Mandatory input cause actionSupport to fail

Question

I want to create records from individual inputs in a table. Individual inputs are made of Users or Contacts participating to a given meeting. A Meeting__c object is the parent of User and Contacts stored in a Participant__c object. Users and Contacts are distinguished by Record Types: Internal -> Users ; External -> Contacts. Users are stored in a Lookup field User__c ; Contacts are stored in a Lookup field Contact__c. Ths user has the possibility to select the type of participant in a list box (linked to the RecordTypeID field).

Goal: render User__c or Contact__c depending on the value of the RecordTypeID selected by the user.

For that, I use an <apex:actionSupport> tag to trigger a controller method that handles the Record Type change and sets the Render variable.

Problem: I could write a page that works like expected. But as soon as I have a field required on the page, the actionSupport call fails. The Debug log shows "You must enter a value".

Diagnostic: in any case, the call goes into the checking of required fields being filled or not before doing anything else.

What I've done:

1. Enter a value in the required field: no error is raised in this case. But I can't require users to input all the required field PRIOR to entering any value in the participants list (5 fields in the final form)
2. Use immediate="true" in actionSupport
3. Use actionFunction instead of actionSupport
4. Surrounding the <apex:pageBlockTable> tag with <apex:actionRegion>tags

2 caused a different problem. 3 and 4 couldn't resolve the issue.

My question is: is there a way to call directly the controller method without triggering the required checking ?

Thank you for you help

Visualforce page:

<apex:form >
    <apex:pageBlock >

        <apex:inputField value="{!Visit.Visit_date__c}" required="false" />
        <apex:pageBlockTable value="{!Participants}" var="u" title="Participants list" id="ParticipantsList">

            <apex:column headerValue="Participant Type" >
                <apex:inputField value="{!u.participant.RecordTypeId}"  >
                    <apex:actionSupport event="onchange" action="{!onRecordTypeChange}" reRender="ParticipantsList" >
                        <apex:param name="LineIndex" value="{!u.index}" assignTo="{!CurrentRow}" />
                    </apex:actionSupport>
                </apex:inputField>
            </apex:column>       

            <apex:column headerValue="Participant" >
                <apex:inputField value="{!u.participant.User__c}" rendered="{!u.isInternal}" />
                <apex:inputField value="{!u.participant.Contact__c}" rendered="{!NOT(u.isInternal)}" />
            </apex:column>

            <apex:column headerValue="Index" >
                <apex:outputText value="{!u.index}" />
            </apex:column>                

            <apex:column headerValue="isInternal" >
                <apex:outputText value="{!u.isInternal}" />
            </apex:column>

        </apex:pageBlockTable>

    </apex:pageBlock>
</apex:form>

Answer 1

According to my understanding of your question, you want to call controller method on selection of RecordType, without entering other mandatory fields.

This can only be solved using <apex:actionSupport> inside <apex:actionRegion>.

For example

<apex:column headerValue="Participant Type">
    <apex:actionRegion>
        <apex:inputField value="{!u.participant.RecordTypeId}"  >
            <apex:actionSupport event="onchange" action="{!onRecordTypeChange}" reRender="ParticipantsList" >
                <apex:param name="LineIndex" value="{!u.index}" assignTo="{!CurrentRow}" />
            </apex:actionSupport>
        </apex:inputField>
    </apex:actionRegion>
</apex:column>

Also, if you are making fields as mandatory based on recordtype selection, for example User__c, then wrap that field within <apex:actionRegion>. Otherwise use of required="true" always fire before submitting the page.

For example

<apex:column headerValue="Participant" >
    <apex:actionRegion>
        <apex:inputField value="{!u.participant.User__c}" rendered="{!u.isInternal}" required="true"/>
        <apex:inputField value="{!u.participant.Contact__c}" rendered="{!NOT(u.isInternal)}" required="true"/>
    </apex:actionRegion>
</apex:column>