Workflow condition or validator to enforce a custom text field as mandatory on the fly

Would it possible to enforce a custom text field as mandatory on the fly on issue type create screen, when a user selects a value ‘Yes’ from a single select dropdown field?

Could you please help me with a javascript code that may be included in the workflow status transitions in post functions or some applicable place on Jira cloud instance that has no third party addons?

iI should be possible to write a Connect app with a workflow validator that does this. The validator could check values of both fields and expect different results depending on the value of the single select dropdown field.

Thanks for your response. Would you mind, pointing me in a direction on how to write one or share a link that probably had this code written, as I did not follow quite well with reference link that you gave.

A good place to start would be to follow this tutorial on how to write Connect apps:

Then there is an example validator app linked in the docs: You should be able to just clone it and run to play around with to see how validators work. Then it’s just a matter of replacing the expression in that app with one that suits you.

In fact, that example is probably much more complicated than you need. If you are not interested in configuring the validator during configuration, the only thing you need is an entry in your descriptor, without any callbacks to “create”, “edit” or “view” (just skip these properties).

Let me know if you have any questions.

Thanks @kkercz for these references. We probably getting off of cloud instance sometime sooner or later, so I think we may have to hold off onto this for now until and unless we know the path moving forward.