Apex:ActionRegion blocking Controller function Action

Question

I'm trying to call a simple function in my Apex Controller and want to use an actionRegion to stop most sections of the page re-rendering. I note though when I add the actionRegion the controller function does not get called. I'm sure I've come across a similar issue years ago but can't find the exact same scenario detailed anywhere.

Basically here is a simple example. As you can see i've tried but commandButton and commandLink. I was trying to assign a parameter also but noted that the function is not even being called. It does call it if I don't use the actionRegion.

 <apex:actionRegion>
    <apex:commandButton rerender="testRerender" value="Select Instances" 
                        action="{!nullPageReference}" styleClass="slds-button">
        <apex:param name="editMode" value="EDIT" assignTo="{!viewMode}"/>
    </apex:commandButton>

    <apex:commandLink action="{!nullPageReference}" reRender="testRerender" value="SelectorS">
       <!--<apex:param name="editMode" value="EDIT" assignTo="{!viewMode}"/>-->
    </apex:commandLink>
 </apex:actionRegion>


public PageReference nullPageReference() {
    System.debug('HelloCalledFunc');
    return null;
}

Does anyone know why this does not work and if so how I can workaround it to call the function while in an actionRegion.

Thanks in advance.

Answer 1

If you are using <apex:actionRegion> to stop certain sections of the page to rerender, I'm afraid it does not support that.

According to the documenation,

Note that an <apex:actionRegion> component only defines which components the server processes during a request—it doesn’t define what areas of the page are re-rendered when the request completes. To control that behavior, use the rerender attribute on an <apex:actionSupport>, <apex:actionPoller>, <apex:commandButton>, <apex:commandLink>, <apex:tab>, or <apex:tabPanel> component.

So even if you find a workaround to make the <apex:actionFunction> under your <apex:actionRegion> to fire, you wont be able to stop sections from rerendering.

Try using the reRender attribute and rerender the specific sections that you want to.