I have the following part in my visualforce page:

    <apex:actionFunction name="interestInShowConfirmed" action="{!interestInShowConfirmed}" />
    <apex:actionFunction name="registerInterest" action="{!openInterestedInShowPopUp}" >
        <apex:param name="chosenId" value=""/>

The way this code works, is that the "RegisterInterest" action function is called when a user clicks on a button (E.X. the button would execute: registerInterest('123213213'); ) - The register interest action function then generates a pop up to the user confirming their selection. Finally, when the user chooses the yes button on the pop up, the interestInShowConfirmed action function is called. I am running into a strange issue where I seemingly need to specify a re render target for these action functions or variable changes are not saved to the view state.

For example, this line of code

openPositionIdChosenForInterest = system.CurrentPageReference().getParameters().get('chosenId');

will return the correct passed Id if i specify a re render target for the "registerInterest" action function, but will return null if i do not. Also, if i specify a re render target only on "registerInterest" and not on "interestInShowConfirmed" - any global varriables set by the registerInterest action function will be null when "interestInShowConfirmed" tries to access them.

I'm guessing there is something I do not understand about re rendering and the view state - could someone fill me in?


Here is how the registerInterest function is called. It is a button inside a custom component included in the visualforce page:

<apex:commandButton value="{!cell['buttonLabel']}" onClick="{!cell['javascriptToCallOnClick']}('{!cell['argToStoreOnClick']}');" reRender="None" />

Also, if i don't include a rerender in this button, my action function is not called

1 Answer 1


Not specifying reRender causes a POST request, while using reRender uses the AJAX library to perform the request. If you don't use a reRender, you must use the assignTo attribute of apex:param, as the parameters won't be posted (i.e. currentPage().getParameters() won't have any values).

The documentation is not particularly clear on this, but basically you need to either use assignTo or reRender; if you use neither, your parameters will be useless. This is true for other supported elements, like apex:actionSupport, when using parameters. You must use either attribute to have proper parameter support.

  • It appears that even with a assignTo property it does not work: Ex. <apex:actionFunction name="registerInterest" action="{!openInterestedInShowPopUp}" > <apex:param name="chosenId" value="" assignTo="{!openPositionIdChosenForInterest}"/> </apex:actionFunction> and the code behind: if(openPositionIdChosenForInterest == null) { webpageUtilities.addError('Open Position Id not retrieved successfully from pop up', MAIN_PAGE_MESSAGES_ID); return; } will unforuntately always trigger the message that the Id is null Mar 13, 2019 at 5:18
  • @HansDonkersloot Hmm... I don't think I have enough context then. Maybe you could add more code in your question for context?
    – sfdcfox
    Mar 13, 2019 at 5:24
  • Admittedly this is a really complex page, which is likely why there is an issue somewhere here - I added the code for how the action function is invoked, hopefully that might explain some things Mar 13, 2019 at 5:47
  • The documentation is not particularly clear on this - so true
    – cropredy
    Mar 13, 2019 at 17:11

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