Using the Work Item Multivalue control in TFS 2017 (On premise)

Today one of my colleagues in our ALM team asked for help. For a customer we upgraded their TFS environment to TFS 2017. One of the changes we had to do along the way was replacing the existing MultiValue control by a newer version(https://github.com/Microsoft/vsts-extension-multivalue-control).

We followed the steps as mentioned here(https://github.com/Microsoft/vsts-extension-multivalue-control/blob/master/xmldetails.md) but the control didn’t appear.

Here is the template XML that we were using(I removed some content):

	<?xml version="1.0" encoding="IBM437"?>
	<witd:WITD application="Work item type editor" version="1.0" xmlns:witd="http://schemas.microsoft.com/VisualStudio/2008/workitemtracking/typedef">
	<WORKITEMTYPE name="Product Backlog Item">
	<DESCRIPTION>Tracks an activity the user will be able to perform with the product.</DESCRIPTION>
	<FIELDS>
	</FIELDS>
	<WORKFLOW>
	</WORKFLOW>
	<FORM>
	<Layout HideControlBorders="true" HideReadOnlyEmptyFields="true">
	<Group Margin="(4,0,0,0)">
	</Group>
	</Layout>
	<WebLayout>
	<!--**********************************Work Item Extensions***************************
	...
	Extension:
	Name: vsts-extensions-multivalue-control
	Id: ms-devlabs.vsts-extensions-multivalue-control
	Control contribution:
	Id: ms-devlabs.vsts-extensions-multivalue-control.multivalue-form-control
	Description: A work item form control which allows selection of multiple values.
	Inputs:
	Id: FieldName
	Description:
	Type: WorkItemField
	Field Type: String; PlainText; HTML
	Data Type: String
	IsRequired: true
	Id: Values
	Description: Values can be user provided or from suggested values of the backing field
	Data Type: String
	IsRequired: false
	Note: For more information on work item extensions use the following topic: http://go.microsoft.com/fwlink/?LinkId=816513
	-->
	<Extensions>
	<Extension Id="ms-devlabs.vsts-extensions-multivalue-control" />
	</Extensions>
	<!--**********************************Work Item Extensions*************************** -->
	<SystemControls>
	<Control Type="FieldControl" FieldName="System.Title" EmptyText="&lt;Enter title here&gt;" />
	<Control Label="Area" Type="WorkItemClassificationControl" FieldName="System.AreaPath" />
	<Control Label="Iteration" Type="WorkItemClassificationControl" FieldName="System.IterationPath" />
	<Control Label="Stat&amp;e" Type="FieldControl" FieldName="System.State" />
	<Control Label="Reason" Type="FieldControl" FieldName="System.Reason" />
	<Control Label="Assi&amp;gned To" Type="FieldControl" FieldName="System.AssignedTo" />
	<Control Label="Links" Type="LinksControl" Name="Links" />
	<Control Label="Comments" Type="WorkItemLogControl" FieldName="System.History" />
	<Control Label="Attachments" Type="AttachmentsControl" Name="Attachments" />
	</SystemControls>
	<Page Label="Details" LayoutMode="FirstColumnWide">
	<Section>
	<Group Label="Impacted Platforms">
	<ControlContribution Label="Label" Id="ms-devlabs.vsts-extensions-multivalue-control.multivalue-form-control">
	<Inputs>
	<Input Id="FieldName" Value="ImpactedPlatforms" />
	</Inputs>
	</ControlContribution>
	</Group>
	</Section>
	</Page>
	</WebLayout>
	</FORM>
	</WORKITEMTYPE>
	</witd:WITD>

view raw ProductBacklogItem.xml hosted with ❤ by GitHub

Although we couldn’t see any difference with the steps mentioned above, it didn’t work.

When I had a look I noticed that the extension is only registered in the WebLayout part of the Form.

Remark: In TFS you always had 2 layouts(a layout and a weblayout), the first one applies when opening a work item in Visual Studio or Test Manager, the weblayout applies when opening a workitem in the browser.

We first tried to add the extension to the layout part as well, but this didn’t work and resulted in some errors.

Then I had an idea, TFS 2017 offers a new Work Item experience. As mentioned here(https://www.visualstudio.com/en-us/docs/work/reference/weblayout-xml-elements) the WebLayout element is only applied on the new work item experience! This explains why our changes didn’t show up.

The new Work Item experience is an opt-in experience that should be enabled by a collection administrator. After enabling it, our Multivalue control appeared on the form…

Remark: For TFS 2017, the new form is automatically available when you add team projects to a new collection.