actionsupport + rerender + pageblocktable = problem

Question

Context

I want to show a pageblocktable with two input columns, Activity Type and Work Country, both populated with custom picklists as shown in the visualforce code below.

Each row represents a Period object, and has its own instance of a PeriodController. For each row, I want the second picklist Work Country to be dependent on the value selected in the first, based on logic that I want to define in apex.

Code

page:

<apex:form id="theForm">
    <apex:pageBlockTable value="{!c.periodControllers}" var="periodController" rendered="{!c.periodControllers.size>0}">
        <apex:column >
            <apex:selectList value="{!periodController.period.Activity_Type__c}" size="1" id="work_type" required="true" >
                <apex:selectOptions value="{!periodController.soActivities}"/>
                <apex:actionSupport event="onchange" action="{!periodController.updateDynamicPicklists}" rerender="work_country"/>
            </apex:selectList>
        </apex:column >
        <apex:column >
            <apex:outputPanel id="work_country">
                <apex:selectList value="{!periodController.period.Work_Country__c}" size="1" disabled="{!periodController.soWorkCountries.size==0}">
                    <apex:selectOptions value="{!periodController.soWorkCountries}"/>
                </apex:selectList>
            </apex:outputPanel>
        </apex:column>
    </apex:pageBlockTable>
</apex:form>

PeriodController:

public PageReference updateDynamicPicklists() {
    System.debug( this.period.Activity_Type__c );
    return null;
}

public SelectOption[] soWorkCountries {
    get {
        // logic that determines what work countries to return depending on activities and other parameters
    }
}

Problem

When user changes the value of the first picklist, the action is executed, but in the controller, the value of period.Activity_Type__c (see System.debug statement in the controller code), is not updated. So the right cell of the table is rerendered, but the picklist is not populated with the right values. I've tried actionregions, but this doesn't work either. What am I doing wrong here?

Answer 1

What you need to do is, pass on the desired value using apex:param in

Apex:Param is used to pass values to the controller using actionSupport. Read more: More about apex Param

Answer 2

I had a similar problem and found that using an actionFunction usually worked better. Could you try this to see if it works for you too?

Instead of doing the update and reRender with the action support, call an actionFunction instead which does the updating and reRendering.

<apex:actionSupport event="onchange" onComplete="actUpdateDynamicPicklists()" rerender="none"/>

somewhere else in your code:

<apex:actionFunction action="{!periodController.updateDynamicPicklists}" name="actUpdateDynamicPicklists" rerender="work_country"/>

Answer 3

problem with rerender attribute, below link will help you http://sfdcmaniac.blogspot.in/2015/10/passing-parameters-to-controller-and.html