TypeError：注入javascript时，undefined不是gwt中的函数

Question

When I try to inject this javascript code in my GWT project through ScriptInjector.fromString() it throws an error

TypeError: undefined is not a function Here is my code:

 (function(window) {
    var $canvas,
        onResize = function(event) {
          $canvas.attr({
            height: window.innerHeight,
            width: window.innerWidth
          });
        };

    $(document).ready(function() {
      $canvas = $('canvas');
      window.addEventListener('orientationchange', onResize, false);
      window.addEventListener('resize', onResize, false);
      onResize();

      $('form').signaturePad({
        drawOnly: true,
        defaultAction: 'drawIt',
        validateFields: false,
        lineWidth: 0,
        output: null,
        sigNav: null,
        name: null,
        typed: null,
        clear: 'input[type=reset]',
        typeIt: null,
        drawIt: null,
        typeItDesc: null,
        drawItDesc: null
      });
    });
  }(this));

The final javascript after injecting it in gwt own file which i found in inspect element was like below:

function com_google_gwt_core_client_ScriptInjector$FromString_ScriptInjector$FromString__Ljava_lang_String_2V(){
  this.com_google_gwt_core_client_ScriptInjector$FromString_scriptBody = "(function(window) {var $canvas,onResize = function(event) {}; $(document).ready(function() {  $canvas = $('canvas'); window.addEventListener('orientationchange', onResize, false);window.addEventListener('resize', onResize, false);onResize();  $('form').signaturePad({drawOnly: true, defaultAction: 'drawIt', validateFields: false,lineWidth: 0, output: null,sigNav: null,name: null,typed: null,clear: 'input[type=reset]',typeIt: null,drawIt: null,typeItDesc: null,drawItDesc: null})})}(this));";
 }

Any help will be highly appreciated. Thank you

Answer 1

I'd bet you're injecting your script in the wrong window and $ isn't defined there.

Most of the time, you want to inject script in the page you load your *.nocache.js script in, not the one (hidden iframe) GWT code actually runs, so don't forget to tell it to the ScriptInjector :

ScriptInjector.fromString(theScript)
              .setWindow(ScriptInjector.TOP_WINDOW)
              .inject();