resources/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, copySelectors, removeSelectors, $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
  20                 // Show #wikiPreview if it's hidden to be able to scroll to it
  21                 // (if it is hidden, it's also empty, so nothing changes in the rendering)
  22                 $wikiPreview.show();
  23
  24                 // Jump to where the preview will appear
  25                 $wikiPreview[0].scrollIntoView();
  26
  27                 // List of selectors matching elements that we will
  28                 // update from from the ajax-loaded preview page.
  29                 copySelectors = [
  30                         // Main
  31                         '#wikiPreview',
  32                         '#wikiDiff',
  33                         '#catlinks',
  34                         '.hiddencats',
  35                         '#p-lang',
  36                         // Editing-related
  37                         '.templatesUsed',
  38                         '.mw-summary-preview'
  39                 ];
  40                 $copyElements = $( copySelectors.join( ',' ) );
  41
  42                 // Not shown during normal preview, to be removed if present
  43                 removeSelectors = [
  44                         '.mw-newarticletext'
  45                 ];
  46
  47                 $( removeSelectors.join( ',' ) ).remove();
  48
  49                 $spinner = $.createSpinner( {
  50                         size: 'large',
  51                         type: 'block'
  52                 });
  53                 $wikiPreview.before( $spinner );
  54                 $spinner.css( {
  55                         position: 'absolute',
  56                         marginTop: $spinner.height()
  57                 } );
  58                 // Make sure preview area is at least as tall as 2x the height of the spinner.
  59                 // 1x because if its smaller, it will spin behind the edit toolbar.
  60                 // (this happens on the first preview when editPreview is still empty)
  61                 // 2x because the spinner has 1x margin top breathing room.
  62                 $wikiPreview.css( 'minHeight', $spinner.height() * 2 );
  63
  64                 // Can't use fadeTo because it calls show(), and we might want to keep some elements hidden
  65                 // (e.g. empty #catlinks)
  66                 $copyElements.animate( {
  67                         opacity: 0.4
  68                 }, 'fast' );
  69
  70                 $previewDataHolder = $( '<div>' );
  71                 targetUrl = $( '#editform' ).attr( 'action' );
  72
  73                 // Gather all the data from the form
  74                 postData = $( '#editform' ).formToArray();
  75                 postData.push( {
  76                         name: e.target.name,
  77                         value: ''
  78                 } );
  79
  80                 // Load new preview data.
  81                 // TODO: This should use the action=parse API instead of loading the entire page
  82                 // Though that requires figuring out how to convert that raw data into proper HTML.
  83                 $previewDataHolder.load( targetUrl + ' ' + copySelectors.join( ',' ), postData, function () {
  84                         var i, $from;
  85                         // Copy the contents of the specified elements from the loaded page to the real page.
  86                         // Also copy their class attributes.
  87                         for ( i = 0; i < copySelectors.length; i++ ) {
  88                                 $from = $previewDataHolder.find( copySelectors[i] );
  89
  90                                 $( copySelectors[i] )
  91                                         .empty()
  92                                         .append( $from.contents() )
  93                                         .attr( 'class', $from.attr( 'class' ) );
  94                         }
  95
  96                         // Deprecated: Use mw.hook instead
  97                         $( mw ).trigger( 'LivePreviewDone', [copySelectors] );
  98
  99                         mw.hook( 'wikipage.content' ).fire( $wikiPreview );
 100
 101                         $spinner.remove();
 102                         $copyElements.animate( {
 103                                 opacity: 1
 104                         }, 'fast' );
 105                 } );
 106         }
 107
 108         $( function () {
 109                 // Do not enable on user .js/.css pages, as there's no sane way of "previewing"
 110                 // the scripts or styles without reloading the page.
 111                 if ( $( '#mw-userjsyoucanpreview' ).length || $( '#mw-usercssyoucanpreview' ).length ) {
 112                         return;
 113                 }
 114
 115                 // The following elements can change in a preview but are not output
 116                 // by the server when they're empty until the preview reponse.
 117                 // TODO: Make the server output these always (in a hidden state), so we don't
 118                 // have to fish and (hopefully) put them in the right place (since skins
 119                 // can change where they are output).
 120
 121                 if ( !document.getElementById( 'p-lang' ) && document.getElementById( 'p-tb' ) ) {
 122                         $( '#p-tb' ).after(
 123                                 $( '<div>' ).prop( 'id', 'p-lang' )
 124                         );
 125                 }
 126
 127                 if ( !$( '.mw-summary-preview' ).length ) {
 128                         $( '.editCheckboxes' ).before(
 129                                 $( '<div>' ).prop( 'className', 'mw-summary-preview' )
 130                         );
 131                 }
 132
 133                 if ( !document.getElementById( 'wikiDiff' ) && document.getElementById( 'wikiPreview' ) ) {
 134                         $( '#wikiPreview' ).after(
 135                                 $( '<div>' ).prop( 'id', 'wikiDiff')
 136                         );
 137                 }
 138
 139                 // Make sure diff styles are loaded
 140                 mw.loader.load( 'mediawiki.action.history.diff' );
 141
 142                 $( document.body ).on( 'click', '#wpPreview, #wpDiff', doLivePreview );
 143         } );
 144
 145 }( mediaWiki, jQuery ) );