Create a Node.js module to expose OData services

Create a Node.js module. Right-click on your project and select New->Node.js Module:

Call it js:

Add a description, check the XSJS support box and click on Finish

You will now create an OData file to expose the contents of the artifacts you defined in your CDS module. This is not really Node.js development but the utilization of the runtime environment to expose OData. You can see real examples of Node.js development in the SHINE model later.

Create a file called xsodata/PO.xsodata under js->lib

Open the file called PO.xsodata and add the following content:

service {
	"PO.PO_VIEW" as "POHeader"
	keys ("PURCHASEORDERID")
	navigates ("Items" as "POItem");

	"PO.ITEM" as "POItem";
	association "Items" principal "POHeader"("PURCHASEORDERID")
	multiplicity "1" dependent  "POItem"("PURCHASEORDERID") multiplicity "*";

}

Note: You can disregard the warning in the OData definition

Save and Build the js module.

You have a database module and now you also have a Node.js module. These modules could technically be executed separately, even deployed separately. However, the Node.js module needs data from the database module. You need to add this dependency in the file that keeps them all together, the mta.yaml.

Double-click on the file to open it:

Make sure you are on the MTA Editor and on the js module:

Add both the HDI container and database modules to the Requires section of the js modules.

Save the MTA file.

Run the js module by right-clicking on the folder and selecting Run as Node.js application

Note: This may take a couple of minutes as the module will be built first.

Click on the URL to open a new tab:

Edit the URL to access the OData service, replace index.xsjs with /xsodata/PO.xsodata:

Add ?$format=json to the end of the URL. Use the results to answer the question below.