concept.js

var Wrapper, postToPastebin, wrapper;

// This is a concept for making a script wrapper with a userscript and pastebin.ca
Wrapper = function Wrapper(scriptId) {
  this.id = scriptId;
  return this;
};

// Will contain / contains the meta data
Wrapper.prototype.meta = null;

// Contains content waiting to be injected
Wrapper.prototype.queue = [];

// This functions grabs a copy of the meta.js
Wrapper.prototype.fetchMeta = function fetchMeta(callback) {
  GM_xmlhttpRequest({
    method: 'GET',
    url: "http://userscripts.org/scripts/source/" + this.id + ".meta.js",
    onload: (function(__this) {
      return (function onload() {
        return (function(xhr) {
          this.meta = xhr.responseText.trim();
          return callback(this.meta);
        }).apply(__this, arguments);
      });
    })(this)
  });
};

// Takes a comment, and adds it to the inject queue
Wrapper.prototype.queueComment = function queueComment(comment) {
  this.queue.push("// " + comment);
  return this;
};

// This function takes a key / value pair, converts it to a metadata string,
// then adds it to the inject queue
Wrapper.prototype.queueMetadata = function queueMetadata(key, value) {
  this.queue.push("// @" + key + "    " + value);
  return this;
};

// This function takes the pending changes, and applies it to the metadata
Wrapper.prototype.injectQueue = function injectQueue() {
  var end, temp;
  if ('string' !== typeof this.meta) {
    return false;
  }

  temp = this.meta.split("\n");
  end = temp.pop();

  Array.prototype.push.apply(temp, this.queue);
  this.queue = [];
  temp.push(end);

  this.meta = temp.join("\n");
  return this;
};

// This function takes the meta, and puts an closure around it
Wrapper.prototype.wrapWithFunction = function wrapWithFunction() {
  return "(function() {\n" + this.meta + "\n})();";
};

//### Helper functions
// This functions takes some code and a callback, sends it to pastebin.ca, then calls
// the callback when finished with the paste ID as the first and only argument
postToPastebin = function postToPastebin(code, callback) {
  return GM_xmlhttpRequest({
    url: 'http://pastebin.ca/quiet-paste.php?api=TQnk/tF+KeBcNWKL47BNh+d5Qywio6ko',
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    },
    data: "content=" + encodeURIComponent(code) + "&expiry=" +
           encodeURIComponent('5 minutes') + "&type=27",
    onload: function onload(xhr) {
      var result;
      result = xhr.responseText.split(':');
      return callback('SUCCESS' === result[0] ? result[1] : null);
    }
  });
};

//### Usage
wrapper = new Wrapper(12345);
wrapper.fetchMeta(function() {
  wrapper.queueComment('').
          queueComment('This wrapper can be used for installing updaters with scripts').
          queueMetadata('attribution', 'Marti').
          queueMetadata('attribution', 'Jesse Andrews').
          injectQueue();

  postToPastebin(wrapper.wrapWithFunction(), function(pasteId) {
    GM_openInTab("http://pastebin.ca/raw/" + pasteId + "#.meta.js");
  });
});