Error: Unknown property 'OpportunityStandardController.opp'

Question

I have a controller extension and I get the unknown property error on page load.

public with sharing class ExtensionController{  
       public ApexPages.StandardController standardCon;    
       public ExtensionController(ApexPages.StandardController con){  
          standardCon = con;  
       }    
       public void populateRelAccFields(){  
          Opportunity opp = (Opportunity) standardCon.getRecord();  
          opp.Account = [select Phone, Type from Account where id =: opp.AccountId];  
       } 
    } 

Answer 1

By default, when using the getRecord() method, only the fields that are referenced in the associated Visualforce markup are available for querying on this SObject. All other fields, including fields from any related objects, must be queried using a SOQL expression. So without having your VF, lets just assume you need to do separate SOQL statements to ensure you have all the fields that you need.

You need to create a property in the extension

Public Opportunity opp      {get;set;}
Public Account acc          {get;set;}

public ExtensionController(ApexPages.StandardController con){
     standardCon = con;
     this.opp = (Opportunity) standardCon.getRecord();
     opp = [Select Id, Name, AccountId, Whatever Fields you want 
            From Opportunity 
            Where Id =: opp.id];
     acc = [Select Id, Name, Whatever fields you want 
            From Account
            Where Id =: opp.AccountId];

}

http://www.salesforce.com/us/developer/docs/pages/Content/apex_ApexPages_StandardController_getRecord.htm