resources/src/jquery/jquery.highlightText.js

   1 /**
   2  * Plugin that highlights matched word partials in a given element.
   3  * TODO: Add a function for restoring the previous text.
   4  * TODO: Accept mappings for converting shortcuts like WP: to Wikipedia:.
   5  */
   6 ( function () {
   7
   8         $.highlightText = {
   9
  10                 // Split our pattern string at spaces and run our highlight function on the results
  11                 splitAndHighlight: function ( node, text ) {
  12                         var i,
  13                                 words = text.split( ' ' );
  14                         for ( i = 0; i < words.length; i++ ) {
  15                                 if ( words[ i ].length === 0 ) {
  16                                         continue;
  17                                 }
  18                                 $.highlightText.innerHighlight(
  19                                         node,
  20                                         new RegExp( '(^|\\s)' + mw.RegExp.escape( words[ i ] ), 'i' )
  21                                 );
  22                         }
  23                         return node;
  24                 },
  25
  26                 prefixHighlight: function ( node, prefix ) {
  27                         $.highlightText.innerHighlight(
  28                                 node,
  29                                 new RegExp( '(^)' + mw.RegExp.escape( prefix ), 'i' )
  30                         );
  31                 },
  32
  33                 // scans a node looking for the pattern and wraps a span around each match
  34                 innerHighlight: function ( node, pat ) {
  35                         var i, match, pos, spannode, middlebit, middleclone;
  36                         if ( node.nodeType === Node.TEXT_NODE ) {
  37                                 // TODO - need to be smarter about the character matching here.
  38                                 // non latin characters can make regex think a new word has begun: do not use \b
  39                                 // http://stackoverflow.com/questions/3787072/regex-wordwrap-with-utf8-characters-in-js
  40                                 // look for an occurrence of our pattern and store the starting position
  41                                 match = node.data.match( pat );
  42                                 if ( match ) {
  43                                         pos = match.index + match[ 1 ].length; // include length of any matched spaces
  44                                         // create the span wrapper for the matched text
  45                                         spannode = document.createElement( 'span' );
  46                                         spannode.className = 'highlight';
  47                                         // shave off the characters preceding the matched text
  48                                         middlebit = node.splitText( pos );
  49                                         // shave off any unmatched text off the end
  50                                         middlebit.splitText( match[ 0 ].length - match[ 1 ].length );
  51                                         // clone for appending to our span
  52                                         middleclone = middlebit.cloneNode( true );
  53                                         // append the matched text node to the span
  54                                         spannode.appendChild( middleclone );
  55                                         // replace the matched node, with our span-wrapped clone of the matched node
  56                                         middlebit.parentNode.replaceChild( spannode, middlebit );
  57                                 }
  58                         } else if (
  59                                 node.nodeType === Node.ELEMENT_NODE &&
  60                                 // element with childnodes, and not a script, style or an element we created
  61                                 node.childNodes &&
  62                                 !/(script|style)/i.test( node.tagName ) &&
  63                                 !(
  64                                         node.tagName.toLowerCase() === 'span' &&
  65                                         node.className.match( /\bhighlight/ )
  66                                 )
  67                         ) {
  68                                 for ( i = 0; i < node.childNodes.length; ++i ) {
  69                                         // call the highlight function for each child node
  70                                         $.highlightText.innerHighlight( node.childNodes[ i ], pat );
  71                                 }
  72                         }
  73                 }
  74         };
  75
  76         /**
  77          * Highlight certain text in current nodes (by wrapping it in `<span class="highlight">...</span>`).
  78          *
  79          * @param {string} matchString String to match
  80          * @param {Object} [options]
  81          * @param {string} [options.method='splitAndHighlight'] Method of matching to use, one of:
  82          *   - 'splitAndHighlight': Split `matchString` on spaces, then match each word separately.
  83          *   - 'prefixHighlight': Match `matchString` at the beginning of text only.
  84          * @return {jQuery}
  85          * @chainable
  86          */
  87         $.fn.highlightText = function ( matchString, options ) {
  88                 options = options || {};
  89                 options.method = options.method || 'splitAndHighlight';
  90                 return this.each( function () {
  91                         var $el = $( this );
  92                         $el.data( 'highlightText', { originalText: $el.text() } );
  93                         $.highlightText[ options.method ]( this, matchString );
  94                 } );
  95         };
  96
  97 }() );