I have added 2 custom fields in JIRA namely
1. 'Link to Knowledge Base Requied?' -> This is a Yes/No/Not-sure dropdown box
2. 'Link to Knowledge Base' -> this is an url field where the user will paste a url
Requirement: I need to ensure that the second field i.e 'Link to Knowledge Base' is NOT blank when the value of first field i.e 'Link to Knowledge Base Requied?' is selected as 'Yes', before closing the issue. However, when either 'No' or 'Not Sure' is selected in the dropdown box, the issue can be closed regardless of the value in custom field.
I checked your documentation in https://confluence.atlassian.com/display/JIRA/Configuring+Workflow#ConfiguringWorkflow-Addingavalidator. But this does not serve my purpose. I can check a field's value before closing the issue. But what I need here is to Close the issue only if the first dropdown box's value is selected as 'Yes'. How can I do that? Any thoughts?