App developers can implement this interface to specify Apex code that runs automatically after a subscriber uninstalls a managed package. This makes it possible to perform cleanup and notification tasks based on details of the subscriber’s organization.
The uninstall script is subject to default governor limits. It runs as a special system user that represents your package, so all operations performed by the script will appear to be done by your package. You can access this user by using UserInfo. You will only see this user at runtime, not while running tests.
If the script fails, the uninstall continues but none of the changes performed by the script are committed. Any errors in the script are emailed to the user specified in the Notify on Apex Error field of the package. If no user is specified, the uninstall details will be unavailable.
The uninstall script has the following restrictions. You can’t use it to initiate batch, scheduled, and future jobs, to access Session IDs, or to perform callouts.
global interface UninstallHandler { void onUninstall(UninstallContext context)};
global interface UninstallContext { ID organizationId(); ID uninstallerId(); }
The following are methods for UninstallHandler.
The sample uninstall script below performs the following actions on package uninstall.
global class UninstallClass implements UninstallHandler { global void onUninstall(UninstallContext ctx) { FeedItem feedPost = new FeedItem(); feedPost.parentId = ctx.uninstallerID(); feedPost.body = 'Thank you for using our application!'; insert feedPost; User u = [Select Id, Email from User where Id =:ctx.uninstallerID()]; String toAddress= u.Email; String[] toAddresses = new String[] {toAddress}; Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); mail.setToAddresses(toAddresses); mail.setReplyTo('support@package.dev'); mail.setSenderDisplayName('My Package Support'); mail.setSubject('Package uninstall successful'); mail.setPlainTextBody('Thanks for uninstalling the package.'); Messaging.sendEmail(new Messaging.Email[] { mail }); } }
You can test an uninstall script using the testUninstall method of the Test class. This method takes as its argument a class that implements the UninstallHandler interface.
@isTest static void testUninstallScript() { Id UninstallerId = UserInfo.getUserId(); List<FeedItem> feedPostsBefore = [SELECT Id FROM FeedItem WHERE parentId=:UninstallerId AND CreatedDate=TODAY]; Test.testUninstall(new UninstallClass()); List<FeedItem> feedPostsAfter = [SELECT Id FROM FeedItem WHERE parentId=:UninstallerId AND CreatedDate=TODAY]; System.assertEquals(feedPostsBefore.size() + 1, feedPostsAfter.size(), 'Post to uninstaller failed.'); }