AJAX wrapper to jQuery's AJAX API to achieve a more scientific response handle framework

ajax.js

// @require `underscore` or `lodash`

// Figure out type of `obj'
var typeid = function (obj) {
  return Object.prototype.toString.call(obj).match(/\s([a-zA-Z]+)/)[1].toLowerCase();
};

var ajax = function (method, url, data, options, handler) {
  if (typeid(options == 'function')) {
    handler = options; options = {};
  }

  _(options).extend({
    method: method,
    url: url,
    data: data,
    complete: function (xhr, statusText) {
      if (typeid(handler) == 'function') {
        return handler(xhr.responseJSON || xhr.responseXML || xhr.responseText, xhr.status, xhr);
      }
    }
  });

  return $.ajax(options);
};

_(ajax).extend({

  ///
  // ajax.handler([Object]);
  // ajax.handler([Array]);
  // ajax.handler([String status | Array], [Function handler | Array]);
  // ajax.handler([Function matcher], [Function handler | Array]);
  ///
  handler: function (matcher, handler, _collection) {
    if (!handler) {
      handler = matcher;
      if (typeid(handler) == 'object') {
        handler = _.map(handler,  function (handler, matcher, _collection) {
          return ajax.handler(matcher, handler, _collection);
        });
      }
      if (typeid(handler) == 'array') {
        return function (data, status, xhr) {
          _.each(handler, function (handler) { handler(data, status, xhr); });
        };
      }
    } else {
      if (matcher == '*') {
        matcher = function () { return true; };
      }
      if (matcher == '___') {
        matcher = function (data, status, xhr) {
          return !~Object.keys(_collection).indexOf('' + status);
        };
      }
      if (typeid(matcher) == 'string') {
        matcher = [ matcher ];
      }
      if (typeid(matcher) == 'array') {
        matcher = function (matcher) {
          return function (data, status, xhr) {
            return !!~matcher.indexOf('' + status);
          };
        }(matcher);
      }
      if (typeid(handler) == 'array') {
        handler = function (handler) {
          return function (data, status, xhr) {
            _.each(handler, function (handler) { handler(data, status, xhr); });
          };
        }(handler);
      }
      if (typeid(matcher) == 'function') {
        return function (data, status, xhr) {
          return matcher(data, status, xhr) && handler(data, status, xhr);
        };
      }
    }
  }

});

_.each(['post', 'get'], function (method) {
  ajax[method] = ajax.bind(null, method);
});