Post-function script that adds user to a group

[QTR]

Hi,

Perhaps someone can help me with following, I'm trying to create a transition post-function that adds user to a group (from a user picker custom field). However, when running below script...

import com.atlassian.crowd.embedded.api.User
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.user.ApplicationUser

def groupManager = ComponentAccessor.getGroupManager()
def user = (ApplicationUser) ComponentAccessor.getCustomFieldManager().getCustomFieldObjectByName("Field Name").getValue(issue)

def group = groupManager.getGroup("Group1")

groupManager.addUserToGroup(user,group)

...I get this error

019-10-24 22:36:14,574 ERROR [workflow.ScriptWorkflowFunction]: *************************************************************************************
2019-10-24 22:36:14,575 ERROR [workflow.ScriptWorkflowFunction]: Script function failed on issue: ISSUE-66, actionId: 11, file: <inline script>
org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object '[user@user.com)]' with class 'java.util.ArrayList' to class 'com.atlassian.jira.user.ApplicationUser' due to: groovy.lang.GroovyRuntimeException: Could not find matching constructor for: com.atlassian.jira.user.ApplicationUser(com.atlassian.jira.user.DelegatingApplicationUser)
 at Script74.run(Script74.groovy:6 

[Jack Nolddor _Sweet Bananas_]

Hi QTR,

The problems is in:

ComponentAccessor.getCustomFieldManager().getCustomFieldObjectByName("Field Name").getValue(issue)

since this doesn't return an (ApplicationUser) but a List<ApplicationUser> you must then ensure that this value isn't return as null and iterate over each element calling the groupManager.addUserToGroup(user,group) for each eleement to add it to the desired group.

Regards