Amazon AWS SNS: How do i subscribe to SNS topic from iOS?

Question

First of all I found the same question here, but it doesn't work... Maybe AWS SDK changes or something else, I don't know why... I want to subscribe to SNS topic from my iOS app. I am trying to do it with code from that answer, which I tried to change to get rid of errors:

AWSSNS *sns = [AWSSNS defaultSNS];

    AWSSNSCreatePlatformEndpointInput *endpointRequest = [AWSSNSCreatePlatformEndpointInput new];

    endpointRequest.platformApplicationArn = @"arn:aws:sns:us-east-1:753780999999:app/APNS_SANDBOX/MyAppDevelopment";
    endpointRequest.token = [self deviceTokenAsString:deviceToken]; 

    [[[sns createPlatformApplication:endpointRequest] continueWithSuccessBlock:^id(AWSTask *task) {

        AWSSNSCreateEndpointResponse *response = task.result;

        AWSSNSSubscribeInput *subscribeRequest = [AWSSNSSubscribeInput new];

        subscribeRequest.endpoint = response.endpointArn;
        subscribeRequest.protocols = @"application";
        subscribeRequest.topicArn = @"arn:aws:sns:us-east-1:753780999999:MyAppDevelopingTest";

        return [sns subscribe:subscribeRequest];

    }] continueWithBlock:^id(AWSTask *task) {

        if (task.cancelled) {
            NSLog(@"Task cancelled");
        }

        else if (task.error) {
            NSLog(@"Error occurred: [%@]", task.error);
        }

        else {
            NSLog(@"Success");
        }

        return nil;

    }];

But I get the error:

Error occurred: [Error Domain=com.amazonaws.AWSSNSErrorDomain Code=0 "The operation couldn’t be completed. (com.amazonaws.AWSSNSErrorDomain error 0.)" UserInfo=0x17ee0950 {Type=Sender, Message=3 validation errors detected: Value null at 'name' failed to satisfy constraint: Member must not be null; Value null at 'attributes' failed to satisfy constraint: Member must not be null; Value null at 'platform' failed to satisfy constraint: Member must not be null, __text=(
    "\n    ",
    "\n    ",
    "\n    ",
    "\n  "
), Code=ValidationError}]

Why so? Why does the resource cut after app/ is it ok? Beside this I don't understand where I should put deviceToken? I really need help! Thanks in advance?

My Cognito role is:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "sns:CreatePlatformEndpoint",
                "sns:Subscribe",
                "sns:CreatePlatformApplication",
                "sns:*"
            ],
            "Resource": [
                "arn:aws:sns:*"
            ]
        }
    ]
}

I am using the latest AWS SDK:

Installing AWSCognito 2.2.1 (was 2.2.0)
Installing AWSCore 2.2.1 (was 2.2.0)
Installing AWSSNS 2.2.1 (was 2.2.0)

Answer 1

Sorry, unfortunately you copied code that included a typo:

createPlatformApplication:endpointRequest

Should be:

createPlatformEndpoint:endpointRequest

The method CreatePlatformApplication was not allowed in your original policy. Once you allowed sns:*, the call was allowed by the service, but the request didn't include the required parameters for CreatePlatformApplication, hence the ValidationError. The trimmed ARN in your original message is also a result of lack of parameters for CreatePlatformApplication.