SAP CAP - Access Request Body in error handler for 400 - Bad Request error

[lorenzobigs]

Hi experts,

in a classic SAP CAP application, Node.js flavour, i have defined a service.js implementation for my service.cds , with a generic error handler:

service.js

const cds = require('@sap/cds'); 

module.exports = async function () {
  /**
  * The generic error handler
  */
  this.on('error', (err, req) => {
    //How to retrieve req.data?
    console.log('Oh no! ' + err.message);
  });
};

Let's say that I execute a POST to an entity that throws a DeserializationError. The error is being catched by the error handler but the req.data is undefined.

Is there a way in this scenario to access to the body of the request which caused the error?

[Arley · Accepted solution]

In this context, using context propagation works:

cds.context.http.req.data

[lorenzobigs · Accepted solution]

Hi @Arley , thank you, this works fine for entity served as projection of the ones in the data-model.cds.

In the scenario in which I am exposing an action with a custom defined type, the cds.context.http.req.data it is still undefined. Any suggestions?

define type EventMessage {
        ID       :      UUID;
        time     :      DateTime;
        name     :      String;
        category :      String;
        status   :      String;

    }
... 

action add @(restrict: [
        {
            grant: ['WRITE'],
            to   : 'admin'
        }])(
            ID   : EventMessage:ID,
            time : EventMessage:time,
            name : EventMessage:name,
            category : EventMessage:category,
            status : EventMessage:status
            ) returns String;