I have a situation where I have an optional lookup (PO Line Item) and a master detail field (Sub Account) on an Invoice record.  The PO Line Item object also links to a Sub Account and I want to default this Sub Account value from a selected PO Line Item into the Invoice's Sub Account field.  You don't always have to choose a PO Line Item; in the case that there is no PO you simply select a Sub Account manually.

To accomplish this I have an actionSupport component that calls a controller method onchange to run SOQL on the selected PO Line Item to pull its Sub Account into the invoice's Sub Account field.  The user is picking a PO Line Item before they have set a Sub Account, thus that MD field is blank when they select a PO Line Item.  This gives a validation error when the action function runs.  

To avoid the error, I added ActionRegion tags around the PO Line Item field so that only the PO Line Item value is sent.  But this means the rest of the data that I have entered so far is lost in the rerender.

Any thoughts on how to accomplish this - avoid the error on requiring a value in an MD field but keep the values in all the other fields after the rerender?

I have a situation where I have an optional lookup (PO Line Item) and a master detail field (Sub Account) on an Invoice record.  The PO Line Item object also links to a Sub Account and I want to default this Sub Account value from a selected PO Line Item into the Invoice's Sub Account field.  You don't always have to choose a PO Line Item; in the case that there is no PO you simply select a Sub Account manually.

To accomplish this I have an actionSupport component that calls a controller method onchange to run SOQL on the selected PO Line Item to pull its Sub Account into the invoice's Sub Account field.  The user is picking a PO Line Item before they have set a Sub Account, thus that MD field is blank when they select a PO Line Item.  This gives a validation error when the action function runs.  

To avoid the error, I added ActionRegion tags around the PO Line Item field so that only the PO Line Item value is sent.  But this means the rest of the data that I have entered so far is lost in the rerender.

Any thoughts on how to accomplish this - avoid the error on requiring a value in an MD field but keep the values in all the other fields after the rerender?

In my pageBlockTable, when the "Quantity" is changed, it would be a action and reRender this table,

when the table is rerenderd, the focus in this table would be lost, so i'm trying to re-focus the last element.

here is my code:

<apex:page controller="Mycontroller">
<script type="text/javascript">
   var elementFocus = null;
   function setFocus(){
       elementFocus = document.activeElement;
   }
   function retainFocus(){
       elementFocus.focus();
   }
</script>
 <apex:form >
   <apex:pageBlock>
      <apex:pageBlockTable value="{!wrappers}" var="wrapper" id="wtable">
         <apex:column headerValue="Quantity">
             <apex:inputField value="{!wrapper.sub.Quantity__c}" id="Quantity__c">
                 <apex:actionSupport event="onchange" action="{!doSomething}"

                     <!-- before take action, set current focus. oncomplete, retain that focus -->
                     onbeforedomupdate="return setFocus()" rerender="wtable" oncomplete="return retainFocus()">
                 </apex:actionSupport>
             </apex:inputField>
         </apex:column>
         <apex:column headerValue="SalesPrice">
            <apex:inputField value="{!wrapper.sub.SalesPrice__c}" id="SalesPrice__c"/>
         </apex:column>
      </apex:pageBlockTable>
   </apex:pageBlock>
 </apex:form>
</apex:page>

 i use javascript to retain focus, and the alert also shows the right id, but elementFocus.focus(); just don't work.

should i include some other script?

<script type="text/javascript">
   var elementFocus = null;
   function setFocus(){
       elementFocus = document.activeElement;
       alert(elementFocus.id);
   }
   function retainFocus(){
       alert(elementFocus.id); //when debug, it shows the same value as the id in setFocus()
       elementFocus.focus();
   }
</script>

 Any help would be much appreciated!

HI

I have a page that needs to do the occasional calculation then show the results afterwards which entails a section of the page to be rerendered. If the focus was within the rerendered area then the focus is lost. I want to put it back. I am aware that a lot of components that have an Action attribute also have a Focus attribute. Problem is I can't figure out how to tell it to return the focus to where it was. I am hoping that there is something like this:

focus="{!$CurrentPage.getComponentID.CurrentFocus}"

That would make life so easy. Not afraid of APEX or Javascript if they present a solution. Any and all help appreciated.

Regards

MellowRen