alpaca/dist/lib/typeahead.js/src/typeahead/highlight.js

Alpaca provides the easiest and fastest way to generate interactive forms for the web and mobile devices. It runs simply as HTML5 or more elaborately using Bootstrap, jQuery Mobile or jQuery UI. Alpaca uses Handlebars to process JSON schema and provide

/*
 * typeahead.js
 * https://github.com/twitter/typeahead.js
 * Copyright 2013-2014 Twitter, Inc. and other contributors; Licensed MIT
 */

// inspired by https://github.com/jharding/bearhug

var highlight = (function(doc) {
  'use strict';

  var defaults = {
        node: null,
        pattern: null,
        tagName: 'strong',
        className: null,
        wordsOnly: false,
        caseSensitive: false
      };

  return function hightlight(o) {
    var regex;

    o = _.mixin({}, defaults, o);

    if (!o.node || !o.pattern) {
      // fail silently
      return;
    }

    // support wrapping multiple patterns
    o.pattern = _.isArray(o.pattern) ? o.pattern : [o.pattern];

    regex = getRegex(o.pattern, o.caseSensitive, o.wordsOnly);
    traverse(o.node, hightlightTextNode);

    function hightlightTextNode(textNode) {
      var match, patternNode, wrapperNode;

      if (match = regex.exec(textNode.data)) {
        wrapperNode = doc.createElement(o.tagName);
        o.className && (wrapperNode.className = o.className);

        patternNode = textNode.splitText(match.index);
        patternNode.splitText(match[0].length);
        wrapperNode.appendChild(patternNode.cloneNode(true));

        textNode.parentNode.replaceChild(wrapperNode, patternNode);
      }

      return !!match;
    }

    function traverse(el, hightlightTextNode) {
      var childNode, TEXT_NODE_TYPE = 3;

      for (var i = 0; i < el.childNodes.length; i++) {
        childNode = el.childNodes[i];

        if (childNode.nodeType === TEXT_NODE_TYPE) {
          i += hightlightTextNode(childNode) ? 1 : 0;
        }

        else {
          traverse(childNode, hightlightTextNode);
        }
      }
    }
  };

  function getRegex(patterns, caseSensitive, wordsOnly) {
    var escapedPatterns = [], regexStr;

    for (var i = 0, len = patterns.length; i < len; i++) {
      escapedPatterns.push(_.escapeRegExChars(patterns[i]));
    }

    regexStr = wordsOnly ?
      '\\b(' + escapedPatterns.join('|') + ')\\b' :
      '(' + escapedPatterns.join('|') + ')';

    return caseSensitive ? new RegExp(regexStr) : new RegExp(regexStr, 'i');
  }
})(window.document);