The project that contains user-defined nodes can be exported as a plug-in that is installed in the development environment of the user. The nodes that are packaged in the plug-in are displayed in the palette in the Message Flow editor, and can be used in a message flow in the same way as a built-in node.
Packaging a subflow as a user-defined node provides all the benefits
of a subflow, such as reusability and maintainability, as well as
the following benefits:
- The user-defined node can be distributed to other developers as a plug-in.
- The user-defined node hides the implementation details of the subflow from developers who reuse the subflow.
- The user-defined node prevents developers who reuse the subflow from modifying it.
- The subflow is displayed in the palette in the Message Flow editor.
Limitations
- You cannot use user-defined nodes that are created from subflows in subflows that are defined in .subflow files.
Message flows that contain user-defined nodes that are created from subflows must be included in BAR files as compiled message flow (.cmf) files. The shared libraries that are referenced by applications that include user-defined nodes cannot be deployed together because shared libraries need to be deployed as source. For more information, see Adding files to a broker archive.
- All the flow resources (Maps, ESQL, XSL, or other external resources), except Java code and message sets, that are referenced in the subflow, must be located in the user-defined node project.
- A user-defined node can reference another user-defined node in the same or different user-defined node project, but it must not reference anything from a regular integration project.
- The user-defined node project can have references to other projects, such as message set and Java projects.
- If the user-defined node references a message set, you must deploy the message set to the runtime separately. You can copy the message set to your workspace and deploy it through the broker archive (BAR) file.
- A subflow implementation of a user-defined node can contain other subflows, but all the subflows must be contained in the user-defined node project.
- Promoted properties from the nodes within the subflow are supported. Configurable promoted properties from nodes in the subflow are displayed as configurable node properties in the Broker Archive editor.
- User-defined properties (UDP) on the subflow are supported. If you create multiple instances of user-defined nodes in your flow, each type of user-defined property that you define must have the same value in each instance.
- You can use the same subflow more than once to construct a flow of your own.
- You can use the following node types that have named correlators
to create a user-defined node, but you must not use more than one
instance of the user-defined node within a flow, an integration server,
or a broker. For example, you cannot use asynchronous request and
asynchronous response nodes, aggregate nodes, TimeoutControl and TimeoutNotification pairs of
nodes, or label nodes.
If you do use one of these node types, the resultant message flow is invalid. If you deploy flows that contain asynchronous request, asynchronous response, or label nodes, you receive an error message. However, you do not receive an error message if you deploy flows that contain TimeoutControl, TimeoutNotification, or aggregate nodes.
- Resources in the plug-in space are visible to all projects in the workspace. Keep user-defined nodes and their associated flows, maps, ESQL, and other similar resources, in appropriately named broker schemas. Do not put such resources in a default schema, or schemas with special names, for example, mqsi.
Last updated Friday, 21 July 2017