Question Re: CAPM: undefined is not iterable in Technology Q&A

CAPM: undefined is not iterable

EkanshCapgemini — Sun, 04 Feb 2024 02:26:51 GMT

Hi,

I am following the learning journey 'Developing with SAP Extension Suite' from SAP BTP Learning Group. I am consuming Business Partner service from S4HANA Cloud via API Gateway sandbox. According to the learning journey, I am implementing my own service handler to handle $expand case when it calls data from business partners. However, I am getting error in cds watch logs that 'TypeError: undefined is not iterable (cannot read property Symbol(Symbol.iterator))'.

Here is my code

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

// service implementation with handlers
module.exports = cds.service.impl(async function () {
  const { Risks, BusinessPartners } = this.entities;

  // connect to remote service
  const BPSrv = await cds.connect.to("API_BUSINESS_PARTNER");

  // to handle $expand=bp call
  this.on("READ", Risks, async (req, next) => {
    try {
      const res = await next();
      if (Array.isArray(res)) {
        const aColumns = req.query.SELECT.columns || [];
        const aBpColumn = aColumns.find((column) => column.ref.includes("bp"));
        if (aBpColumn.expand && aBpColumn.expand.length > 0) {
          // $expand=bp was used
          const aRiskBps = res.map((risk) => risk.bp_BusinessPartner);
          const aBps = await BPSrv.run({
            query: SELECT.from(BusinessPartners)
              .where({ BusinessPartner: { in: aRiskBps } })
              .columns(["BusinessPartner", "FirstName", "LastName"]),
            headers: {
              apiKey: process.env.apiKey,
            },
          });
          console.log(aBps);
        }
      }
    } catch (error) {
      console.error(error);
    }
  });
});

Re: CAPM: undefined is not iterable

chgeo — Tue, 23 Nov 2021 12:25:34 GMT

Please add the full error, incl. stack trace. If that is not visible, set DEBUG=true and start again.

Re: CAPM: undefined is not iterable

EkanshCapgemini — Tue, 23 Nov 2021 12:35:37 GMT

Hi christian.georgi, I updated the error with stack trace in the question.

Re: CAPM: undefined is not iterable

chgeo — Tue, 23 Nov 2021 12:57:49 GMT

Don't see it.. it's an empty box

Re: CAPM: undefined is not iterable

EkanshCapgemini — Tue, 23 Nov 2021 13:04:32 GMT

[cds] - > READ Risks {
  '$count': 'true',
  '$select': 'HasActiveEntity,ID,IsActiveEntity,bp_BusinessPartner,criticality,descr,impact,miti_ID,owner,prio,title',
  '$filter': '(IsActiveEntity eq false or SiblingEntity/IsActiveEntity eq null)',
  '$expand': 'bp($select=BusinessPartner,LastName),miti($select=ID,IsActiveEntity,description)',
  '$skip': '0',
  '$top': '30'
}
TypeError: undefined is not iterable (cannot read property Symbol(Symbol.iterator))
    at _newQuery (/home/user/projects/risk-management/node_modules/@sap/cds/libx/_runtime/common/utils/resolveView.js:591:26)
    at resolveView (/home/user/projects/risk-management/node_modules/@sap/cds/libx/_runtime/common/utils/resolveView.js:616:20)
    at RemoteService.handle (/home/user/projects/risk-management/node_modules/@sap/cds/libx/_runtime/remote/Service.js:207:17)
    at RemoteService.dispatch (/home/user/projects/risk-management/node_modules/@sap/cds/lib/serve/Service-dispatch.js:47:15)
    at RemoteService.dispatch (/home/user/projects/risk-management/node_modules/@sap/cds/lib/serve/Service-dispatch.js:17:48)
    at RemoteService.run (/home/user/projects/risk-management/node_modules/@sap/cds/lib/serve/Service-api.js:51:17)
    at ApplicationService.<anonymous> (/home/user/projects/risk-management/srv/risk-service.js:29:36)
    at async next (/home/user/projects/risk-management/node_modules/@sap/cds/lib/serve/Service-dispatch.js:81:17)
    at async ApplicationService.handle (/home/user/projects/risk-management/node_modules/@sap/cds/lib/serve/Service-dispatch.js:79:10)
    at async _readCollection (/home/user/projects/risk-management/node_modules/@sap/cds/libx/_runtime/cds-services/adapter/odata-v4/handlers/read.js:259:19)

I don't know why but the trace is getting replaced with <br/> tag in code block in question. So I am trying to paste it in comments now. christian.georgi

Re: CAPM: undefined is not iterable

chgeo — Tue, 23 Nov 2021 13:35:58 GMT

johannesvogel can you check this one?

Re: CAPM: undefined is not iterable

johannesvogel — Tue, 23 Nov 2021 14:09:38 GMT

Hi ekansh005 ,

"BPSrv.run" is not designed to provide custom headers for a request to a remote service.

Did you see that snippet in the learning journey or in one of our samples?

Please either use .send in order to send custom headers with the request or consider adding the apiKey as a declarative header to the app defined destination.

Hope that helps,

Johannes

Re: CAPM: undefined is not iterable

EkanshCapgemini — Tue, 23 Nov 2021 14:33:53 GMT

Ahh... I misread .send as .run and was banging my head 🙂

Thanks for your explanation and it works as expected on changing it to .send().

BR, Ekansh