Extjs 5. Ext.application is not a function. Why?

Question

I get an error in console: Ext.application is not a function. My index.html file contains this code:

...
<link rel="stylesheet" type="text/css" href="/ext-5.0.1/packages/ext-theme-neptune/build/resources/ext-theme-neptune-all.css" />
<script src="/ext-5.0.1/ext-all-debug.js"></script>    
<script type="text/javascript" src="app.js"></script>    
...

While app.js has just this code, taken from one demo:

Ext.application({
name: 'AM',
appFolder: 'app',
launch: function() {
    Ext.create('Ext.container.Viewport', {
        layout: 'fit',
        items: [{
                xtype: 'panel',
                title: 'Users',
                html : 'List of users will go here'
        }]
    });
}
});

EDIT

By the way, even running "official" /ext-5.0.1/examples/app/simple/simple.html I get the same error. Why is that?

Answer 1

Wrap the call to Ext.application inside an Ext.onReady block.

// app.js
Ext.onReady(function() {
  Ext.application({
    name: 'AM',
    appFolder: 'app',
    launch: function() {
      Ext.create('Ext.container.Viewport', {
        layout: 'fit',
        items: [{
          xtype: 'panel',
          title: 'Users',
          html : 'List of users will go here'
        }]
      });
    }
  });
})

The reason this is necessary, BTW, is that the ext-all-debug.js files doesn't contain all of ExtJS. It contains the bootstrap code - the code that knows how to get everything else. Part of that "everything else" is the application code. So until that's had a chance to run, Ext.application doesn't exist.

The portal example you mention works because it uses the result of a sencha app build - the microloader.js. This loads up a full version of ExtJS (or rather, the parts used in the app), and thus Ext.application is already defined by the time it's used. (The same goes with Sencha Fiddle - you wouldn't need the Ext.onReady there either)

Answer 2

Instead of

<script src="/ext-5.0.1/ext-all-debug.js"></script>

You should use

<script src="/ext-5.0.1/build/ext-all-debug.js"></script>

The second one contains all Components and Classes as expected.