Handlers & Pipelines Adding a pipeline

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Questions and Answers

What is a key requirement for a pipe to be included in a pipeline?

Must specify a priority using the 'Priority' property

Must return multiple results from the 'Execute' method

Must implement the IHandler interface

Must implement the IPipe interface (correct)

What property do pipes use to determine the execution order within a pipeline?

Order (correct)

Ranking

Position

Sequence

In which scenario will the execution of a pipeline halt?

When the pipeline has no pipes left to execute

When an error code is returned by a pipe (correct)

When all pipes have completed their execution

When the first pipe completes successfully

How are the default order values of pipes typically structured in a pipeline?

Incremented by 100 starting from 100 Signup and view all the answers

What aspect distinguishes pipelines from handler chains?

Pipelines can be executed anywhere logic is needed Signup and view all the answers

Which pipeline is responsible for creating ProductDto objects?

CreateProductDtos Signup and view all the answers

What happens if a pipe does not return a result in the 'Execute' method?

The entire pipeline fails to execute Signup and view all the answers

What was a primary motivation for introducing pipelines instead of using handler helpers?

To allow easier modification without breaking backward compatibility Signup and view all the answers

What order value should you assign to a new pipe if you want it to be inserted in the second position of a pipeline?

Between 101 and 199 Signup and view all the answers

How are pipes associated with a pipeline?

Through the parameter and result object types Signup and view all the answers

What happens when you add a pipe with an order value of less than 100 to a pipeline?

The pipe is inserted at the start of the pipeline Signup and view all the answers

What should you specify for the TIn and TOut parameter and result object types in a new pipe class?

Those specifically defined for the pipeline Signup and view all the answers

What is the default order value of the first pipe in a pipeline?

100 Signup and view all the answers

If a new pipe is added with an order value of 3000, what does that imply for its position in the pipeline?

The pipe will be executed last in the pipeline Signup and view all the answers

Which class is part of the same pipeline due to sharing the same parameter and result object types?

CalculateOrderTotal Signup and view all the answers

What consequence follows if you do not specify the correct parameter and result object types when implementing a new pipe?

The new pipe will not be able to process data Signup and view all the answers

What condition must be fulfilled for the pipeline to continue executing without errors?

The customer in the parameter must not be null. Signup and view all the answers

What happens if the ResultCode is set to ResultCode.Error?

The pipeline will exit immediately. Signup and view all the answers

Which property should be set to true to exit the pipeline without indicating an error?

result.ExitPipeline Signup and view all the answers

Which message is returned if the customer parameter is null?

A customer is required to format the label. Signup and view all the answers

What is the purpose of the 'Execute' method in the pipe?

To perform the main operation of the pipeline. Signup and view all the answers

What does setting 'result.ExitPipeline' to true do?

It terminates pipeline processing immediately. Signup and view all the answers

What is used to append the customer's postal code to the result label?

result.Label += parameter.Customer.PostalCode Signup and view all the answers

Which aspect of the result is updated when the pipeline encounters a valid customer?

Label Signup and view all the answers

What happens if the 'ExitPipeline' flag is set to true?

Execution of the pipeline stops immediately. Signup and view all the answers

Which of the following statements about replacing a pipe is true?

The new pipe's order value must match the pipe being replaced. Signup and view all the answers

What must a new pipe do to function as a replacement in the pipeline?

Return a result from the 'Execute' method. Signup and view all the answers

When is the customer label updated to include the postal code?

Automatically when the postal code is not empty. Signup and view all the answers

What is one of the requirements for a new pipe to replace an existing one?

It must have the same name as the pipe being replaced. Signup and view all the answers

What might indicate an error in processing a customer's label?

The message 'A customer is required to format the label.' is added. Signup and view all the answers

What is the first step after successful configuration of a new pipe replacement?

Test the pipeline to ensure the new pipe functions correctly. Signup and view all the answers

What occurs in the pipeline after returning a result without setting the ExitPipeline property?

Control is handed over to the subsequent pipe. Signup and view all the answers

Study Notes

Pipelines

Pipelines are reusable portions of business logic that are not transactional.
Pipelines are similar to handler chains and are made up of one or more classes called pipes.
Pipes must implement the IPipe interface, return a result from the Execute method and specify an order using the Order property.
Pipelines can be executed wherever the logic is needed.
Individual pipes can choose to halt execution of the rest of the pipeline by returning an error code or exiting the pipeline.
Pipes within a pipeline are executed in order.

Adding a pipe

To associate a pipe with a specific pipeline, the TIn and TOut parameters must match the parameter and result object types of the pipeline.

Example of adding a pipe

In this example, a new pipe called AddCustomerZipCode is added to the FormatLabel pipeline to add the customer's zip code to the label.
The AddCustomerZipCode pipe implements the IPipe interface with the FormatLabelParameter and FormatLabelResult object types.
The Order property is set to 3000 to ensure the new pipe executes after the existing pipes in the FormatLabel pipeline.
The Execute method checks if the customer has a postal code and appends it to the label if it does.

Replacing a pipe

To replace an existing pipe, the new pipe must implement the IPipe interface, return a result from the Execute method, specify an order using the Order property, and be named the same as the pipe being replaced.
The new pipe must use the same TIn and TOut types as the pipe being replaced.

Example of replacing a pipe

The example in the text replaces the FormatLabel pipe with a new one that has the same name.

Best practice

When replacing a pipe, it is best practice to match the order value of the original pipe.

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Description

Explore the concepts of pipelines and pipes in business logic. This quiz covers the implementation of the IPipe interface, execution order, and handling of results. Test your knowledge with practical examples and scenarios involving the addition of pipes to pipelines.