# Fields Required Condition & Validator {% hint style="info" %} **Reminder:** A Condition hides the transition if criteria aren’t met, while a Validator allows the transition button to be clicked but blocks it after submission if requirements fail. {% endhint %} ## What You Get

Screenshot of the Fields Required Validator UI in Jira, showing configuration options for enforcing mandatory fields such as Linked Issues, Sub-tasks, Children, Epic, Stories, and Voters during a workflow transition.

### Make Fields Mandatory During Transitions Easily enforce required fields during a transition. You can choose from any fields available in Jira that are supported by Jira Expressions — including both system and custom fields.\ Our validator checks whether a field has been filled in either during or prior to the transition. ### Validation Messages with Dynamic Content You can display a simple message or use a Jira Expression that evaluates to a string — enabling customized, dynamic validation messages tailored to the issue context. ### Support for Additional Fields Beyond standard fields, the validator also supports additional fields compatible with Jira Expressions

Field name	Workflow Building Blocks	Out-of-the-box
Epic	true	❌
Voters	true	❌
Stories*	true	❌
Children*	true	❌
Closed Sprints	true	❌
Linked Issues*	true	❌
Sub-tasks	true	❌
Work Logs*	true	❌
Original Estimate*	true	❌ Ignored
Remaining Estimate*	true	❌ Ignored
Time Spent	true	☑️ Only during transition
Attachments*	true	☑️ Only during transition
Comment*	true	☑️ Only during transition

* Stories – Check if an Epic has any direct child work items, excluding sub-tasks. * Children – Check if a work item has any direct children, including sub-tasks. * Epic – Check if a work item belongs to an Epic. * Linked Issues (Related Work Items) – Check if the issue has any links to other issues. * Work Logs – Check if any work log has been added before the transition. *(Note: work logs are not created during the transition itself)* * Original Estimate – Ensure an estimate is provided before or during the transition, and that it is not equal to 0. * Remaining Estimate – Ensure a remaining estimate is provided before or during the transition, and that it is not equal to 0. * Attachments – Check if any attachment has been added either before or during the transition. * Comment - Check if any comment has been added either before or during the transition. ### Handling of Already Added Attachments The **Fields Required Validator** from the **Workflow Building Blocks** app checks whether an attachment has been added **before** the transition or **during** the transition (via a Transition Screen). In contrast, the **classic built-in Field Required Validator** only enforces that an attachment is added **during** the transition, ignoring any attachments already present. {% hint style="info" %} In the **New Workflow Editor**, you can enforce required fields using the **“Validate a field”** rule with the **“Isn’t Empty”** option. Both out-of-the-box validators behave the same way in this regard. {% endhint %} Which validator should you use? * ✅ Use the Fields Required Validator **from our app** if the attachment can be added **at any point earlier in the workflow** (not necessarily during the current transition). * ✅ Use the **classic validator** if the attachment must be added **specifically during the current transition**.