Restrict type of subtask that can be created for a given parent type

[Chris Bland]

Hi, I'm fairly new at this. There seem to be a variety of approaches - some guidance as to what would be best would very helpful.

This is for a plugin we are developing. We have two custom issue types, A and B (a subtask).

A will only have subtasks of type B. Equally, type B subtasks will only be able to have a parent of type A.

I would like us to be able to restrict the creation of subtasks, to achieve this.

Preferably, in the Create Subtask Issue Type dropdown, I would like to get rid of all other choices. 

However, if I have to use validation, then a message telling the user to pick another type, this would be OK.

Has anyone got some thoughts on the best way to achieve this?

Many thanks.

[BenP]

See https://jira.atlassian.com/browse/JRA-7990, where Denis Yaparov has provided a nice solution via (script runner) simple validation on Create issue transition's validator event

This simple scripted validator on Create transition in sub-issue workflow could do required check:

["Task", "Bug"].contains(issue.parentObject?.issueTypeObject.name)

[Bob Swift OSS (Bob Swift Atlassian Apps)]

You can certainly do that with a validator like Conditioned validator from Update on Transition for JIRA. It would just give a use message when something you don't want was tried. It doesn't prevent the option from showing up.
I suspect there may be easier or more complete ways to do this, but I don't know off hand. 

[Chris Bland]

Thanks for that - this is going into a plugin for the marketplace, so we really need it to be in code, with the minimum of dependencies.

[Bob Swift OSS (Bob Swift Atlassian Apps)]

Oh, sorry, I missed that in my reading. I don't really have a suggestion then.

[Chris Bland]

I should have made that clearer - thanks for responding though.