Define a default value or copy a value to a field

Artikel
04/20/2015

You can specify a default value for a field, or you can copy the value from another field or system-defined value. Field defaults are rules that control how field values are automatically assigned. You can assign a field default by using one of the following elements: COPY, DEFAULT, and SERVERDEFAULT. You can specify these elements as child elements of the FIELD (Definition) element or the FIELD (Workflow) element.

You add these elements to the definition for a work item type (WIT). To learn more, see Modify or add a custom work item type (WIT).

The COPY and DEFAULT elements fill in values at the start of editing, but the SERVERDEFAULT rule fills in a value when the work item is committed to the database. This action occurs when a user saves changes to a work item, and the user cannot override the value. Such fields usually appear as read-only on the work item form. The SERVERDEFAULT rule is used for fields such as "Last Changed By" and "Last Changed On" to support secure audit trails.

Syntax

You can use the COPY, DEFAULT, and SERVERDEFAULT elements to copy a value from one field to another, copy a server value into a field, or specify a default value to be defined for a field.

Note

If the work item is being changed, the COPY or DEFAULT elements rule may select either the current or previous value from the source field.

You can specify a value to copy from another field, the value of the clock, or the name of the current user. If you specify value or field for the from attribute, you must specify the value or field attribute. When a user changes or creates a work item, the COPY rule fills in a field value regardless of any value that is already in the field.
```
<COPY for="userGroupName" not="userGroupName"  from="value | field | clock | currentuser" value="valueToCopy" field="fieldReferenceName/>
```
You can specify a default value for a field by using the DEFAULT rule. When a user creates or edits a work item, the DEFAULT rule fills in a value if that field is empty. You can specify a value to copy from another field, the date-time stamp that the server clock records, or the name of the current user. If a field already has a value, this rule is ignored.
```
<DEFAULT for="userGroupName" not="userGroupName" from="value | field | clock | currentuser" value="defaultValue" field="fieldReferenceName" />
```
You can specify a value to copy from the server into a field when the work item is saved. When a user changes the state of a work item, the SERVERDEFAULT rule specifies a value to be copied into the current field from a value that is derived from a server component. The DEFAULT and COPY elements fill in values when a user opens a work item to modify it, but the SERVERDEFAULT rule fills in a value when the work item is committed to the database. This action occurs when the user saves the work item. The user cannot override the value. These fields usually appear as read-only on the form. The SERVERDEFAULT rule is used for fields such as "Last Changed By" and "Last Changed On" to support secure audit trails.
```
<SERVERDEFAULT for="userGroupName" not="userGroupName" from="clock | currentuser" />
```

Each of these rule elements specifies a from="fromType" attribute that identifies the source of the value. Depending on the fromType value, additional attributes may be required. The following table describes all of the attributes that the COPY, DEFAULT, and SERVERDEFAULT rule elements reference.

Attribute	Description
for	Optional. Specifies the name of a user or group in Team Foundation to whom the rule applies. Valid names consist of a string of text that contains between 1 and 255 characters. Pattern value: ^[^\\]+\\[^\\]+$ Pattern value example: Domain\UserID
not	Optional. Specifies the name of a user or group in Team Foundation to whom the rule does not apply. Valid names consist of a string of text that contains between 1 and 255 characters. Pattern value: ^[^\\]+\\[^\\]+$ Pattern value example: Domain\UserID
from	Required. Specifies whether to copy the default value from the value attribute, the field attribute, the system clock, or the current user. If you specify value or field for the from attribute, you must specify the value or field attribute, respectively. You can specify the following values: clock: Copies the time from the system clock. Uses the current date and time as the value. No additional attributes are required. For the COPY and DEFAULT rules, the value is taken from the local computer clock. For the SERVERDEFAULT rule, the value is taken from the server clock at commit time. Valid only for DateTime fields. currentuser: Copies name of the user who is logged on. Use the short user name of the current user as the value. No additional attributes are required. Valid only for string fields. field: Copies the value that is defined for the field attribute that you specify. Requires a field="abc" attribute. By default, if the specified "from" field is empty, nothing is performed. The field attribute is used only for the COPY and DEFAULT rules. value: Copies the value of the specified value attribute.
value	Optional. Specifies the value to be copied into the field when value is specified for the from attribute. Valid values consist of a string of text that contains between 1 and 255 characters. The value to copy can be empty.
field	Optional. Specifies the name of the field whose value is to be copied into the field when field is specified for the from attribute. You must define this attribute if the from attribute has "field" as its value. The reference name of the field to copy. The reference name must match the reference name as defined in the FIELD (Definition) element. For more information, see FIELD (Definition) element reference. Pattern value: ^[a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z0-9_]+)+$ Pattern value example: Company.Division.IssueType