---
title: "Validators"
canonical: "https://support.appfire.com/space/JMWE/78123903/Validators"
format: markdown
---
> Macro (toc)
#### 1 - Field has been modified Validator *(new in 1.3)*
A validator that forces users to modify a field during a transition.
#### 2 - Field is Required Validator *(new in 3.1.1)*
A validator that forces a field to have a value during a transition. You can optionally customize the error message displayed if the field has no value. Naturally, the transition needs to be associated with a transition screen for the error message to be displayed.
#### 3 - Comment Required Validator
A validator that forces users to enter a comment during a transition. If they don't, a customized error message will be displayed.
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Note that this validator is disabled if the transition is being made through SOAP because the progressWorkflowAction method does not let you specify a comment.
#### 4 - Field has single value Validator
A workflow validator that checks that a multi-valued field does not contain more than one value during a transition. This can be useful, for example, to make sure users don't select more than one "Fix version" during the *Resolve* transition.
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Option "Excluding values copied from sub-tasks" is a bit more complex. During the single-valuation test, it will make the validator ignore values that are associated with the issue's sub-tasks, if any. For example, if the issue has one sub-task, and this sub-task's *Fix version(s)* is "1.0", then a *Fix version(s)*'s value of "1.0, 2.0" will be acceptable during the issue's transition (because "1.0" will be ignored).
#### 5 - Previous Status Validator
A validator that does basically the same thing as the Previous Status Condition above.
#### 6 - Parent Status Validator
A workflow validator that ensures that the current issue's parent issue is in one of the specified Statuses. This is useful only for sub-tasks.
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