how to drop a gadget?

gistfile1.txt

/*jslint indent: 2, maxlen: 80, nomen: true */
/*global console, window, document, rJS, RSVP, $ */
(function (window, document, rJS) {
  "use strict";

  rJS(window)

    /**
     * Override navigation of jQuery Mobile and allow deeplinking. Missing
     * pages will now be loaded and added to the DOM as new gadgets - and
     * removed again once the user leaves them.
     *
     * @method  render
     * @param   {Object}  gadget  Gadget object
     */
    .declareMethod('render', function () {
      var gadget = this;

      // override
      $(document)
        .on('pagebeforechange', function (e, data) {
          var target, clean_url, parsed_url, is_enhanced;

          if (e && data) {
            if (typeof data.toPage === "string") {
              target = data.toPage.split("#")[1];

            // overwrite JQM history
            } else if ($.mobile.navigate.history.initialDst &&
                  window.location.hash !== "") {

              // this is the inital page (not) loaded
              // this page needs to be stored as initial page in JQM
              clean_url = window.location.href.split("#")[0];
              parsed_url = $.mobile.path.parseUrl(clean_url);
              target = $.mobile.navigate.history.initialDst;

              // remove initialDist, otherwise closing popups
              // will trigger double backward transition.
              delete $.mobile.navigate.history.initialDst;

              // Correctly set index as first page in JQM history
              $.mobile.navigate.history.stack[0].hash = "";
              $.mobile.navigate.history.stack[0].url = clean_url;
              $.mobile.path.documentUrl = parsed_url;
              $.mobile.path.documentBase = parsed_url;
            }
          }

          // load "missing pages" into DOM and re-trigger transition
          if (target && !document.getElementById(target)) {
            return gadget.declareGadget(
              "./" + target + ".html",
              {"element": gadget.__element, "scope": target}
            )
            .then(function (new_gadget) {
              if (new_gadget.render) {
                new_gadget.render();
              }
              $.mobile.changePage("#" + target);
              document.getElementById(target)
                .setAttribute("data-external-page", true);

              // translate
              return gadget.acquire_translateAll($(new_gadget.__element));
            })
            .fail(console.log);
          }
        })
        .on('pagehide', 'div.ui-page', function () {
          var page, id, is_enhanced;

          page = this;
          id = this.id;
          is_enhanced = $(page).data("mobilePage");

          if (page.getAttribute('data-external-page')) {
            if (is_enhanced) {
              $(this).page('destroy').remove();
            }
            return gadget.dropGadget(id).fail(console.log);
          }
        });
    })

    /* ======================== METHODS TO EXPOSE ========================= */

    /* ========================= METHODS NEEDED =========================== */
    .declareAcquiredMethod("acquire_translateAll", "acquire_translateAll");

}(window, document, rJS));