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Starting a Process via Task Resources

DSF-Team5/27/24About 2 min

Starting a Process via Task Resources

To start a BPMN process, you need to create new a Task resource in the DSF FHIR server by sending an HTTP request according to the FHIR RESTful API. Specifically, you need to create
a resource for the first time. Also, remember that the Task resource you are sending needs to comply to the Task profile of the process you want to start and the ActivityDefinition's authorization rules.
There are two major ways of making this HTTP request:

  1. Using cURL
  2. Using the DSF FHIR server's web interface

Using cURL

In order to use cURL, you will have to create an appropriate Task resource to post to the DSF FHIR server. There already is a file called example-task.xml located in tutorial-process/src/main/resources/fhir. You can use this as your starting point. You can try to follow this guide, or you can check the solution branches for this file if you need ideas on how to fill it out properly.

Below are some cURL command skeletons. Replace all <>-Placeholders with appropriate values. Host name depends on the instance you want to address.

Linux:
curl https://<instance-host-name>/fhir/Task \
--cacert <path/to/ca-certificate-file.pem> \
--cert <path/to/client-certificate-file.pem>:password \
--key <path/to/client-private-key-file.pem> \
-H "Content-Type: application/fhir+xml" \
-H "Accept: application/fhir+xml" \
-d @<path/to/example-task.xml>
Windows CMD:
curl https://<instance-host-name>/fhir/Task ^
--cacert <path/to/ca-certificate-file.pem> ^
--cert <path/to/client-certificate-file.pem>:password ^
--key <path/to/client-private-key-file.pem> ^
-H "Content-Type: application/fhir+xml" ^
-H "Accept: application/fhir+xml" ^
-d @<path/to/example-task.xml>

This may throw an error depending on which version of cURL Windows is using. If this is the case for you after making sure you entered everything correctly, you can try using Git's version of cURL instead by adding it to the very top of your system's PATH environment variable. Git's cURL is usually situated in C:\Program Files\Git\mingw64\bin.

Using the DSF FHIR Server's Web Interface

When visiting the web interface of a DSF FHIR server instance (e.g. https://instance-name/fhir), you can query the DSF FHIR server using the FHIR RESTful API to return a list of all Draft Task Resources. These Task resources act like a template you can use to instantiate Task resources which start BPMN processes. Instead of querying the DSF FHIR server manually, you can use a predefined bookmark to navigate to the query URL. You can find a list of Bookmarks in the top right corner of the web interface. Simply select the bookmark referencing ?_sort=_profile,identifier&status=draft under the Task section, and you will be taken to the list of all Draft Task Resources. Once there, you can select the one which starts your BPMN process. It will take you to a detailed view of the resource where you will also have the chance to fill any Task Input Parameters you might need to specify. If everything is filled out correctly, you may start your process by clicking Start Process. Keep in mind that, for Draft Task Resources to be available, you need to include them in your mapping for your BPMN process ID in ProcessPluginDefinition#getFhirResourcesByProcessId. Take a look at the Process Plugin Definition if you need a reminder.

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