Change subtask assignee based on parent WITHOUT post function

unknown

Usage: I have an issue with a dozen subtasks. I wan to change the assignee of the issue to someone else and have all of the subtasks automatically update as well, however, I do not want to create a workflow item to do this. Our workflow is already pretty complex as it is.

I don't really have the knowledge to create my own plugin or figure out the event listeners. My thinking was to use the script runner to have the escalation service work off of the following JQL query. Honestly I'd rather not use the service since its sitting there checking every x number of minutes, but if it works, I'll take it:

('Subtask Follow' = 'Yes') AND (Status != 'Closed') AND ('assignee' CHANGED)

Subtask follow is basically a field that lets the user decide if they want the assignement change to affect all the subtasks. Here's the gist of the script I envisioned (that obviously doesn't work..):

issue.subtask.assignee == issue.assignee

I've tried a variety of other scripts based on my searches, but I just don't know enough to really understand what the problem is. Seems like this should be simple enough and useful enough...

unknown

package com.atlassian.jira.event.listeners

import com.atlassian.jira.event.issue.AbstractIssueEventListener
import com.atlassian.jira.event.issue.IssueEvent
import com.atlassian.jira.event.type.EventDispatchOption
import com.atlassian.jira.issue.MutableIssue
import com.atlassian.jira.issue.Issue
import com.atlassian.jira.issue.CustomFieldManager
import com.atlassian.jira.issue.fields.CustomField
import com.atlassian.jira.issue.IssueManager
import com.atlassian.jira.issue.IssueInputParameters
import com.atlassian.jira.issue.changehistory.ChangeHistoryManager
import com.atlassian.jira.issue.history.ChangeItemBean
import com.atlassian.jira.ComponentManager
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.user.util.UserManager
import org.apache.log4j.Category
import org.apache.log4j.Level
import org.apache.log4j.Logger

public class SubtaskAutoAssignListener extends AbstractIssueEventListener {
    Category log = Category.getInstance(SubtaskAutoAssignListener.class)
 
    @Override
    void workflowEvent(IssueEvent event) {
        log.error("\n \n \n \n ---- Assignee Updater starts -----  \n \n \n \n \n")
		CustomFieldManager customFieldManager = ComponentManager.getInstance().getCustomFieldManager()
		def customField_Follow = customFieldManager.getCustomFieldObjectByName( "Subtask Follow" )
		def subtaskFollow = event.issue.getCustomFieldValue(customField_Follow)
		log.error("\n \n \n Assign subtask to parent assignee?: $subtaskFollow \n \n")
		if ("$subtaskFollow" == "Yes") {
			if (!event.issue.isSubTask()){
				def issueAssigneeId = event.issue.getAssigneeId()
				log.error("\n \n \n Parent Issue Assignee: $issueAssigneeId \n")

				IssueManager issueManager = ComponentAccessor.getIssueManager()
				UserManager userManager = ComponentAccessor.getUserManager()

				event.issue.getSubTaskObjects().each { t ->
					log.error("\n \n \n Subtask ID: $t \n \n \n")
					def subtaskAssignee = t.getAssigneeId()
					log.error("\n \n \n Current subtask assignee: $subtaskAssignee \n \n \n")
					if (!subtaskAssignee.equals(issueAssigneeId)) {
						MutableIssue myIssue = t
						myIssue.setAssigneeId(issueAssigneeId)
						issueManager.updateIssue(userManager.getUser(issueAssigneeId),myIssue,EventDispatchOption.DO_NOT_DISPATCH, false)
						def newSubtaskAssignee = myIssue.getAssigneeId()
						log.error("\n \n \n New subtask assignee: $newSubtaskAssignee \n \n \n")
					}
				}
			}
		}
		log.error("\n \n \n \n ---- Assignee Updater Ends -----  \n \n \n \n \n")
    }
}