Shopware postMessage enabled iFrame in a tab

postmessage-iframe-tab.js

//{namespace name=backend/order/main}
//{block name="backend/order/view/detail/window"}
//{$smarty.block.parent}
Ext.define('Shopware.apps.Order.view.detail.Window-MyIframePostMessageApi', {
    override: 'Shopware.apps.Order.view.detail.Window',

    createTabPanel: function() {
        var me = this, tabs;
	tabs = me.callParent(arguments);
        tabs.add(me.createTabWithIFrame());

	return tabs;
    },

    createTabWithIFrame: function () {
        var me = this;

        return me.createPostMessageApiEnabledTabComponent(
            'Mein Tab',
            '{url controller=MyController action=index orderId=""}' + me.record.get('id')
        );
    },

    createPostMessageApiEnabledTabComponent: function(label, url) {
        var me = this,
            swModuleManager = Shopware.ModuleManager,
            // @see Shopware.ModuleManager.createSimplifiedModule()
            instance = swModuleManager.uuidGenerator.generate(),
            content = swModuleManager.createContentFrame(url, instance, true),
            subApp = null,
            windows = Ext.create('Ext.util.MixedCollection'),
            contentWindow;

        contentWindow = Ext.create('Ext.Component', {
            title: label,
            component: 'main',
            content: 'content',
            style: 'height: 100%',
            listeners: {
                render: function(component, eOpts) {
                    component.el.appendChild(content);
                    component.setLoading(true);
                },
            },
        });

        content.dom._window = contentWindow;
        windows.add('main', contentWindow);

        // push component into registry
        swModuleManager.modules.add(instance, {
            name: url,
            instance: instance,
            subApp: subApp,
            windows: windows
        });

        return contentWindow;
    }
});
//{/block}