Working with Field Rules
Depending on the data type of a field, you can set various restrictions on what data can be entered into that field. For example, you can define a default value, restrict what values users can specify, and restrict who can update the value of the field. You may want to apply a rule to a work item field for one or more of the following reasons:
Specify the tooltip text that appears when a user hovers over a field in a work item form.
Require the value of a string field to match a pattern.
Make a field required or read-only, or make sure that it does not contain the same value as another field.
Clear a field, or restrict further modifications of a field.
Restrict who can modify the field.
Apply a rule to a field when the value of another field has changed or is assigned a specific value.
You can apply multiple rules to a field. If you include rules within a FIELD (Definition) element, the rules always apply. If you include them within the FIELD (Workflow) element, you can scope them to apply during a change in state, during a transition to a state, or when a user specifies a reason for a transition.
Common Tasks
Tasks |
Related topics |
|---|---|
Enforce rules always, during a transition, when a user changes the state, or when a user specifies a reason. You can use field rules to control the behavior of a type of work item regardless of its state. For example, a field that is required for a bug when it is new and active remains required until the bug is closed. |
|
Apply rules that control the value of a work item field. You can restrict how the value of a field can change if you specify a qualifying rule, such as the CANNOTLOSEVALUE, EMPTY, FROZEN, NOTSAMEAS, READONLY, and REQUIRED elements. |
|
Define the help text for a work item field. You can customize the help text or tooltip text that appears when a user points to a field that appears on a work item form. Help text is restricted to 255 Unicode characters and can be localized. |
|
Restrict who can modify a field. You can restrict who can modify a field in a work item by using the VALIDUSER element. |
|
Define the pattern that a string value must match. You can use the MATCH element to enforce a pattern on the contents of a string field. |
|
Copy a value into a field. You can specify a default value for a field, or you can copy the value from another field or system-defined value. You can assign a field default by using one of the following elements: COPY, DEFAULT, and SERVERDEFAULT. |
|
Use tokens for attributes that reference users or groups. When you restrict a rule to a user or group, you must indicate the domain or scope of the group. For some values, you can use tokens. |
|
Limit a rule to apply or not apply to a specific group. You can qualify most rules to apply or not apply to a set of groups or users if you include the for or not attributes. |
|
Specify conditions on field value assignments based on values in other fields. You can define rules that are run conditionally if you use the WHEN, WHENNOT, WHENCHANGED, and WHENNOTCHANGED elements. |
|
Understand how rules are processed. Rules are typically processed in the sequence in which they are listed. However, when you use the WHEN*, DEFAULT, and COPY elements, additional behaviors may apply. |
See Also
Concepts
All WITD XML Elements Reference