Swift ObjectMapper：toJSONString用于包含可映射对象的字典

Question

I would like to to get the json string for the following Dictionary, but I don't know what is the appropriate way to do so.

/* For example, I have a Dictionary contains a set of users and I want to get the JSONString of it. */

class User: Mappable {
    // some other implemenation ...
}

/* in some other class, e.g MyService.swift */
func generateString() -> String {
    let user1 = User()
    let user2 = User()

    // some other implemenation ...

    let seatDict: [String:User] = [
       "1A": user1,
       "1B": user2,
       // some other implemenation ...
       // some other implemenation ...
    ]

    // here i would like to return the JsonString of my seatDict
    let result: String = ... // how to do it?
    return result
}

Answer 1

You can do this by using the Mapper class.

...
// here i would like to return the JsonString of my seatDict
let jsonDict = Mapper<User>().toJSONDictionary(seatDict)
let result: String? = Mapper<User>.toJSONString(jsonDict as Any, prettyPrint: false)
return result

Keep in mind that toJSONString can return nil if serialisation fails - so you need to handle that somehow in your application. That's why I changed result to be optional