In this post, you will learn how to create Pipeline Templates in Service Bus 12c.
A Pipeline Template defines general shape or pattern of your message flow. We use Service Bus project XYZCustomer shown below for the demonstration purpose and we intended to create proxy service performing CRUD operations on objects like Customer.
Note: You can create new folders by navigating to File -> New -> From Gallery -> General -> Folder.
Right click Pipelines folder and select New -> Pipeline Template.
Give a meaningful name. Here we are using name CustomerPipelineTemplate.
Click Next. In this screen, you can choose service type depending on your requirement. Here we want to create WSDL based proxy service, so choose Service Type as WSDL SOAP as shown below.
Click Finish and verify that new Pipeline Template is created and opened in a separate tab as shown below.
Pipeline templates are the right candidates to keep common logic or enforce pattern of message flow to be followed across Proxy services. Typically, you may want to perform following common activities for different operations that your Proxy Service supports.
- Validation of payload against schema
- Routing to a business service (e.g: CustomerServiceBS)
- Error Handling
Along with above functionality, your Pipeline Template needs to have nodes like Operational branch, Pipeline Pair, Stages etc…
When consumers call Proxy Service, it has to take different execution paths based on operation called. The Service Bus provides Operational Branch node serving this purpose. So drag Operational from Template Placeholders onto pipeline template where yellow circle is shown.
Note: All Nodes or activities used in message flow for Pipeline or Pipeline template are available in Components -> Message Flow under different sections. If you don’t see Components window, get it by selecting Window -> Components.
Click BranchNode1 and set name as CustomerOperation in Properties tab as shown below. As a best practice, always give meaningful labels for Nodes and other activities (wherever applicable).
Now drag Pipeline Pair from Nodes into Branch and give name as PipelinePair and rename Stage1 node in Request Pipeline to Validation in Properties tab. Now your pipeline template should look like below.
Service Bus provides Validate activity to do payload validation against schema. So drag Validate activity into Validation stage from Message Processing.
In Properties tab, set Location property value as body and other properties as shown below. Here you will not select any schema or WSDL for validate activity as it’s just template and we will not have any payload available.
There may be additional validations to be performed while designing message flow in concrete Pipelines which requires a place holder. So drag Actions into Validation stage as shown below from Template Placeholders.
Delete Stage1 in Response Pipeline by selecting Delete option on right click. Also you may need to create several Stage nodes in your concrete Pipeline’s message flow. So create a place holder for the same in your template. Drag Stages into pipeline after Validation stage and in Response Pipeline from Template Placeholders. Now your pipeline pair node should look like below.
Routing node always depicts end of your message flow and you will not be able to place any other activities after this node. So drag and place Route after PipelinePair from Template Placeholders and set name as Route in Properties tab. Observe Actions placeholder which allows user to place any type of activity while designing message flow for your concrete pipelines.
Error handling is another aspect of message flow where you may want to follow similar approach for all Proxy Services. So drag Error Handler onto CustomerPipelineTemplate from Nodes. And in Properties tab, set name as ErrorHandler for Stage1 as shown below.
We will see Error Handling in detail in separate post. For the time being, you can drag Actions placeholder into ErrorHandler stage.
With this, you are done with Pipeline Template and can proceed with creation of Pipelines using this template.
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