Function mergeStreams

documentation/javascript/application.js:230–296

(stream1, stream2, value)

  }

  function mergeStreams(stream1, stream2, value) {
    var processed = 0;
    var result = '';
    var nodeStack = [];

    function selectStream() {
      if (stream1.length && stream2.length) {
        if (stream1[0].offset != stream2[0].offset)
          return (stream1[0].offset < stream2[0].offset) ? stream1 : stream2;
        else {
          /*
          To avoid starting the stream just before it should stop the order is
          ensured that stream1 always starts first and closes last:

          if (event1 == 'start' && event2 == 'start')
            return stream1;
          if (event1 == 'start' && event2 == 'stop')
            return stream2;
          if (event1 == 'stop' && event2 == 'start')
            return stream1;
          if (event1 == 'stop' && event2 == 'stop')
            return stream2;

          ... which is collapsed to:
          */
          return stream2[0].event == 'start' ? stream1 : stream2;
        }
      } else {
        return stream1.length ? stream1 : stream2;
      }
    }

    function open(node) {
      var result = '<' + node.nodeName.toLowerCase();
      for (var i = 0; i < node.attributes.length; i++) {
        var attribute = node.attributes[i];
        result += ' ' + attribute.nodeName.toLowerCase();
        if (attribute.value !== undefined && attribute.value !== false && attribute.value !== null) {
          result += '="' + escape(attribute.value) + '"';
        }
      }
      return result + '>';
    }

    while (stream1.length || stream2.length) {
      var current = selectStream().splice(0, 1)[0];
      result += escape(value.substr(processed, current.offset - processed));
      processed = current.offset;
      if ( current.event == 'start') {
        result += open(current.node);
        nodeStack.push(current.node);
      } else if (current.event == 'stop') {
        var node, i = nodeStack.length;
        do {
          i--;
          node = nodeStack[i];
          result += ('</' + node.nodeName.toLowerCase() + '>');
        } while (node != current.node);