How to detect button action in controller that is associated with overriden Visualforce page?

Question

I created a single Visualforce page that overrides default actions for almost all buttons for Event object. Actions are Edit, View, New Event, Accept and Decline. I need to detect the action in a controller which is associated with the Visualforce page.

Is there a way to do that? If yes, then how?

Answer 1

There's no way to discern whether the View action or the Edit action was used to visit your VF page. In both cases, the ApexPages.currentPage().getParameters() will contain just an 'id' attribute -- it will not be decorated with anything else.

The only solution is to create a separate redirect page for the Edit or View actions so that you can distinctly assign those pages as the overrides.

Your pages would have a page action similar to:

<apex:page standardController="MyObject__c" extensions="MyExtension" action="{!redirectToEdit}">

And the Apex would redirect:

public PageReference redirectToEdit(){
    PageReference ref = Page.MyObject;
    ref.getParameters().put('edit','true');
    return ref;
}

This question propose an alternative (using retUrl as your smell test for View vs. Edit, but I am suspect that it will work for all cases) How do I use the same Visualforce page to override view, new, and edit buttons on custom object