20100430-hoge.js

var re = {
  'tumblr': /^http:\/\/[^.]+\.tumblr\.com\/post\//
};

function InlineImageInsert() {
  arguments.callee.prototype = {
    init: function(uri, api_uri, exp, line) {
      this.uri = uri;
      this.api_uri = api_uri;
      this.exp = exp;
      this.line = line;
      this.e();
    },

    e: function() {
      var self = this;
      var req = new XMLHttpRequest()
      req.open('get', self.api_uri, false);
      req.onreadystatechange = function() {
        if (req.readyState != 4) return;
        self.insertInlineImageNode(self.xpath(self.exp, req.responseXML), self.uri);
      };
      req.send(null);
    },

    insertInlineImageNode: function(image_uri, uri) {
      var line = this.line;
      var doc = line.ownerDocument;
      var inlineImageAnchorNode = doc.createElement('a');
      var inlineImageNode = doc.createElement('img');
      inlineImageNode.setAttribute('src', image_uri);
      inlineImageNode.setAttribute('class', 'inlineimage');
      inlineImageAnchorNode.setAttribute('href', uri);
      inlineImageAnchorNode.insertBefore(inlineImageNode, inlineImageAnchorNode.nextSibling);
      line.parentNode.insertBefore(doc.createElement('br'), line.nextSibling);
      line.parentNode.insertBefore(inlineImageAnchorNode, line.nextSibling);
    },

    xpath: function(exp, context) {
      var result = context.evaluate(exp, context, null, 2, null);
      return result.stringValue;
    }
  };
}

function processLine(e) {
  var iii = new InlineImageInsert();
  var line = e.target;
  if (line.getAttribute('class') != 'line text') return;
  var anchor = line.getElementsByClassName('url').item(0);
  if (!anchor) return;
  var uri = anchor.textContent;
  if (re.tumblr.test(uri)) {
    iii.init(uri, uri + '/xml', '//photo-url[@max-width="1280"]', e.target);
  }
}

document.addEventListener('DOMNodeInserted', processLine, true);