Using actionFunction and onclick to show a portion of the page

Question

I'm trying to use onclick and VF actionFunction to show a portion of a page.pageblocksection is not rendering.showdetail is false on vf page

I've set up an onclick like this:

<apex:commandLink value="Previous" 
                  action="{!setController.previous}"
                  onclick="hideDetail();"
                  rendered="{!setController.hasPrevious}"/>

<apex:actionFunction name="hideDetail"
                     action="{!hideDetail}"
                     rerender="detailBlock"/>

And I've set up a method like this in the controller:

//Called by actionFunction for Javascript onclick.
  public PageReference hideDetail() {
    showDetail = true;
    returnnull;
  }

And the detail pageBlock is like this:

<apex:pageBlockid="detailBlock">
<apex:pageBlockSection title="Position Detail"
                       collapsible="false"
                       rendered="{!showDetail}">

Answer 1

The commandLink needs to have a reRender attribute in order to call the actionFunction, otherwise it submits the form causing a postback. You can't cancel the postback, either, because that would also negate the effects on the controller. Worse, you're trying to submit the view state twice, so only one action would win in either case. Try the following modifications:

<apex:commandLink value="Previous" 
                  action="{!setController.previous}"
                  oncomplete="hideDetail();"
                  rendered="{!setController.hasPrevious}"
                  reRender="form"/> <!-- must have a reRender, at minimum -->
     <!-- also, we use "oncomplete" so that we don't have two conflicting view states -->

<apex:actionFunction name="hideDetail"
                     action="{!hideDetail}"
                     rerender="detailBlock"/>