While creating an ExtJS form with several radio buttons today I ran into a bug which caused none of them to work as expected, even though there were no errors/exceptions. To cut a long story short, it was because I was setting the name to "schedule[include_type]" - like this:

{
  xtype: 'radio',
  name: 'schedule[include_type]',
  inputValue: 'page',
  boxLabel: 'Show page:'
}

This radio button is one of 4, which allows the user which type of file they want to include on a particular model (a Schedule in this case) - be it Page, Video, Category or one other. The thing is - none of them work with the square brackets in the name. If you remove the brackets, they all work correctly, but the server-side is relying on those brackets to be present to group the data correctly.

In the end I bit the bullet and updated my submit method to add a new parameter directly - here's a full example:

form = new Ext.form.FormPanel({
  items: [
    {
      xtype: 'radio',
      name: 'include_type',
      inputValue: 'page',
      boxLabel: 'Show page:'
    },
    {
      xtype: 'radio',
      name: 'include_type',
      inputValue: 'category',
      boxLabel: 'Show category:'
    },
    ... plus some extra items
  ],
  buttons: [
    {
      text: 'Save',
      handler: function() {
        
        //find the currently selected include_type from the form
        var include_type = this.form.getValues()['include_type'];
        
        //note the params option - this needs to be added manually otherwhise 
        //schedule[include_type] won't appear
        form.form.submit({
          waitMsg: 'Saving Data...',
          params: "schedule[include_type]=" + include_type,
          url: some url...
        });
      }
    }
  ]
})