resources/src/mediawiki.action/mediawiki.action.edit.preview.js

   1 /**
   2  * Live edit preview.
   3  */
   4 ( function ( mw, $ ) {
   5
   6         /**
   7          * @param {jQuery.Event} e
   8          */
   9         function doLivePreview( e ) {
  10                 var $wikiPreview, $editform, copySelectors, $copyElements, $spinner,
  11                         targetUrl, postData, $previewDataHolder;
  12
  13                 e.preventDefault();
  14
  15                 // Deprecated: Use mw.hook instead
  16                 $( mw ).trigger( 'LivePreviewPrepare' );
  17
  18                 $wikiPreview = $( '#wikiPreview' );
  19                 $editform = $( '#editform' );
  20
  21                 // Show #wikiPreview if it's hidden to be able to scroll to it
  22                 // (if it is hidden, it's also empty, so nothing changes in the rendering)
  23                 $wikiPreview.show();
  24
  25                 // Jump to where the preview will appear
  26                 $wikiPreview[0].scrollIntoView();
  27
  28                 // List of selectors matching elements that we will
  29                 // update from from the ajax-loaded preview page.
  30                 copySelectors = [
  31                         // Main
  32                         '#firstHeading',
  33                         '#wikiPreview',
  34                         '#wikiDiff',
  35                         '#catlinks',
  36                         '.hiddencats',
  37                         '#p-lang',
  38                         // Editing-related
  39                         '.templatesUsed',
  40                         '.limitreport',
  41                         '.mw-summary-preview'
  42                 ];
  43                 $copyElements = $( copySelectors.join( ',' ) );
  44
  45                 // Not shown during normal preview, to be removed if present
  46                 $( '.mw-newarticletext' ).remove();
  47
  48                 $spinner = $.createSpinner( {
  49                         size: 'large',
  50                         type: 'block'
  51                 } );
  52                 $wikiPreview.before( $spinner );
  53                 $spinner.css( {
  54                         marginTop: $spinner.height()
  55                 } );
  56
  57                 // Can't use fadeTo because it calls show(), and we might want to keep some elements hidden
  58                 // (e.g. empty #catlinks)
  59                 $copyElements.animate( { opacity: 0.4 }, 'fast' );
  60
  61                 $previewDataHolder = $( '<div>' );
  62                 targetUrl = $editform.attr( 'action' );
  63                 targetUrl += targetUrl.indexOf( '?' ) !== -1 ? '&' : '?';
  64                 targetUrl += $.param( {
  65                         debug: mw.config.get( 'debug' ),
  66                         uselang: mw.config.get( 'wgUserLanguage' ),
  67                         useskin: mw.config.get( 'skin' )
  68                 } );
  69
  70                 // Gather all the data from the form
  71                 postData = $editform.formToArray();
  72                 postData.push( {
  73                         name: e.target.name,
  74                         value: ''
  75                 } );
  76
  77                 // Load new preview data.
  78                 // TODO: This should use the action=parse API instead of loading the entire page,
  79                 // although that requires figuring out how to convert that raw data into proper HTML.
  80                 $previewDataHolder.load( targetUrl + ' ' + copySelectors.join( ',' ), postData, function () {
  81                         var i, $from, $next, $parent;
  82
  83                         // Copy the contents of the specified elements from the loaded page to the real page.
  84                         // Also copy their class attributes.
  85                         for ( i = 0; i < copySelectors.length; i++ ) {
  86                                 $from = $previewDataHolder.find( copySelectors[i] );
  87
  88                                 if ( copySelectors[i] === '#wikiPreview' ) {
  89                                         $next = $wikiPreview.next();
  90                                         // If there is no next node, use parent instead.
  91                                         // Only query parent if needed, false otherwise.
  92                                         $parent = !$next.length && $wikiPreview.parent();
  93
  94                                         $wikiPreview
  95                                                 .detach()
  96                                                 .empty()
  97                                                 .append( $from.contents() )
  98                                                 .attr( 'class', $from.attr( 'class' ) );
  99
 100                                         mw.hook( 'wikipage.content' ).fire( $wikiPreview );
 101
 102                                         // Reattach
 103                                         if ( $parent ) {
 104                                                 $parent.append( $wikiPreview );
 105                                         } else {
 106                                                 $next.before( $wikiPreview );
 107                                         }
 108
 109                                 } else {
 110                                         $( copySelectors[i] )
 111                                                 .empty()
 112                                                 .append( $from.contents() )
 113                                                 .attr( 'class', $from.attr( 'class' ) );
 114                                 }
 115                         }
 116
 117                         // Deprecated: Use mw.hook instead
 118                         $( mw ).trigger( 'LivePreviewDone', [copySelectors] );
 119
 120                         $spinner.remove();
 121                         $copyElements.animate( {
 122                                 opacity: 1
 123                         }, 'fast' );
 124                 } );
 125         }
 126
 127         $( function () {
 128                 // Do not enable on user .js/.css pages, as there's no sane way of "previewing"
 129                 // the scripts or styles without reloading the page.
 130                 if ( $( '#mw-userjsyoucanpreview' ).length || $( '#mw-usercssyoucanpreview' ).length ) {
 131                         return;
 132                 }
 133
 134                 // The following elements can change in a preview but are not output
 135                 // by the server when they're empty until the preview response.
 136                 // TODO: Make the server output these always (in a hidden state), so we don't
 137                 // have to fish and (hopefully) put them in the right place (since skins
 138                 // can change where they are output).
 139
 140                 if ( !document.getElementById( 'p-lang' ) && document.getElementById( 'p-tb' ) ) {
 141                         $( '#p-tb' ).after(
 142                                 $( '<div>' ).attr( 'id', 'p-lang' )
 143                         );
 144                 }
 145
 146                 if ( !$( '.mw-summary-preview' ).length ) {
 147                         $( '.editCheckboxes' ).before(
 148                                 $( '<div>' ).addClass( 'mw-summary-preview' )
 149                         );
 150                 }
 151
 152                 if ( !document.getElementById( 'wikiDiff' ) && document.getElementById( 'wikiPreview' ) ) {
 153                         $( '#wikiPreview' ).after(
 154                                 $( '<div>' ).attr( 'id', 'wikiDiff' )
 155                         );
 156                 }
 157
 158                 // This should be moved down to '#editform', but is kept on the body for now
 159                 // because the LiquidThreads extension is re-using this module with only half
 160                 // the EditPage (doesn't include #editform presumably, bug 55463).
 161                 $( document.body ).on( 'click', '#wpPreview, #wpDiff', doLivePreview );
 162         } );
 163
 164 }( mediaWiki, jQuery ) );