Render button based on condition

Question

I want to render/enable a command button based on a rollupsummary field value. If a rollupsummary field evalues to 0 enable it else keep it disabled.

Following is the code i am trying to achieve this functionality

public with sharing class test 
{ 
    public Account acc{get;set;}

    public test(){
       acc = [SELECT No_of_App__c   FROM Account];
    }
}

No able to render/enable diable the button

Answer 1

Your code should work properly. You are missing "" in rendered tag.

Try this code once

rendered="{!If(acc.No_Of_App__C = 0 ,True,False)}"

Answer 2

A couple of points, rendered is whether or not the component is visible, which is different from it appearing as a disabled button.

You can add an element to the page to help you debug

<apex:outputText>{!acc.no_of_app__c}</apex:outputText>

Also you shouldn't call your controller Test! See the tip at the bottom of this page http://www.salesforce.com/us/developer/docs/pages/Content/pages_controller_error_handling.htm