Ext.application and Ext.override in launch function does not work?

[arcan9ne]

I'm moving towards the ExtJS 4.0 MVC architecture and I had an override in my old init method which worked:

Old code that worked:

APP.app = function() {
...
  return {
    init: function() {
      Ext.QuickTips.init();
      
      Ext.override(Ext.Ajax.request, {
        extraParams: {
          param_1: Ext.get('my_id').getValue(),
          param_2: Ext.get('my_id_2').getValue(),
          param_3: Ext.get('my_id_3').getValue()
        }
      });
    }
  }
}

Ext.onReady(APP.app.init, APP.app);

New code that doesn't

Ext.application({
  name: 'APP',
  autoCreateViewport: true,
  launch: function() {
    Ext.override(Ext.Ajax.request, {
      extraParams: {
        param_1: Ext.get('my_id').getValue(),
        param_2: Ext.get('my_id_2').getValue(),
        param_3: Ext.get('my_id_3').getValue()
      }
    });
  }
});

As you can see, I've moved this override to the launch function. You will also realize that I am retrieving my values from elements in the page after it has been loaded which is the reason for applying the override in the launch function.

Any help would be much appreciated.

[arcan9ne]

My other thought would be to add a listener for when the page is loaded, but I don't see any events specific Ext.app.application. Are there any?

[remeis]

Hi,

basically, I've the same problem: I'd like to override Ext.data.proxy.Server such that it will react on a failed request:

Ext.data.proxy.Server.override({
  constructor: function() {
    console.log('overriden data.proxy.Server constructed');
    return this.callOverridden(arguments);
  },

  afterRequest: function(request, success) {
    if (! request.operation.success) {
      console.log('request failed');
    }
  }
});

This works if I put this code directly above the store definition in the corresponding store file (app/store/myStore.js). Because I'd like to apply this to every store (in app/store) it would make sense to override the class in the main application file (app.js). But above the application definition doesn't work:

<-put the code above here does not work->

Ext.application({
  name: 'myApp',
  appFolder: 'app',
  ...
)};

I will continue working on this problem.

[remeis]

I got it working: I've moved the above code with the Ext.override directive to the launch function of the application, like you did:

Ext.application({
  ...
  launch: function() {
    Ext.data.proxy.Server.override({
      ...
    });
    ...
  }
});

First, it did not work either. Then I switched the ExtJS library from ext.js to ext-debug.js in the HTML header:

<script src="extjs/ext-debug.js" type="text/javascript"></script>

And it magically worked!

So I guess, in order to use ext.js again (for the final apllication version), there is something missing, maybe one has to require a specific class, which I'm not aware of?

[arcan9ne]

Thanks a lot remeis, that worked for me as well! I will do some further testing and if I figure out what is missing then will post the solution using ext-all.js.

[skirtle]

I think the most widely used technique for applying overrides in ExtJS 4 is:

Ext.require('classname', function() {
    // Callback for when the class has been loaded. Apply the overrides here.
});

This would be placed before the call to Ext.application().

I'm a bit confused by the use of Ext.override() to set extraParams on Ext.Ajax.request. I don't really understand how that ever worked. As far as I can tell it'll be setting the extraParams on the prototype of the request function. Unless you're doing something really odd like new Ext.Ajax.request({...}) I can't see why they'd get picked up. Wouldn't this be a little more straightforward?

Ext.apply(Ext.Ajax.extraParams, {
    param_1: Ext.get('my_id').getValue(),
    param_2: Ext.get('my_id_2').getValue(),
    param_3: Ext.get('my_id_3').getValue()
});

I also wonder whether you'd be better off using a cookie instead.

[remeis]

I think the most widely used technique for applying overrides in ExtJS 4 is:

Ext.require('classname', function() {
    // Callback for when the class has been loaded. Apply the overrides here.
});

Thanks skirtle! This code looks much more elegant and also works for me using ext.js.