Set Custom filed value to Current Assignee value using Script Listner

[sysadminEmpyra]

I am trying to write a Script Listener to copy the value from the Assignee field to a Custom field single user picker.

[sysadminEmpyra · Accepted solution]

Answer Provided from Joshua at adaptavist:

Works Perfectly 

import com.atlassian.jira.issue.Issue
import com.atlassian.jira.issue.ModifiedValue
import com.atlassian.jira.issue.util.DefaultIssueChangeHolder
import com.atlassian.jira.component.ComponentAccessor 

def issue = event.issue as Issuedef customFieldManager = ComponentAccessor.getCustomFieldManager()
def tgtField = customFieldManager.getCustomFieldObjects(event.issue).find {it.name == "My CustomField"} 
// name of your custom fielddef assignee = issue.assignee // get assignee
def changeHolder = new DefaultIssueChangeHolder()tgtField.updateValue(null, issue, new ModifiedValue(issue.getCustomFieldValue(tgtField), assignee),changeHolder) 
// set value of custom field to assignee

[Karl Samson]

The above solution is what I'm looking for to copy across the 'assignee' to a custom label field, in a Listener. But I'm getting a 'class' error for:-

"def issue = event.issue as Issuedef customFieldManager = ComponentAccessor.getCustomFieldManager()"

"...unable to resolve class 'Issuedef'"

Can anybody help?