Objectmapper: Swift 5 and try?

[YevhenHerasymenko]

Parsing complicated object with optional objects as a parameter does not work.

public struct Push: ImmutableMappable {
  public let contact: MeetingContactPush?

  public init(map: Map) throws {
    contact = try? map.value("Contact")
  }

}

public struct MeetingContactPush: ImmutableMappable {

  public let userId: Int
  public let phone: String
  public let name: String?

  public init(map: Map) throws {
    userId = try map.value("Id")
    phone = try map.value("Phone")
    name = try? map.value("Name")
  }

}

Contact will be always nil

[OleksiiShvachenko]

try this workaround:
contact = try? map.value("Contact") as MeetingContactPush

[gim-]

I've been scratching my head around this which is probably related:

Using @shalex9154 workaround helped. Thanks!

[sanoj00b]

Hey is project is building with Swift 5 and XCode 10.2??

[artemisia-absynthium]

Yes, it can build, but it gives this bug, a lot of warnings in console and it causes the "Migration to Swift 5 available" message to keep appearing even after said migration has been done. Please migrate and update pod 🙏🏻

[sanoj00b]

@artemisia-absynthium which version are you targetting in Carthage?

[artemisia-absynthium]

@sanoj00b version 3.4.2, actually I'm using Cocoapods, to be precise.

[tbechtum]

In ObjectMapper 3.4.2 there are 43 Xcode 10.2 redundant warnings regarding modifiers public and internal for extension methods. This could be easily resolved by removing them in order to keep the warnings overview in our main projects.

Example

public extension Array where Element: BaseMappable {

    /// Initialize Array from a JSON String
    **public** init?(JSONString: String, context: MapContext? = nil) {
        if let obj: [Element] = Mapper(context: context).mapArray(JSONString: JSONString) {
            self = obj
        } else {
            return nil
        }
    }

Resolve: remove public modifier of above mentioned optional init method. This changes will be compatible also to Swift 4.2 projects (checked this already).

Thanks for your time and effort, cheers Thomas

[sanoj00b]

I am facing this issue, is anybody did get the resolution. Xcode 10.2 with Swift5

[ghost]

It's still an issues - completely unable to parse optional enum values.

[sanoj00b]

I am facing this issue, is anybody did get the resolution. Xcode 10.2 with Swift5

Can anybody let me know about this? Please

[abhisheksingh9891]

I am facing the same error of getting nil but I am unable to solve it by typecasting it.

Below is the piece of code which is causing issue:-

let transferJSON = "{\"metadata\":{\"resultData\":[{\"execEngineRef\":\"20170821/XXXX/489044757287\",\"transactionID\":\"28954894\",\"resultDetail\":[{\"result\":\"SOK\",\"status\":\"SUCCESS\",\"operationReference\":\"TRANSACTION\"}]}]}}"

let genericTransferResponse = try? Mapper<GenericPostResponse<TransactionResponse>>().map(JSONString: transferJSON)

Doesn't change anything to typecast this with GenericPostResponse<TransactionResponse>.

genericTransferResponse will always be nil.

[evilutioner]

@sanoj00b if you are using Cocoapods you could remove folder Pods/ObjectMapper and run pod install for rebuilding the module with Swift 5 compiler (in compatibility mode with Swift 4.2)

[sanoj00b]

@evilutioner I am using Carthage.

[evilutioner]

@sanoj00b For Carthage:

1. Select command line tool Xcode 10.2.x (by command xcode-select or Xcode IDE)
2. carthage update ObjectMapper --no-use-binaries

[felipe-azevedo]

I'd like @cddjr's fix: https://github.com/cddjr/ObjectMapper/commit/2066cb86d89aba890f7067a3f8e546acf1474c9e
released as 5.2.2 so that I can effectively use this library with Swift 5.
@tristanhimmelman please provide this.

[felipe-azevedo]

@tristanhimmelman please use @cddjr's fix so that this lib is useable.

[tristanhimmelman]

@felipe-azevedo @cddjr If you create a PR I can merge in the fix. I unfortunately don't have the time to put this in myself.

[mickamy]

https://github.com/tristanhimmelman/ObjectMapper/pull/1057
I opened PR with @cddjr's fix.
@tristanhimmelman Would you please merge it and release new version, please?

[pmusolino]

Any news on this? :( It's really sad to see a library with a lot of users abandoned in this way.

[ghost]

@pmusolino we've added public extension Map into ImmutableMappable.swift, extension ImmutableMappable in our own codebase and all seems to work as needed. Kinda creppy but the only possible way for now. Just use like try? User(dictionary: dictionary), not (JSON:_) version directly

extension ImmutableMappable {
    init(dictionary: [String: Any], context: MapContext? = nil) throws {
        self = try Mapper(context: nil).map(JSON: dictionary)
    }
}

// optional value mappers
public extension Map {
    /// Returns a RawRepresentable type or throws an error.
    public func value<T: RawRepresentable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> T? {
        return try self.value(key, nested: nested, delimiter: delimiter, using: EnumTransform(), file: file, function: function, line: line)
    }

    /// Returns a `[RawRepresentable]` type or throws an error.
    public func value<T: RawRepresentable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [T]? {
        return try self.value(key, nested: nested, delimiter: delimiter, using: EnumTransform(), file: file, function: function, line: line)
    }

    /// Returns a `BaseMappable` object or throws an error.
    public func value<T: BaseMappable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> T? {
        let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
        guard let JSONObject = currentValue else {
            throw MapError(key: key, currentValue: currentValue, reason: "Found unexpected nil value", file: file, function: function, line: line)
        }
        return try Mapper<T>(context: context).mapOrFail(JSONObject: JSONObject)
    }

    /// Returns a `[BaseMappable]` or throws an error.
    public func value<T: BaseMappable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [T]? {
        let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
        guard let jsonArray = currentValue as? [Any] else {
            throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[Any]'", file: file, function: function, line: line)
        }

        return try jsonArray.map { JSONObject -> T in
            return try Mapper<T>(context: context).mapOrFail(JSONObject: JSONObject)
        }
    }

    /// Returns a `[BaseMappable]` using transform or throws an error.
    public func value<Transform: TransformType>(_ key: String, nested: Bool? = nil, delimiter: String = ".", using transform: Transform, file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [Transform.Object]? {
        let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
        guard let jsonArray = currentValue as? [Any] else {
            throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[Any]'", file: file, function: function, line: line)
        }

        return try jsonArray.map { json -> Transform.Object in
            guard let object = transform.transformFromJSON(json) else {
                throw MapError(key: "\(key)", currentValue: json, reason: "Cannot transform to '\(Transform.Object.self)' using \(transform)", file: file, function: function, line: line)
            }
            return object
        }
    }

    /// Returns a `[String: BaseMappable]` or throws an error.
    public func value<T: BaseMappable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [String: T]? {

        let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
        guard let jsonDictionary = currentValue as? [String: Any] else {
            throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[String: Any]'", file: file, function: function, line: line)
        }
        var value: [String: T] = [:]
        for (key, json) in jsonDictionary {
            value[key] = try Mapper<T>(context: context).mapOrFail(JSONObject: json)
        }
        return value
    }

    /// Returns a `[String: BaseMappable]` using transform or throws an error.
    public func value<Transform: TransformType>(_ key: String, nested: Bool? = nil, delimiter: String = ".", using transform: Transform, file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [String: Transform.Object]? {

        let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
        guard let jsonDictionary = currentValue as? [String: Any] else {
            throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[String: Any]'", file: file, function: function, line: line)
        }
        var value: [String: Transform.Object] = [:]
        for (key, json) in jsonDictionary {
            guard let object = transform.transformFromJSON(json) else {
                throw MapError(key: key, currentValue: json, reason: "Cannot transform to '\(Transform.Object.self)' using \(transform)", file: file, function: function, line: line)
            }
            value[key] = object
        }
        return value
    }

    // MARK: [[BaseMappable]]
    /// Returns a `[[BaseMappable]]` or throws an error.
    public func value<T: BaseMappable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [[T]]? {

        let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
        guard let json2DArray = currentValue as? [[Any]] else {
            throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[[Any]]'", file: file, function: function, line: line)
        }
        return try json2DArray.map { jsonArray in
            try jsonArray.map { jsonObject -> T in
                return try Mapper<T>(context: context).mapOrFail(JSONObject: jsonObject)
            }
        }
    }

    /// Returns a `[[BaseMappable]]` using transform or throws an error.
    public func value<Transform: TransformType>(_ key: String, nested: Bool? = nil, delimiter: String = ".", using transform: Transform, file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [[Transform.Object]]? {

        let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
        guard let json2DArray = currentValue as? [[Any]] else {
            throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[[Any]]'",
                           file: file, function: function, line: line)
        }

        return try json2DArray.map { jsonArray in
            try jsonArray.map { json -> Transform.Object in
                guard let object = transform.transformFromJSON(json) else {
                    throw MapError(key: "\(key)", currentValue: json, reason: "Cannot transform to '\(Transform.Object.self)' using \(transform)", file: file, function: function, line: line)
                }
                return object
            }
        }
    }
}

[tristanhimmelman]

I've just merged the fix for this. Sorry for the delay!

The library has not been abandoned, I just do not have as much time as I used to to maintain it. If there are volunteers to help support I would be happy for the help.

[felipe-azevedo]

Thank you so much, folks!

[felipe-azevedo]

@tristanhimmelman, is there a way to reopen this?
The fix worked for most of the things, but it is still failing for mapping optional enums. They are always map to nil even though there is a value in the JSON.

[felipe-azevedo]

I think the issue I mentioned is going to be fixed on #1059.

[tbechtum]

Thanks for your work and effort: to me and my use cases ObjectMapper 3.5.0 and Swift 5 is working fine.