Hi I have a lookup field which returns an opportunity if available, currently once i select an opportunity an actionsupport is triggered onchange, I then want to put that value from the lookup field into the controller using an apex:param however when i debug it in the controller its coming through as blank


<apex:inputField value="{!pb.CXT_Opportunity_Name__c}"> 
      <apex:actionSupport event="onchange" action="{!checkIfSelectedContactHasPendingOpp}"  rerender="testing">
          <apex:param name="PendingOpportunityName" assignTo="{!PendingOpportunityName}" value="{!pb.CXT_Opportunity_Name__c}"/>


public string PendingOpportunityName {get;set;}

 public pagereference checkIfSelectedContactHasPendingOpp(){

    return null;

enter image description here the debug just returns empty, any help would be awesome, Thanks

  • Is CXT_Opportunity_Name__c a Lookup?
    – Dan Jones
    Sep 28, 2016 at 16:54

2 Answers 2


If CXT_Opportunity_Name__c is a Lookup to another object, you're passing the object value to a String which wouldn't work.

What you'd need to do is assign the value to an instance of that object, then get the Name. For example:

Apex Class

public CXT_Pass_Registration__c PendingOpportunityName { // Change the variable to an instance of the object

public pagereference checkIfSelectedContactHasPendingOpp(){
    system.debug(PendingOpportunityName.Name); // Access the variable (object) and then, the Name
    return null;

public MyCustomController() {
    PendingOpportunityName = new CXT_Pass_Registration__c();

Visualforce Page

<apex:page controller="MyCustomController">
    <apex:inputField value="{!PendingOpportunityName.CXT_Opportunity_Name__c}" />
  • Hi, its a Lookup(Opportunity) however when i tried this i got the error : Invalid conversion from runtime type String to CXT_Pass_Registration__c Sep 28, 2016 at 19:35
  • @ClevelandDan See my updates.
    – Dan Jones
    Sep 29, 2016 at 9:47

You are missing rerender here. Add rerender in your actionsupport and also add in value in param

<apex:actionSupport event="onchange" action="{!checkIfSelectedContactHasPendingOpp}" rerender="none"> 
       <apex:param name="PendingOpportunityName" assignTo="{!PendingOpportunityName}" value="{!pb.CXT_Opportunity_Name__c}"/>    
  • I have added a rerender on the actionSupper which rerenders the outputpanel around the pageblock and added the value however its still null? Sep 28, 2016 at 16:05
  • <apex:actionSupport event="onchange" action="{!checkIfSelectedContactHasPendingOpp}" rerender="testing"> Sep 28, 2016 at 16:06
  • <apex:param name="PendingOpportunityName" assignTo="{!PendingOpportunityName}" value="{!pb.CXT_Opportunity_Name__c}"/> Sep 28, 2016 at 16:06
  • @ClevelandDan i is still not working for you?first check if there is required field and you didn't filled them then use immediate attribute. Sep 28, 2016 at 16:15
  • i added the immediate="true" still nothing, I have also tried adding a actionRegion to no avail Sep 28, 2016 at 16:22

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