/// <summary>
/// Makes a request to the Salesforce client, wrapping the specified logic with the code necessary to handle authentication.
/// </summary>
/// <typeparam name="T">The type of value returned from the request.</typeparam>
/// <param name="request">The request to make on the Salesforce client.</param>
/// <exception cref="InvalidOperationException">The current user is not authenticated.</exception>
/// <returns>The value returned by the request.</returns>
public static async Task <T> MakeAuthenticatedClientRequestAsync <T>(Func <ForceClient, Task <T> > request)
{
bool done = false;
bool refreshedToken = false;
T result = default(T);
do
{
// 1. Get the token from the cache
SalesforceToken salesforceToken = HttpContext.Current.Session[SalesforceService.TokenCacheKey] as SalesforceToken;
// 2. If no token is available, redirect to authorize
if (salesforceToken == null)
{
// This exception message should be used to trigger the sign-in UI
throw new InvalidOperationException("AuthorizationRequired");
}
// Initialize the ForceClient
ForceClient forceClient = salesforceToken.GetForceClient();
try
{
// 3. Invoke the request with the acquired token
result = await request(forceClient);
done = true;
}
catch (ForceException e)
{
// If message is "Session expired or invalid", the access token is invalid, so eat the
// exception and fall through to try to update it using the refresh token.
if (e.Message != "Session expired or invalid")
{
throw;
}
if (refreshedToken)
{
// The access token is invalid and was already refreshed once, give up and
// re-throw the exception.
throw;
}
}
// 4. If the token is invalid, attempt to acquire a new access token from the refresh token
if (!done)
{
await SalesforceService.AcquireAccessTokenFromRefreshTokenAsync(salesforceToken);
refreshedToken = true;
}
} while (!done);
return(result);
}
