CORS anywhere proxy (Cross-Origin Resource Sharing)
This article describes steps enable a SAPUI5 app to use CORS (cross origin resource sharing).
CORS happens, when a web application contacts resources from different servers. This will be prevented by default.
With SAP Business Application Studio (BAS) and Business Technology Platform (BTP) generally this can be circumvented by three approaches:
- Deactivate CORS policy in the browser
- Create Destination in SAP BTP
- Implement local CORS proxy, i.e. node.js based cors-anywhere https://www.npmjs.com/package/cors-anywhere
The last approach is demonstrated in this article.
I have implemented two sample applications with CORS implementation:
OpenUI5 Basic Local App
See: https://github.com/mattxdev/openui5-basic-local-app/
Explanations to CORS implementation: [SAPUI5_Local_Development_and_Deployment]
OpenUI5 Walkthrough
https://sdk.openui5.org/topic/3da5f4be63264db99f2e5b04c5e853db
In Step 25 of the walkthrough a remote OData service will be used: https://sdk.openui5.org/topic/44062441f3bd4c67a4f665ae362d1109
The CORS policy in Google Chrome prevents this to work.
Therefore I have tried to implement the same solution as in the OpenUI5 Basic Local App above, but I could not get it to work in SAP BAS on the SAP BTP Trial:
https://github.com/matt-wombat/openui5-walkthrough
Downloading this to a local machine is untested yet.
