If a user enters data on a Visualforce page that uses a custom controller, and that data causes a validation rule error, the error can be displayed on the Visualforce page. Like a page that uses a standard controller, if the validation rule error location is a field associated with an <apex:inputField> component, the error displays there. If the validation rule error location is set to the top of the page, use the <apex:messages> component within the <apex:page> to display the error. However, to get the information to the page, the custom controller must catch the exception.
<apex:page controller="MyController" tabStyle="Account"> <apex:messages/> <apex:form> <apex:pageBlock title="Hello {!$User.FirstName}!"> This is your new page for the {!name} controller. <br/> You are viewing the {!account.name} account.<br/><br/> Change Account Name: <p></p> <apex:inputField value="{!account.name}"/> <p></p> Change Number of Locations: <apex:inputField value="{!account.NumberofLocations__c}" id="Custom_validation"/> <p>(Try entering a non-numeric character here, then hit save.)</p><br/><br/> <apex:commandButton action="{!save}" value="Save New Account Name"/> </apex:pageBlock> </apex:form> </apex:page>
public class MyController { Account account; public PageReference save() { try{ update account; } catch(DmlException ex){ ApexPages.addMessages(ex); } return null; } public String getName() { return 'MyController'; } public Account getAccount() { if(account == null) account = [select id, name, numberoflocations__c from Account where id = :ApexPages.currentPage().getParameters().get('id')]; return account; } }