Copy value from user picker custom field to Watchers filed on custom field update

[Nadica Gaber]

We have a request to copy values from two user picker fields to the Watcher filed whenever these fleds are updated. I have created a script listener which runs on issue update:

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 Issue
def customFieldManager = ComponentAccessor.getCustomFieldManager()
def sourceField = customFieldManager.getCustomFieldObjects(event.issue).find {it.name == "Technical Lead"}
def tgtField = customFieldManager.getCustomFieldObjects(event.issue).find {it.name == "Watchers"}
def changeHolder = new DefaultIssueChangeHolder()
tgtField.updateValue(null, issue, new ModifiedValue(issue.getCustomFieldValue(tgtField), issue.getCustomFieldValue(sourceField)),changeHolder)

But this does not update the watcher filed. We get the following error:

2017-12-13 10:21:39,209 ERROR [runner.AbstractScriptListener]: *************************************************************************************
2017-12-13 10:21:39,209 ERROR [runner.AbstractScriptListener]: Script function failed on event: com.atlassian.jira.event.issue.IssueEvent, file: <inline script>
java.lang.NullPointerException
	at com.atlassian.jira.issue.IssueImpl.getCustomFieldValue(IssueImpl.java:896)
	at com.atlassian.jira.issue.Issue$getCustomFieldValue$9.call(Unknown Source)
	at Script48.run(Script48.groovy:11

I guess that the method for get and set Watchers filed is not correct. Can you please help us with that?

Regards,

Nadica

[Ivan Tovbin]

Hi Nadica,

Indeed, the way you are trying to set the value for 'Watchers' field seems to be the problem here.

Assuming 'issue.getCustomFieldValue(sourceField)' returns an 'Application User' object, try this:

def watcherManager = ComponentAccessor.getWatcherManager()

watcherManager.startWatching(issue.getCustomFieldValue(sourceField), issue)