To create pages that perform mass updates, use the prototype object contained in the StandardSetController class.
The list controller tracks two sets of records: a primary list containing all the records selected by the filter, and a secondary list containing those records the user selected. The secondary list is usually established on a standard listview page where the user can check boxes to select the records. The user can then click on a custom list button that navigates to your custom mass update page, which uses the prototype object to apply new field values to the user's selection. The prototype object operates on all the records in the user's selection. To retrieve the prototype object in your custom controller, use the StandardSetController's getRecord method. For example, to enable mass updates for Opportunities, use the singular term for its associated object (Opportunity) to set field values for all records in the selection:
public class selectedSizeWorkaround { ApexPages.StandardSetController setCon; public selectedSizeWorkaround(ApexPages.StandardSetController controller) { setCon = controller; } public integer getMySelectedSize() { return setCon.getSelected().size(); } public integer getMyRecordsSize() { return setCon.getRecords().size(); } }
<apex:page standardController="Opportunity" recordSetVar="opportunities" extensions="selectedSizeWorkaround" showHeader="false" id="muopp" > <apex:form id="muform"> <apex:pageMessage summary="Selected Collection Size: {!mySelectedSize}" severity="info" id="mupms" /> <apex:pageMessage summary="Record Set Size: {!myRecordsSize}" severity="info" id="mupmr" /> <apex:pageBlock title="Opportunity Mass-Update" mode="edit" id="mub1"> <apex:pageMessages /> <apex:pageBlockSection id="mus1"> <apex:inputField value="{!opportunity.stagename}" id="stagename"> <apex:actionSupport event="onchange" rerender="muselectedlist"/> </apex:inputField> </apex:pageBlockSection> <apex:pageBlockButtons location="bottom" id="mubut"> <apex:commandButton value="Save" action="{!save}" id="butsav"/> <apex:commandButton value="Cancel" action="{!cancel}" id="butcan"/> </apex:pageBlockButtons> </apex:pageBlock> <apex:pageBlock title="Selected Opportunities" id="muselectedlist"> <apex:pageBlockTable value="{!selected}" var="opp" id="mutab"> <apex:column value="{!opp.name}" id="oppname"/> <apex:column value="{!opp.stagename}" id="oppstage"/> </apex:pageBlockTable> </apex:pageBlock> </apex:form> </apex:page>
While this example shows you how to update one field, any number of fields in the prototype object can be referenced and applied to the user's selection; any field in the prototype object that the user doesn't set doesn't affect the selected records. Remember that properties of fields, such as their requiredness, are maintained in the prototype object. For example, if you include an input field on the page for a required field such as Opportunity.StageName, the user must enter a value for the field.