Can't retrieve data from DynamoDB using MobileHub

Question

I can succeed to retrieve data from a DynamoDB table.

func myRequest(completionHandler: (response: AWSDynamoDBObjectModel?, error: NSError?) -> Void) {

let objectMapper = AWSDynamoDBObjectMapper.defaultDynamoDBObjectMapper()

objectMapper.load(myModel.self,
                          hashKey: AWSIdentityManager.defaultIdentityManager().identityId!,
                          rangeKey: nil,
                          completionHandler: {(response: AWSDynamoDBObjectModel?, error: NSError?) -> Void in
            dispatch_async(dispatch_get_main_queue(), {
                completionHandler(response: response, error: error)
            })
        })


    }

Completion handler complain response is nil but log indicates there is a response which content is the expected one.

So it seems the problem occurs on mapping JSON response to table' model myModel.

To obtain myModel I simply took sample app from Mobile Hub and replace existing fields by the one I use.

Answer 1

Problem solved: model properties contained capital letters. Removing them make the process work.

Hereafter is presented the non working code. In the project field name on DynamoDB must begin with a capital letter. I then created properties following this rule, with an added prefixing underscore.

class MyModel: AWSDynamoDBObjectModel, AWSDynamoDBModeling {

var _UserId: String?
var _ArticleId: String?


class func dynamoDBTableName() -> String {

    return "myTable"
}

class func hashKeyAttribute() -> String {

    return "_UserId"
}

class func rangeKeyAttribute() -> String {

    return "_ArticleId"
}

override class func JSONKeyPathsByPropertyKey() -> [NSObject : AnyObject] {
    return [
           "_UserId" : "UserId",
           "_ArticleId" : "ArticleId",

    ]
}

}

An this is the working code:

class MyModel: AWSDynamoDBObjectModel, AWSDynamoDBModeling {

var _userId: String?
var _articleId: String?


class func dynamoDBTableName() -> String {

    return "myTable"
}

class func hashKeyAttribute() -> String {

    return "_userId"
}

class func rangeKeyAttribute() -> String {

    return "_articleId"
}

override class func JSONKeyPathsByPropertyKey() -> [NSObject : AnyObject] {
    return [
           "_userId" : "UserId",
           "_articleId" : "ArticleId",

    ]
}

}

Strange, isn't it?