Consuming Microsoft 365 API in the Cloud Application Programming (CAP) Model

The SAP Devtoberfest 2020 challenge brought new insights to simplify the consuming external API in NodeJS and the Cloud Application Programming (CAP) Model and combine them with a concept for integrating Microsoft Azure and Google Cloud APIs.

As a result of this challenge, the SAP mentor’s community announced a new node.js library CDS-SCP-API for simplifying the consuming external service in Cloud Application Programming (CAP) Model. This blog will explain how you can use this node.js library for consuming Microsoft 365 APIs.

We will use the Microsoft Graph API for reading all users’ full profiles, which API documentation can be found at Microsoft Graph REST API v1.0 documentation. But you can use any API which is available at Microsoft Azure.

To use Microsoft 365 APIs, we first need to configure the Microsoft Graph API layer in Microsoft Azure. These 19 configuration steps in Microsoft Azure are written here in the documentation of the node.js library CDS-SCP-API.

After we have configured Microsoft Azure, we need to configure our destination in the SAP Cloud Platform Destination Service.

URL               : https://graph.microsoft.com
Client ID         : <Application client ID of Azure App>
Client Secret     : <Clients Secrets Value of Azure App>
Token Service URL : https://login.microsoftonline.com/<Directory Tenant ID of Azure App>/oauth2/v2.0/token
                    or <Token Service URL : <Application OAuth 2.0 token Endpoint(v2) of Azure App>
Scope             : https://graph.microsoft.com/.default

Now we set up SAP Cloud Platform and Microsoft Azure, we are ready to build our CAP project.

1. Create a new folder and enter the new folder

   mkdir <cds-azure-example-folder>
   cd <cds-azure-example-folder>​

2. Initialize as CAP CDS project

   cds init​

3. Add cds-scp-API dependencies in the package.json file.

   "dependencies": {
     ...
     "@sapmentors/cds-scp-api": "latest"
   },​

4. install the node packages by running

   npm install​

5. add a file named msgraph-user-service.cds with the following cds definition in the srv folder

   @impl:'msgraph-user-service.js'
   @cds.query.limit: 100
   service MSGraphService @(requires:'any'){
     @cds.persistence.skip
     entity User {
       key aad_id                 : String;
           username               : String;
           displayName            : String;
           givenName              : String;
           surname                : String;
           isAzureActiveDirectory : Boolean;
     }
   }​

6. add a file named msgraph-user-service.js with the following cds definition in the srv folder

   const cdsapi = require("@sapmentors/cds-scp-api");
   
   const readFunction = async (req) => {
     let destination = 'MSGraph'
     const url = `/v1.0/users/`
     const service = await cdsapi.connect.to(destination);
     const graphUser = await service.run({
       url: url
     })
   
     let users = graphUser.value.map(graph_user => {
       var user = {}
       user.aad_id = graph_user.id
       user.username = graph_user.userPrincipalName
       user.displayName = graph_user.displayName
       user.givenName = graph_user.givenName
       user.surname = graph_user.surname
       user.isAzureActiveDirectory = true
       return user
     })
     return users
   }
   
   module.exports = (srv) => {
     srv.on('READ', 'User', readFunction)
   }​

7. create a default-env.json file as described in the prerequisites for running examples locally
8. Start CDS watch to start the application.

   cds watch​

9. Open http://localhost:4004 in your browser to open an overview of the CAP services.
   
10. Click on the link User to see the data from Microsoft Azure Active Directory User List API.