wrapWordSegmentWithElement | Parse the text out of a DOM element, and wrap a specific part of the text with a supplied wrapper element

wrapWordSegmentWithElement

/**
   * This wraps the extracted text segment with a parent wrapper element.
   * If the desired text segement is spread around few nodes, than it will wrap
   * EACH one of the nodes with the same parent wrapper.
   * As always, the startPosition is inclusive and the endPosition is exclusive
   * rootNode - must be a DOM element (not a jquery element)
   */
  function wrapWordSegmentWithElement(rootNode, startPosition, endPosition, emptyWrapperElement){
    var n, text='', walk=document.createTreeWalker(rootNode, NodeFilter.SHOW_TEXT, null, false);
    while (n = walk.nextNode()) {
      var nodeStartInclusive = text.length;
      var nodeEndExclusive = text.length+n.nodeValue.length;

      text += n.nodeValue; // nodeValue, when it's not a jquery element

      if (startPosition < nodeEndExclusive && endPosition > nodeStartInclusive){ // If we have an overlap

        var clonedWrapperElement = emptyWrapperElement.cloneNode(true);

        var currentNodeText = n.nodeValue;
        var part1Text = currentNodeText.substring(0, Math.max(0, startPosition - nodeStartInclusive ));
        var part2Text = currentNodeText.substring(Math.max(0, startPosition - nodeStartInclusive) , Math.min(currentNodeText.length, endPosition - nodeStartInclusive ));
        var part3Text = currentNodeText.substring(Math.min(currentNodeText.length, endPosition - nodeStartInclusive ) , currentNodeText.length);

        if (part3Text.length > 0) {
          var t = document.createTextNode(part3Text);
          $(t).insertAfter($(n));
        }

        if (part2Text.length > 0) {
          $(clonedWrapperElement).append(part2Text);
          $(clonedWrapperElement).insertAfter($(n));
        }

        if (part1Text.length > 0) {
          var t = document.createTextNode(part1Text);
          $(t).insertAfter($(n));
        }

        $(n).remove();
      }
    }
    return text;
  } // EOF wrapWordSegmentWithElement