/* * This file is part of the MediaWiki extension MediaViewer. * * MediaViewer is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * MediaViewer is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with MediaViewer. If not, see . */ ( function () { var HUP, cache; /** * Shared cache between HtmlUtils instances to store the results of expensive text operations. * * @member mw.mmv.HtmlUtils * @private * @static * @type {{text: Object., textWithLinks: Object., textWithTags: Object.}} */ cache = { text: {}, textWithLinks: {}, textWithTags: {} }; /** * Helper class that does various HTML-to-text transformations * * @class mw.mmv.HtmlUtils * @constructor */ function HtmlUtils() {} HUP = HtmlUtils.prototype; /** * Returns a jQuery node which contains the given HTML (wrapped into a `
` - this is * necessary since an arbitrary HTML string might not have a jQuery representation). * * @param {string|HTMLElement|jQuery} html * @return {jQuery} */ HUP.wrapAndJquerify = function ( html ) { if ( this.isJQueryOrHTMLElement( html ) ) { return $( '
' ).append( $( html ).clone() ); } else if ( typeof html === 'string' ) { return $( '
' ).html( html ); } else { mw.log.warn( 'wrapAndJquerify: unknown type', html ); throw new Error( 'wrapAndJquerify: unknown type' ); } }; /** * Returns true of the object is a jQuery object or an HTMLElement, false otherwise * * @param {string|HTMLElement|jQuery} html * @return {boolean} */ HUP.isJQueryOrHTMLElement = function ( html ) { if ( html instanceof $ ) { return true; } if ( window.HTMLElement ) { if ( html instanceof HTMLElement ) { return true; } } return false; }; /** * Filters display:none and children of a node. * The root element is never filtered, and generally ignored (i.e. whether the root element is * visible won't affect the filtering). * Works in place. * * @param {jQuery} $jq */ HUP.filterInvisible = function ( $jq ) { // We are not using :visible because // 1) it would require appending $jq to the document which makes things complicated; // 2) the main difference is that it looks for CSS rules hiding the element; // since this function is intended to be used on html originating from a different // document, possibly a different site, that would probably have unexpected results. $jq .find( '[style]' ) .filter( function () { return this.style.display === 'none'; } ) .remove(); // TemplateStyles can generate inline style tags $jq .find( 'style' ) .remove(); }; /** * Discards all nodes which do not match the whitelist, * but keeps the text and whitelisted nodes inside them. * Works in-place. * * @param {jQuery} $el * @param {string} whitelist a jQuery selector string such as 'a, span, br' */ HUP.whitelistHtml = function ( $el, whitelist ) { var child, $prev, $child = $el.children().first(); while ( $child && $child.length ) { child = $child.get( 0 ); if ( child.nodeType !== child.ELEMENT_NODE ) { return; } this.whitelistHtml( $child, whitelist ); if ( !$child.is( whitelist ) ) { $prev = $child.prev(); $child.replaceWith( $child.contents() ); } else { $prev = $child; } if ( $prev && $prev.length === 1 ) { $child = $prev.next(); } else { $child = $el.children().first(); } } }; /** * Adds a whitespace to block elements. This is useful if you want to convert the contents * to text and don't want words that are visually separate (e.g. table cells) to be fused. * Works in-place. * * @param {jQuery} $el */ HUP.appendWhitespaceToBlockElements = function ( $el ) { // the list of what elements to add whitespace to is somewhat ad-hoc (not all of these // are technically block-level elements, and a lot of block-level elements are missing) // but will hopefully cover the common cases where text is fused together. $el .find( 'blockquote, dd, dl, dt, li, td' ) .before( ' ' ) .after( ' ' ); $el .find( 'br, tr, p' ) .before( '\n' ) .after( '\n' ); }; /** * Returns the HTML code for a jQuery element (only the first one if passed a set of elements). * Unlike .html(), this includes HTML code for the outermost element; compare * - `$('
').html() // ''` * - `mw.mmv.HtmlUtils.jqueryToHtml( $('
') ) // '
'` * * @param {jQuery} $el * @return {string} */ HUP.jqueryToHtml = function ( $el ) { // There are two possible implementations for this: // 1) load into a wrapper element and get its innerHTML; // 2) use outerHTML. // We go with 1) because it handles the case when a jQuery object contains something // that is not an element (this can happen with e.g. $x.children() which returns text // nodes as well). return $( '
' ).append( $el ).html(); }; /** * Cleans up superfluous whitespace. * Given that the results will be displayed in a HTML environment, this doesn't have any real * effect. It is mostly there to make testing easier. * * @protected * @param {string} html a HTML (or plaintext) string * @return {string} */ HUP.mergeWhitespace = function ( html ) { html = html.replace( /^\s+|\s+$/g, '' ); html = html.replace( /\s*\n\s*/g, '\n' ); html = html.replace( / {2,}/g, ' ' ); return html; }; /** * Returns the text content of a html string. * Tries to give an approximation of what would be visible if the HTML would be displayed. * * @param {string} html * @return {string} */ HUP.htmlToText = function ( html ) { var $html; if ( !cache.text[ html ] ) { $html = this.wrapAndJquerify( html ); this.filterInvisible( $html ); this.appendWhitespaceToBlockElements( $html ); cache.text[ html ] = this.mergeWhitespace( $html.text() ); } return cache.text[ html ]; }; /** * Returns the text content of a html string, with the ``, ``, `` tags left intact. * Tries to give an approximation of what would be visible if the HTML would be displayed. * * @param {string} html * @return {string} */ HUP.htmlToTextWithTags = function ( html ) { var $html; if ( !cache.textWithTags[ html ] ) { $html = this.wrapAndJquerify( html ); this.filterInvisible( $html ); this.appendWhitespaceToBlockElements( $html ); this.whitelistHtml( $html, 'a, span, i, b, sup, sub' ); cache.textWithTags[ html ] = this.mergeWhitespace( $html.html() ); } return cache.textWithTags[ html ]; }; /** * Returns the text content of a html string, with the `` tags left intact. * Tries to give an approximation of what would be visible if the HTML would be displayed. * * @param {string} html * @return {string} */ HUP.htmlToTextWithLinks = function ( html ) { var $html; if ( !cache.textWithLinks[ html ] ) { $html = this.wrapAndJquerify( html ); this.filterInvisible( $html ); this.appendWhitespaceToBlockElements( $html ); this.whitelistHtml( $html, 'a, span' ); cache.textWithLinks[ html ] = this.mergeWhitespace( $html.html() ); } return cache.textWithLinks[ html ]; }; /** * Generates HTML code for a link. * * @param {string} text Link text (plain text; will be sanitized) * @param {Object} props Link attributes (should at a minimum include href; will be sanitized) * @return {string} */ HUP.makeLinkText = function ( text, props ) { var key; for ( key in props ) { if ( !Object.prototype.hasOwnProperty.call( props, key ) ) { continue; } props[ key ] = this.htmlToText( props[ key ] ); } return this.jqueryToHtml( $( '' ).prop( props ).text( text ) ); }; module.exports = HtmlUtils; }() );