Have you heard about the DRY principle i.e. Don't Repeat Yourself. It looks like we are doing something very similar in each action with the only variation being the dialogStyle and nls. Can we instead have a method in the base class called showDialog which would be invoked something like this:

var dialog = this.showDialog(widget, { dialogStyle : "", nls : {} });

The implementation would mixin to default stuff i.e. title, dialogContent, onExecute this this.dialogArgs and the args it's passed in.

Would this work?