Get complete tree of decisions of DMN instance from REST API

Camunda 7 Topics Discussion & Questions
3

Hi Philipp,

Thanks for taking the time to read my question and replying! The decision we are building has multiple functions. The input is a number of parameters (the values of a certain object) as filled in by the user in an application. The decision has an end outcome: ‘Are the parameters valid’. But to determine if the parameter are valid many sub decisions and calculations, like min and max values are calculated and DMN tables are evaluated. The end result (‘Are the parameters valid’) is used by the requester, but also all the intermediate results (the min and max values and DMN outputs) are needed to do stuff. Also, if the parameters are not valid, we want to tell the requester WHY the parameters are not valid. So, which parameter is invalid and what was the exact reason (‘parameter x above maximum y’ for example).

To get all input and output parameters of all underlying decisions we intend to use the following call:

http://localhost:8080/engine-rest/history/decision-instance?rootDecisionInstanceId={theRootDecisionInstanceId}&includeInputs=true&includeOutputs=true

For this would give us a basis to work from. Actually, while working on this problem I also checked Drools to see how that application handles a DMN evaluation. If I understand it correctly when you execute a Drools DMN rules tree, the complete decision tree with all inputs and outputs and all decision is returned (Drools Documentation). That actually meets our requirements completely. But we don’t really want to add another rules engine in our landscape currently.

So, to get the complete decision tree, we need at least the rootDecisionInstanceId…

Hopefully this answers your question.

Rogier