How to convert an MS Graph API call to GraphServiceClient method call? - asp.net-core

Question

What is the GraphServiceClient version of querying another user's calendar?
var cal = await _graphServiceClient.???? (see code below)
Startup code
builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddMicrosoftIdentityWebApi(builder.Configuration.GetSection("AzureAd"))
.EnableTokenAcquisitionToCallDownstreamApi()
.AddInMemoryTokenCaches();
var app = builder.Build();
Razor pages code
using Microsoft.Graph;
using Microsoft.Identity.Web;
namespace MSGraphAPIPOC.Pages;
[Authorize]
[AuthorizeForScopes(Scopes = new[] { "Calendars.ReadWrite" })]
public class IndexModel : PageModel
{
private readonly ILogger<IndexModel> _logger;
private readonly GraphServiceClient _graphServiceClient;
public IndexModel(ILogger<IndexModel> logger, GraphServiceClient graphServiceClient)
{
_logger = logger;
_graphServiceClient = graphServiceClient;
}
public async Task OnGet()
{
...
https://graph.microsoft.com/v1.0/users/<calendarSMTP>/calendarview?startDateTime=2022-07-05T00:00:00&endDateTime=2022-07-05T23:59:00&select=start,end,subject
var cal = await _graphServiceClient.???? //What is the equivalent of the api call above?
...
}
}
Any help would be appreciated.

Answer 1

There are 2 types of ms graph api permission, one is delegate which means users can sign in first and then query their own information via ms graph api. Another type is Application, this means application can query all users' information via graph api.
Come back to your scenario, you integrate azure ad into your asp.net core web application, which means users have to sign in first before then visit Index page right? So you are now using the delegate api permission, which allowing you to use await _graphServiceClient.Me.CalendarView.Request( queryOptions ).GetAsync() to query his/her own calendar view but don't have permission to query others.
If you want to query others, you have to consent application api permission. In your scenario, the api supports application permission. Then following the screenshot in this section to add the permission. Then using code below or this sample section to call the api:
using Azure.Identity;
using Microsoft.Graph;
var scopes = new[] { "https://graph.microsoft.com/.default" };
var tenantId = "your_tenant_name.onmicrosoft.com";
var clientId = "azure_ad_app_id";
var clientSecret = "client_secret";
var clientSecretCredential = new ClientSecretCredential(
tenantId, clientId, clientSecret);
var graphClient = new GraphServiceClient(clientSecretCredential, scopes);
var queryOptions = new List<QueryOption>()
{
new QueryOption("startDateTime", "2022-07-05T00:00:00"),
new QueryOption("endDateTime", "2022-07-05T23:59:00")
};
var res = await graphClient.Users["user_id"].CalendarView.Request(queryOptions).Select("start,end,subject").GetAsync();