Cannot conform to objective-c protocol in swift

Question

I'm trying to implement the awesome library JSQMessagesViewController but I keep getting the error "'ModelMessage' does not conform to protocol 'JSQMessageData'" even though my class inherit from NSObject and I implement the required properties

Here is the protocol:

@protocol JSQMessageData <NSObject>

@required
 - (NSString *)senderId;
 - (NSString *)senderDisplayName;
 - (NSDate *)date;
 - (BOOL)isMediaMessage;
 - (NSUInteger)messageHash;

 @optional
 - (NSString *)text;
 - (id<JSQMessageMediaData>)media;

@end

and here is my class

import Foundation

class ModelMessage: Model, JSQMessageData {

/* Required */
var senderId: NSString
var senderDisplayName: NSString
var date: NSDate
var isMediaMessage: Bool
var messageHash: UInt
/**/

var text_: String

var id:String!
var conversationId: String!
var imageUrl: String?
var recipientId: String!
var recipientRead: Bool!

var avatar: NSData?


init(data: NSDictionary){

    super.init()

    /* Required */
    self.senderId = getStringFromJSON(data, key:"senderId")
    self.senderDisplayName = "Me"
    let dateString = getStringFromJSON(data, key: "timeStamp")
    let dateDouble = (dateString as NSString).doubleValue / 1000.0
    self.date = NSDate(timeIntervalSince1970: dateDouble)
    self.isMediaMessage = false
    /**/

    self.text_ = getStringFromJSON(data, key:"text")

    self.id = getStringFromJSON(data, key:"id")
    self.conversationId = getStringFromJSON(data, key:"conversationId")
    self.recipientId = getStringFromJSON(data, key:"recipientId")
    self.recipientRead = data["recipientRead"] as! Bool

}

}

which inherit from

import Foundation

class Model: NSObject
{

func getStringFromJSON(data: NSDictionary, key: String) -> String {

    if let info = data[key] as? String{
        return info
    }
    return ""

}

}

Answer 1

Try using implicitly unwrapped optionals when implementing ObjC protocols without nullability annotations. Also you can and should always use String instead of NSString.

var senderId: String!
var senderDisplayName: String!
var date: NSDate!
var isMediaMessage: Bool
var messageHash: UInt

Annotating the whole class and/or the properties with @objc could also help.

If that still doesn't work then check the build log as it will tell you what protocol function is missing or not implemented correctly.

Answer 2

try this

import Foundation

class ModelMessage: NSObject , JSQMessageData {

/* Required */
var senderId: NSString
var senderDisplayName: NSString
var date: NSDate
var isMediaMessage: Bool
var messageHash: UInt
/**/

var text_: String

var id:String!
var conversationId: String!
var imageUrl: String?
var recipientId: String!
var recipientRead: Bool!

var avatar: NSData?


init(data: NSDictionary){

    super.init()

    /* Required */
    self.senderId = getStringFromJSON(data, key:"senderId")
    self.senderDisplayName = "Me"
    let dateString = getStringFromJSON(data, key: "timeStamp")
    let dateDouble = (dateString as NSString).doubleValue / 1000.0
    self.date = NSDate(timeIntervalSince1970: dateDouble)
    self.isMediaMessage = false
    /**/

    self.text_ = getStringFromJSON(data, key:"text")

    self.id = getStringFromJSON(data, key:"id")
    self.conversationId = getStringFromJSON(data, key:"conversationId")
    self.recipientId = getStringFromJSON(data, key:"recipientId")
    self.recipientRead = data["recipientRead"] as! Bool

}

func getStringFromJSON(data: NSDictionary, key: String) -> String {

    if let info = data[key] as? String{
        return info
    }
    return ""

}


}