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Connect-REST method

 

Use the Connect-REST method to start an HTTP request/response interaction between the Pega Platform and the external system identified by a Connect REST rule (Rule-Connect-REST rule type).

Parameters

This method accepts three required and one optional parameter.

Parameter

Description

ServiceName

Service name of the Connect REST rule to run.

EndPointURL

Optional. Specify the URL of an external system to which you want to connect. A value specified for this parameter overrides the value set in the End Point URL field on the Service tab of the Connect REST rule.

MethodName

HTTP method to execute. Select GET, POST, PUT or DELETE.

ExecutionMode

Select to indicate the timing of execution

  • Run — Execute the connector synchronously; the next step of the activity containing the Connect-REST method does not execute until the connector response is received. (This is the default.)
  • Run in Parallel — This connector is to run in parallel as a child requestor of the current requestor. If selected, use the Connect-Wait method later in the current or a follow-on activity to access results from the connector. By default, an invoked connector retains control of the requestor session until it returns a response. Select this parameter if you want the connector to return control of the session directly after completing the request without waiting for a response. If a subsequent connector in the flow has a shape to accomplish, that connector can send its request before the first connector returns a response.
  • Queue — Add this connector request to a queue, defined by a Connect Request Processor data instance, for background processing by the Pega-IntSvcs ProcessConnectQueue agent. This mode works only if the Request Processor field on the Service tab of the Connect REST rule identifies a Data-Admin-RequestProcessor-Connect data instance. When the agent executes a queued connector request, the execution is performed with the authorization profile of the original requestor.

Results

The Connect-REST method works as follows:

  1. Using rule resolution, locates the Connect REST rule identified by the ServiceName parameter and the class of the step page or primary page.
  2. Uses the HTTP method identified by the MethodName parameter to assemble a HTTP request message.
  3. If the step page does not exist, creates a new page, of the class identified in the Pages & Classes tab.
  4. Checks whether simulation is in force for this rule. If true, results depend on the Execution mode value:
  1. If simulation is not in force, calls the Web service, or queues the request, depending on the Execution mode value:
  2. Processes the response message when it is received. (No response is available for queued connector requests.)

Checking the method status

This method updates the pxMethodStatus property. See How to test method results using a transition.

Design the activity to detect and handle exceptions. If the Connect-REST method with the Execution Mode of Run In Parallel fails in a way that causes the Connect-Wait method to be skipped, the child requestor can be left hanging. If the limit of parallel requestors is then eventually reached, the parent requestor fails as well. By default, the limit is 10 requestors in parallel; you can establish a higher or lower value in the prconfig.xml file or Dynamic System Settings using the services/maxRequestorChildren setting.

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