Working with Link Types
You use a link type to define the link labels, topology type, and restrictions that are used when links between work items are constructed. For example, the parent-child link type defines two labels (Parent and Child), supports a hierarchical or tree topology, and prevents circular references from being created between work items.
To customize or create a link type, you import an XML file to the team project collection that contains the definition for the link type. Link types are added to the set of link types that are defined for the collection. Existing link types are overwritten with the new information based on the reference name that you specify.
You can define additional link types by adding them to the link types that are defined for a team project collection. You can define valid link types for use in your process based on the structure that the link type definition schema provides. A link type is defined by the following XML syntax in the link types XML file:
<LinkTypes> <LinkType ReferenceName="LinkTypeName" ForwardName="ForwardName" ReverseName="ReverseName" Topology="TopologyType" /> </LinkTypes>
The descriptions in the following table apply to the previous syntax:
Name of the link type. This name is used internally when you create a link between two work items.
Name of the link at the source work item. This name appears when you add links to the source work item.
Name of the link at the target work item. This name appears when a listing of the links at the target work item appears.
Specifies the DirectedNetwork, Network, Tree, or Dependency topology. The first three topologies are directional, and you use them to define subordinate or sequential relationships. You use Network to define relationships between peers or where no implied subordination exists.
Link directionality is determined by the assignments made to the ForwardName and ReverseName attributes. If you create a custom link and assign the same name to the forward and reverse names, you should set the link type to Network because it is the only non-directional topology.
LINKTYPES is a set of LINKTYPE elements that are stored and used by a team project collection.
Each link type has a reference name and two optional friendly names, or name labels, which must be unique within the project collection. Each link type name must meet the following requirements:
Names can have up to 254 Unicode characters.
Names must not be empty.
Names cannot have leading or trailing white spaces.
Names cannot contain backslash (\) characters.
Names cannot contain two consecutive white spaces.
The following table summarizes the link types that are defined by the system. These link types should not be overwritten or modified in any way.
Link type reference name
The following table lists the link types that are created when you create a team project by using a Microsoft Solutions Framework (MSF) process template. These link types are specifically designed to support interaction with tracking work items in Team Foundation and Microsoft Test Manager.
Link type reference name
Each of the link types listed earlier in this topic are added to the team project collection when you use an MSF process template to create a team project. Link type definition files are defined in the WorkItem Tracking\LinkTypes folder of the Template.zip file. The following definition for the Microsoft.VSTS.Common.TestedBy link type is defined in the TestedBy.xml file:
<?xml version="1.0" encoding="utf-8"?> <LinkTypes> <LinkType ReferenceName="Microsoft.VSTS.Common.TestedBy" ForwardName="Tested By" ReverseName="Tests" Topology="Dependency" /> </LinkTypes>
When you create the team project by using the corresponding process template, the link type definition is imported into the project collection.
The topology that is assigned to a link type determines the restrictions that are added for its usage. In the following table, you can view the different topology types:
Network: You can use network links to create basic relationships between work items that are non-restrictive. The link is the same at both end points. Circular relationships are allowed.
Example usage: Use a network link, such as Related, to record a relationship between two features that might share dependencies.
Directed Network: You can use directed network links to create relationships between work items that indicate directionality. The link name is different at the end points. Circular relationships are allowed.
Example usage: Use a directed network link to record a relationship between two features that might share dependencies and which you want to distinguish from each other in some way.
Dependency: You can use dependency links to create relationships between work items that have directionality and to restrict circular relationships. The link name is different at the end points.
In the illustration, you cannot create a dependent link to a work item that contains dependent link relationships to the same work items.
Example usage: Use a dependency link to record the features that must be completed to deliver a user requirement.
Tree: You can use tree links to create multi-level hierarchical relationships among work items. Tree links support multi-level hierarchical views, have directionality, and restrict circular relationships. The link name is different at the end points. Tree links are the only type of link that is supported by the Tree of Work Items query.
In the illustration, you cannot assign two parents to a child.
Example usage: Use a tree link to record tasks and subtasks from your team that must be completed to deliver a feature.
The following code lists the schema definition for link types:
<?xml version="1.0" encoding="utf-8"?> <xs:schema id="WorkItemLinkTypeDefinition" elementFormDefault="unqualified" attributeFormDefault="unqualified" xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://schemas.microsoft.com/VisualStudio/2005/workitemtracking/WorkItemLinkTypeDefinition.xsd" xmlns="http://schemas.microsoft.com/VisualStudio/2005/workitemtracking/WorkItemLinkTypeDefinition.xsd" xmlns:mstns="http://schemas.microsoft.com/VisualStudio/2005/workitemtracking/WorkItemLinkTypeDefinition.xsd" xmlns:typelib="http://schemas.microsoft.com/VisualStudio/2005/workitemtracking/typelib" version="1.0"> <xs:import namespace="http://schemas.microsoft.com/VisualStudio/2005/workitemtracking/typelib"/> <xs:simpleType name="TopologyTypes"> <xs:restriction base="xs:string"> <xs:enumeration value="Network" /> <xs:enumeration value="DirectedNetwork" /> <xs:enumeration value="Dependency" /> <xs:enumeration value="Tree" /> </xs:restriction> </xs:simpleType> <xs:complexType name="LinkTypeType"> <xs:attribute name="ReferenceName" type="typelib:ReferenceName" use="required" /> <xs:attribute name="Topology" type="TopologyTypes" use="optional" /> <xs:attribute name="ForwardName" type="typelib:FriendlyName" use="optional" /> <xs:attribute name="ReverseName" type="typelib:FriendlyName" use="optional" /> </xs:complexType> <xs:complexType name="LinkTypesType"> <xs:sequence> <xs:element name="LinkType" type="LinkTypeType" minOccurs="1" maxOccurs="unbounded" /> </xs:sequence> </xs:complexType> <xs:element name="LinkTypes" type="LinkTypesType" /> </xs:schema>