Tutorial: Call Microsoft Graph API from a Node/Express.js web app

In this tutorial, you call Microsoft Graph API from a Node/Express.js web app. Once a user signs in, the app acquires an access token to call Microsoft Graph API.

This tutorial is part 3 of the 3-part tutorial series.

In this tutorial, you:

• Complete the steps in Tutorial: Add add sign-in to a Node/Express.js web app by using Microsoft identity platform.

1. In your code editor, open views/index.hbs file, then add an View user profile link by using the following code snippet:

   <a href="/users/profile">View user profile</a>
   

   After you make the update, your views/index.hbs file should look similar to the following file:

      <h1>{{title}}</h1>
       {{#if isAuthenticated }}
       <p>Hi {{username}}!</p>
       <a href="/users/id">View ID token claims</a>
       <br>
       <a href="/users/profile">View user profile</a>
       <br>
       <br>
       <a href="/auth/signout">Sign out</a>
       {{else}}
       <p>Welcome to {{title}}</p>
       <a href="/auth/signin">Sign in</a>
       {{/if}}
   

2. Create views/profile.hbs file, then add the following code:

   <h1>Microsoft Graph API</h1>
   <h3>/me endpoint response</h3>
   <table>
       <tbody>
           {{#each profile}}
           <tr>
               <td>{{@key}}</td>
               <td>{{this}}</td>
           </tr>
           {{/each}}
       </tbody>
   </table>
   <br>
   <a href="/">Go back</a>
   

   • This page displays the user's profile details that Microsoft Graph API returns.

In your code editor, open the auth/AuthProvider.js file, then add getToken method in the AuthProvider class:

class AuthProvider {
    //...
        getToken(scopes, redirectUri = "http://localhost:3000/") {
            return  async function (req, res, next) {
                const msalInstance = authProvider.getMsalInstance(authProvider.config.msalConfig);
                try {
                    msalInstance.getTokenCache().deserialize(req.session.tokenCache);
    
                    const silentRequest = {
                        account: req.session.account,
                        scopes: scopes,
                    };
                    const tokenResponse = await msalInstance.acquireTokenSilent(silentRequest);
    
                    req.session.tokenCache = msalInstance.getTokenCache().serialize();
                    req.session.accessToken = tokenResponse.accessToken;
                    next();
                } catch (error) {
                    if (error instanceof msal.InteractionRequiredAuthError) {
                        req.session.csrfToken = authProvider.cryptoProvider.createNewGuid();
    
                        const state = authProvider.cryptoProvider.base64Encode(
                            JSON.stringify({
                                redirectTo: redirectUri,
                                csrfToken: req.session.csrfToken,
                            })
                        );
                        
                        const authCodeUrlRequestParams = {
                            state: state,
                            scopes: scopes,
                        };
    
                        const authCodeRequestParams = {
                            state: state,
                            scopes: scopes,
                        };
    
                        authProvider.redirectToAuthCodeUrl(
                            req,
                            res,
                            next,
                            authCodeUrlRequestParams,
                            authCodeRequestParams,
                            msalInstance
                        );
                    }
    
                    next(error);
                }
            };
        }
}
    //...

The getToken method uses the specified scope to acquire an access token

In your code editor, open the routes/users.js file, then add the following route:

router.get(
    "/profile",
    isAuthenticated,
    authProvider.getToken(["User.Read"]), // check if user is authenticated
    async function (req, res, next) {
    const graphResponse = await fetch(
        GRAPH_ME_ENDPOINT,
        req.session.accessToken,
    );
    if (!graphResponse.id) {
        return res 
        .status(501) 
        .send("Failed to fetch profile details"); 
    }
    res.render("profile", {
        profile: graphResponse,
    });
    },
);

• You trigger the /profile route when the customer user selects the View user profile link. The app:

  • Acquires an access token with the User.Read permission.
  • Makes a call to Microsoft Graph API to read the signed-in user's profile.
  • Displays the user details in the profile.hbs UI.

Create fetch.js file, then add the following code:

var axios = require('axios');
var authProvider = require("./auth/AuthProvider");

/**
 * Makes an Authorization "Bearer" request with the given accessToken to the given endpoint.
 * @param endpoint
 * @param accessToken
 * @param method
 */
const fetch = async (endpoint, accessToken, method = "GET", data = null) => {
    const options = {
        headers: {
            Authorization: `Bearer ${accessToken}`,
        },
    };

    console.log(`request made to ${endpoint} at: ` + new Date().toString());

    try{
        const response = await axios.get(endpoint, options);
        return await response.data;

    }catch(error){
        throw new Error(error);
    }

};

module.exports = { fetch };

The actual API call happens in the fetch.js file.

1. Use the steps in Run and test the Node/Express.js web app to run your web app.
2. Once you sign in, select View user profile link. If your app works correctly, you should see the signed-in user's profile as read from Microsoft Graph API.