Validate TFS 2017 Boolean field - tfs

Question

I am trying to edit work item templates to make use of the new Boolean field in TFS 2017, and want a particular field to be set to true before a status can be changed. Is there any way to do this? It would appear ALLOWEDVALUES and MATCH aren't supported, which could have potentially helped

Answer 1

You can do that by applying a conditional rule based on your requirement just as Hamid mentioned above.
Boolean is just a data type, we can add a custom Boolean field and add a checkbox for it.
Use the following syntax to add a Boolean field within the FIELDS
section of the WIT definition.
<FIELD name="Triagelc" refname="lc.Triage" type="Boolean" >
<DEFAULT from="value" value="True" />
<HELPTEXT>Triage work item</HELPTEXT>
</FIELD>
And then add the following syntax within the FORM section to have
the field appear on the form.
<Control Label="Triagelc" Type="FieldControl" FieldName="lc.Triage" />
The field will appear as a checkbox on the form.
Then apply a When rule for target filed, thus when the specified
Boolean field has the specified value, the When rule is applied to
the target field.
eg1:
Apply a "When" rule for Description field in Task work item type :
<FieldDefinition name="Description" refname="System.Description" type="HTML">
<WHEN field="lc.Triage" value="True">
<REQUIRED />
</WHEN>
</FieldDefinition>
Then when set the value to True, the Description area is required, it cannot be empty.
eg2:
You can also use READONLY rule to restrict other areas:
<FieldDefinition name="Assigned To" refname="System.AssignedTo" type="String" syncnamechanges="true" reportable="dimension">
<WHEN field="lc.Triage" value="True">
<READONLY />
</WHEN>
<ALLOWEXISTINGVALUE />
<HELPTEXT>The person currently owning this task</HELPTEXT>
</FieldDefinition>
Thus, when the Boolean field value is True, Assigned To field is read only, otherwise you can assign to the existing users.
UPDATE:
eg3:
We can not achieve that directly with the boolean data type. As a workaround you can try below ways:
Apply the When rule and embed the Copy rule (Copy True as the
value) for the "Triagelc" boolean field in this example. Thus when
the status is Done, Triagelc can set the value to "True"
automatically, then save. But in this way the value still can be
modified to false. Reference below screenshot 1:
<FieldDefinition name="Triagelc" refname="lc.Triage" type="Boolean">
<WHEN field="System.State" value="Done">
<COPY from="value" value="True" />
</WHEN>
<HELPTEXT>Triage work item</HELPTEXT>
</FieldDefinition>
Set the default value to True for Boolean field (Triagelc
field in this example), then apply When rule with READONLY rule
embedded. This way should be meet your requirement (Once done the value cannot be changed anymore). Reference below screenshot 2:
<FieldDefinition name="Triagelc" refname="lc.Triage" type="Boolean">
<DEFAULT from="value" value="True" />
<WHEN field="System.State" value="Done">
<READONLY />
</WHEN>
<HELPTEXT>Triage work item</HELPTEXT>
</FieldDefinition>
Please note that:
The Boolean data type field is only supported for VSTS and TFS 2017.2
and later versions.
Screenshot 1:
Screenshot 2: