toru.js

/**
 * toru.js
 * Kosei Moriyama <cou929@gmail.com>
 * 
 * Get selection area, traverse the area, obtain xpath of dom elements inside the area
 * and send the xpath to torerundesu server.
 * 
 * TODO:
 * - Find cookies and check the user is logined or not.
 * - Send results to the server.
 * - Show selected area.
 * - Build add-ons (future).
 */

javascript:(function(){
/*
 * Make XPath from node
 * http://ido.nu/kuma/2007/10/25/tiny-xpath-related-utilities-in-firebug/
 */
function xN(xpath, context) {
    var snapshot = document.evaluate(xpath, context, null,
        XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    return snapshot.snapshotLength;
}
function nodePath(node) {
    return ( node != document ? (
        [nodePath(node.parentNode) , node.nodeName ].join('/') +
        "[" + (xN('./preceding-sibling::' + node.nodeName, node) + 1) + "]"
    ) : '');
}

/*
 * Remove empty node
 * https://developer.mozilla.org/en/Whitespace_in_the_DOM
 */
function is_all_ws( nod ) {
  return !(/[^\t\n\r ]/.test(nod.data));
}

function is_ignorable( nod ) {
  return ( nod.nodeType == 8) || // comment node
  ( (nod.nodeType == 3) && is_all_ws(nod) ); // text node && all white space
}

/**
 * Get xpath from selection area
 * @param  selection   The selection object
 * @return             An array which contains set of XPath
 *                     which is leaf of dom tree contained by the selection.
 */
function getXPath(selection) {
  var range = selection.getRangeAt(0);
  var root = range.commonAncestorContainer;
  var inside_nodes = [];
  var xpath = [];

  trv(root);

  for (var i=0, node; node=inside_nodes[i]; i++) {
    var cur = node;
    while (cur.nodeType === 3)
      cur = node.parentNode;
    xpath.push(nodePath(cur));
  }

  return xpath;

  /**
   * Traverse dom tree by dfs, and find selected nodes.
   * 
   * @param node  The node which is currently searched.
   * @return      Nothing is returned.
   *              The function stores results into 'inside_nodes'
   */
  function trv(node) {
    if (is_ignorable(node)) && return;

    if (selection.containsNode(node, false))
      inside_nodes.push(node);
    else
      for (var i=0, n; n=node.childNodes[i]; i++)
        trv(n);
  }
}

/*
 * Application code
 */
var selection = window.getSelection();

if (!selection.isCollapsed) {
  var xpath = getXPath(selection);

  alert(xpath);
}
})();