I don't how to ask this, but assuming the user goes to "Accounting" > "Suppliers" > "Purchace Reciepts", now i need to do something only at that page.  How do i know that i am at that page?  Or i'm doing this the wrong way?

My code:

    instance.web.ViewManagerAction = instance.web.ViewManagerAction.extend({
        switch_mode: function(view_type, no_store, view_options){

            // for Testing, output to console the results that are similar to this

            console.log( "account.voucher" + "action='action_purchase_receipt'" );

            // some other code

            return  this._super(view_type, no_store, view_options);
        }
    });

Code from /addons/account_voucher:

       <menuitem
                id="menu_action_purchase_receipt"
                icon="STOCK_JUSTIFY_FILL"
                action="action_purchase_receipt"
                parent="account.menu_finance_payables"
                sequence="10"
                />