What

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Is a Pipeline

A pipeline is an ordered collection of tasks executed in sequence. This can be used to chain together tasks that are executed in order, e.g. call a service, transform its output from XML to JSON and return the response.

For more information on configuring pipelines for the Gateway see these pages Config - Pipelines.

What

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Is a Task

A task is an action performed within a pipeline - many different tasks existsexist, ranging from branches (if...then...else) task, to validations, convertionsconversions, logging, tracing to service callouts, proxying requests or returning responses.

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Example flow of tasks within a pipeline.

In this example, we have a pipeline with a number of tasks, first we call a service, then update the value of a request attribute with the content of the HTTP response headers, after this, we transfer from JSON to XML, and then in case of failure we send a failure response, otherwise we update the JSON content by running a script (here, we add the XML as an attribute in the response) which we then send in the final task.

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Here is a screenshot of how these tasks are edited in the Ceptor Console. You can reorder tasks by dragging them around in the list, and right-click them to add/remove more. You can also drag new tasks into the pipeline from the Task Palette.

Are

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Tasks Always Needed?

No, tasks are not always needed - you might be able to perform similar custom actions in an authentication or authorization script within the gateway, but tasks are often a more elegant and more readable way of archiving results.
Also, while a script needs to block waiting for external events to complete, a task can be asynchronous, so some operations especially those that do IO work will perform better when split into async tasks.

List of

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Tasks

The following tasks are currently available:

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• If...then...else
  Allows you to branch out, based upon a list of configured conditions - if conditions match, one branch of tasks are executed, if not - another branch is executed instead.
• If failure then... else
  If any of the previous tasks has have failed with an error (unless the error has been cleared) then execute X tasks, if not, execute Y other tasks.

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• Base64 encode/decode
  Base64 encode or decode any value - result is stored in a request attribute.
• URL encode/decode
  Allows you to URL encode/decode any value, variable or macro - result is stored in a request attribute.
• HTML encode
  Allows you to HTML encode a text - escapes any HTML characters ensuring the result is safe to display in a web page.
• Transform JSON to XML
  Transforms JSON into XML tags.
• Transform XML to JSON
  Transforms XML into JSON, note that some information will be lost in transit, such as attributes, order and namespaces.
• Transform JSONML to XML
  Transforms from JSON Markup Language into XML - see http://www.jsonml.org/ for information on JSON ML.
• Transform XML to JSONML
  Transform from XML into JSON Markup Language - this transformation can be reverted back into JSON without loss of data, but note that the format is quite verbose and may take up a lot of memory space.

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• Write to Trace
  If request trace is enabled within the gateway, this writes a value to it.
• Write to Log
  Writes a value to the log at the given log level - logger name can also be specified.
• Write to Transaction Log
  Allows you to write a message to the transaction log - this log resides at the Ceptor Session Controller - implemented by individual authentication plugins so writing here is a remote call.

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