Jira Service: Is it possible to create a transition validator that blocks the user from the project

[Diana Osorio]

I need to create a validator, which if the project role is an external type user, can only allow the transition if the "a" field is blank, if this field is filled it cannot be transitioned. If the project role user is another, you can only transition if the "a" field has been filled in. Is it possible?

[Maciej Dudziak _Forgappify_]

Hi @Diana Osorio

I think that described case can be addressed using a Jira expression-based validator. There are several options available on the Atlassian marketplace.

I am from Forgappify, and we developed Jira Expression Validator, which is part of the Workflow Building Blocks for Jira app.

The expression you need could look as follows:

user.getProjectRoles(issue.project).reduce(
  (isAllowed, role) => isAllowed || ["External"].includes(role.name),
  false
) ? issue.customfield_12334 == null : issue.customfield_12345 != null

Put the name of your project role in place of "External". You also need to change customfield_12334 to your field ID. In the expression editor, when you start typing the name of your field, you will get a suggestion for the ID. 

Condition may slightly differ depending on type of your field.

I hope it will help.

Cheers