errors.md

Handling errors in the Microsoft Graph SDK for iOS

Errors in the Microsoft Graph SDK for iOS behave just like errors returned from the service.

Anytime you make a request against the service there is the potential for an error. You will see that all requests to the service can return an error. The error returned is a native NSError object, and inside of the NSErrors user dictionary you can obtain the MSError object.

Checking the Error

There are a few different types of errors that can occur during a network call. These error types are defined in MSConstants.h. To retrieve any info about the error, look in the userInfo dictionary with the key defined by MSErrorKey.

Client Errors

To check if an error is a client error, you can call [error isClientError] and [error clientError], like this:

[[[[[graphClient me] drive] items:@"foo"] request] getWithCompletion:^(MSGraphDriveItem *item, NSError *error){
    if (error && [error isClientError]){
        [self handleClientError:[error clientError]];
    }
}];

To check the code of an error, you can call the matches method on an error:

if ([msError matches:@"accessDenied"]){
    // handle access denied error
}

Each error object has a message as well as code. This message is for debugging purpose and is not be meant to be displayed to the user. Common error codes have been defined in MSErrorCodes.h.