How to set "Start Date" in a transition?

[Stephen Casey]

I want to set a date field to indicate that an Epic was started on the date when it's transitioned to the "In Progress" status.  I've added a post function which runs the following script inline, but just can't seem to get it to work:

Script is 

import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.CustomFieldManager
import java.sql.Timestamp

def customFieldManager = ComponentAccessor.getCustomFieldManager()

def dateCf = customFieldManager.getCustomFieldObjectByName('Start Date')
issue.setCustomFieldValue(dateCf, new Timestamp((new Date()).time))

Error is: 

2018-08-08 09:27:02,168 ERROR [workflow.ScriptWorkflowFunction]: *************************************************************************************
2018-08-08 09:27:02,169 ERROR [workflow.ScriptWorkflowFunction]: Script function failed on issue: PROJECT-362, actionId: 111, file: <inline script>
java.lang.NullPointerException
	at com.atlassian.jira.issue.IssueImpl.getCustomFieldValue(IssueImpl.java:896)
	at com.atlassian.jira.issue.IssueImpl.setCustomFieldValue(IssueImpl.java:906)
	at com.atlassian.jira.issue.MutableIssue$setCustomFieldValue.call(Unknown Source)
	at Script45.run(Script45.groovy:10)

[Alexey Matveev]

Hello,

I think this line causes the error because the Start Date custom field does not exist:

def dateCf = customFieldManager.getCustomFieldObjectByName('Start Date')

 Add logging to your script like this:

import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.CustomFieldManager
import java.sql.Timestamp

def customFieldManager = ComponentAccessor.getCustomFieldManager()

def dateCf = customFieldManager.getCustomFieldObjectByName('Start Date')
log.error("dateCF: " + dateCf);
issue.setCustomFieldValue(dateCf, new Timestamp((new Date()).time))

And have a look in the atlassian-jira.log file for this erros message

[Stephen Casey]

Hi, I've taken that from other examples, if Start Date isn't there, how can I get at it to set it?  I can create a new user defined field but would prefer to re-use if possible...?

[Alexey Matveev]

You should create a custom field of the Date Time or Date picker or user any available field of this type.

You can create a custom field by going to cog item-> issues -> custom fields.

[Stephen Casey]

Start Date appears in the Custom fields already - as a Date Picker...  so I'm not sure why the above code is failing?  Set to being Global (all issues)

[Alexey Matveev]

Did you add logging to your script? If so, have a look in the atlassian-jira.log for the logged message.