The goal: generate a draft email with body content and attachments and drop it into my current user's GMail account.
The environment: ASP.NET Core 3.1
I'm already using Google Authentication in my web app and am successfully requesting the Gmail Compose scope:
services
.AddAuthentication(options => { options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme; })
.AddCookie()
.AddGoogle(options =>
{
IConfigurationSection googleAuthSection = Configuration.GetSection("Authentication:Google");
options.ClientId = googleAuthSection["ClientId"];
options.ClientSecret = googleAuthSection["ClientSecret"];
options.Scope.Add(Google.Apis.Gmail.v1.GmailService.Scope.GmailCompose);
});
From the various samples online, this is what I've found I need to do to generate a draft and save it to a gmail account:
var draft = new Draft();
draft.Message = new Message();
draft.Message.Payload = new MessagePart { Body = new MessagePartBody { Data = "hello world".ToBase64Url() } };
var clientSecrets = new ClientSecrets
{
ClientId = _googleAuthSettings.ClientId,
ClientSecret = _googleAuthSettings.ClientSecret
};
UserCredential credential = await GoogleWebAuthorizationBroker.AuthorizeAsync(
clientSecrets,
new[] { Google.Apis.Gmail.v1.GmailService.Scope.GmailCompose },
user.Data.EmailAddress,
CancellationToken.None);
var gservice = new Google.Apis.Gmail.v1.GmailService(
new BaseClientService.Initializer
{
HttpClientInitializer = credential,
ApplicationName = "Aeon"
});
var createRequest = gservice.Users.Drafts.Create(draft, user.Data.EmailAddress);
The problem is that the call to GoogleWebAuthorizationBroker.AuthorizeAsync is a brand new auth request that pops a new browser window to auth against Google (which doesn't work because redirect urls and such). I've already authed the user through my existing startup/login process.
The two GmailService constructors take either no arguments or this BaseClientService.Initializer class, which itself takes a Google.Apis.Services.IConfigurableHttpClientInitializer object. In the sample above, the UserCredential class implements this interface. How do I use my existing login process' credentials to construct a gmail service? Alternatively, is there a way to do what I'm looking to do without having to construct a GmailService instance?
