viewModel link load callback or event help

I am dynamically creating a form like this, with also passing in a new model as part of the links config:

Code:

this.createTab(record, {
    xtype: 'editform',
    viewModel: {
        links: {
            additionalData: {
                reference: 'MyApp.model.AdditionalData',
                id: record.getId()
            }
        },
        data: {
            entry: record
        }
    }
});

However the form is rendered before the AdditionalData model is loaded, and I don't know what to trigger some event that tells my form or controller this model has been loaded...This wouldn't be an issue if I 2-way binded my form, but the form is just 1 big html text editor, and 2 way binding this large field is wonky, like the cursor moves all over the place and sluggish. This is fine, so I want to set the field manually. What can I do to populate this form field upon the model being loaded from the server?



viewModel link load callback or event help