			return 'href';
	}
};

/**
 * Extract part of a URL from an HTML element.
 *
 * @param  {Object}         element   The HTML element.
 * @param  {string}         attribute The attribute to get URL from ('href' or 'src').
 * @param  {string}         string    The text to search for and exclude, along with
 *                                    everything after it.
 * @return {string|boolean}           The part of the URL or false on failure.
 */
WordPressAdminSwitcherBookmark.getUrlSubstringFromHtmlElement = function( element, attribute, string ) {

	var stringPosition = element[ attribute ].indexOf( string );

	if ( WordPressAdminSwitcherBookmark.doesUrlContainString( stringPosition ) ) {
		return element[ attribute ].substring( 0, stringPosition );
	}

	return false;
};

/**
 * Infer post ID from the page source.
 *
 * Not all WordPress sites will have WordPressAdminSwitcherBookmark.exposed.
 *
 * @return {string|boolean} The post ID or false on failure.
 */
WordPressAdminSwitcherBookmark.inferPostIdFromPageSource = function() {

	var postId = false,
		postIdSelectors = {
		commentsForm: '#comment_post_ID[value]',
		shortlink: 'link[rel="shortlink"][href]',
		body: 'body[class]'

	};

	for ( var index in postIdSelectors ) {

		var postIdElement = document.querySelectorAll( postIdSelectors[ index ] );

		if ( ! WordPressAdminSwitcherBookmark.wereHtmlElementsFound( postIdElement ) ) {
			continue;
		}

		switch ( index ) {
			case 'commentsForm':
				postId = WordPressAdminSwitcherBookmark.getPostIdFromCommentsForm( postIdElement );
				break;
			case 'shortlink':
				postId = WordPressAdminSwitcherBookmark.getPostIdFromShortlink( postIdElement );
				break;
			case 'body':
				postId = WordPressAdminSwitcherBookmark.getPostIdFromBodyClass( postIdElement );
		}
	}

	return postId;
};

/**
 * Get post ID from comments form.
 *
 * @param  {Object} postIdElement The HTML element NodeList containing the post ID.
 * @return {string}               The post ID.
 */
WordPressAdminSwitcherBookmark.getPostIdFromCommentsForm = function( postIdElement ) {
	return postIdElement[0].value;
};

/**
 * Get post ID from shortlink.
 *
 * @param  {Object}         postIdElement The HTML element NodeList containing the post ID.
 * @return {string|boolean}               The post ID or false on failure.
 */
WordPressAdminSwitcherBookmark.getPostIdFromShortlink = function( postIdElement ) {

	var shortlinkUrl = WordPressAdminSwitcherBookmark.getHrefUrlFromHtmlElement( postIdElement );

	if ( ! WordPressAdminSwitcherBookmark.isShortlinkUsingWpMeService( shortlinkUrl ) ) {

		var positionOfUrlTextBeforePostId = WordPressAdminSwitcherBookmark.getPositionOfUrlTextBeforePostId( shortlinkUrl );

		if ( WordPressAdminSwitcherBookmark.doesShortlinkUrlContainPostId( positionOfUrlTextBeforePostId ) ) {
			return WordPressAdminSwitcherBookmark.getPostIdFromShortlinkUrl( shortlinkUrl, positionOfUrlTextBeforePostId );
		}
	}

	return false;
};

/**
 * Is shortlink using wp.me service?
 *
 * @param  {string}  shortlinkUrl The shortlink URL.
 * @return {boolean}              Whether shorlinkUrl is using wp.me.
 */
WordPressAdminSwitcherBookmark.isShortlinkUsingWpMeService = function( shortlinkUrl ) {
	return shortlinkUrl.indexOf( '//wp.me/' ) > -1;
};

/**
 * Get the position of the URL before the post ID.
 *
 * @param  {string} shortlinkUrl The URL to search.
 * @return {number}              The position of the post ID.
 */
WordPressAdminSwitcherBookmark.getPositionOfUrlTextBeforePostId = function( shortlinkUrl ) {
	return shortlinkUrl.indexOf( '/?p=' );
};

/**
 * Does the shortlink URL contain the post ID?
 *
 * @param  {number}  positionOfUrlTextBeforePostId The position of the URL text before the post ID.
 * @return {boolean}                               Whether the URL contains the post ID.
 */
WordPressAdminSwitcherBookmark.doesShortlinkUrlContainPostId = function( positionOfUrlTextBeforePostId ) {
	return WordPressAdminSwitcherBookmark.doesStringContainSubstring( positionOfUrlTextBeforePostId );
};

/**
 * Extract the post ID from the shortlink URL.
 *
 * @param  {string} shortlinkUrl                  The shortlink URL.
 * @param  {number} positionOfUrlTextBeforePostId The position of URL text before the post ID.
 * @return {string}                               The post ID.
 */
WordPressAdminSwitcherBookmark.getPostIdFromShortlinkUrl = function( shortlinkUrl, positionOfUrlTextBeforePostId ) {
	return shortlinkUrl.substring( positionOfUrlTextBeforePostId + 4, shortlinkUrl.length );
};

/**
 * Get post ID from body class.
 *
 * @param  {Object}         postIdElement The HTML element NodeList containing the post ID.
 * @return {string|boolean}               The post ID or false on failure.
 */
WordPressAdminSwitcherBookmark.getPostIdFromBodyClass = function( postIdElement ) {

	var bodyClasses    = postIdElement[0].getAttribute( 'class' ),
		postIdPosition = bodyClasses.indexOf( 'postid-' );

	if ( WordPressAdminSwitcherBookmark.doesStringContainSubstring( postIdPosition ) ) {
		bodyClasses = bodyClasses.substring( postIdPosition + 7, bodyClasses.length );

		var firstSpacePosition = bodyClasses.indexOf( ' ' );

		if ( WordPressAdminSwitcherBookmark.doesStringContainSubstring( firstSpacePosition ) ) {
			return bodyClasses.substring( 0, firstSpacePosition );
		}

		return bodyClasses;
	}

	return false;
};

/**
 * Add a trailing slash to a URL if it doesn't already have one.
 *
 * @param  {string} url The URL.
 * @return {string} url The URL with a trailing slash.
 */
WordPressAdminSwitcherBookmark.trailingSlashIt = function( url ) {

	if ( ! url.endsWith( '/' ) ) {
		url += '/';
	}

	return url;
};

/**
 * Change the window location.
 *
 * @param {string} url The URL to set as the new location.
 */
WordPressAdminSwitcherBookmark.changeWindowLocation = function( url ) {
	window.location = url;
};

WordPressAdminSwitcherBookmark.toggleAdmin();