feat: support for swift codables

[sisoje]

Feature Request

using swift codables for call.resolve()

Description

using swift codables for call.resolve()

Platform(s)

ios

Preferred Solution

using swift codables for call.resolve()

Alternatives

Additional Context

[jcesarmobile]

can you elaborate?

[sisoje]

I can, currently resolve takes a dictionary [String:Any] as an argument here:

  func resolve(_ data: PluginResultData = [:]) {
    successHandler(CAPPluginCallResult(data), self)
  }

So I have to make a dictionary even though in reality we dont need a dictionary but a json object (json data/string) shown here:

  public func toJson() throws -> String {
    do {
      if JSONSerialization.isValidJSONObject(result) {
        let theJSONData = try JSONSerialization.data(withJSONObject: result, options: [])
        
        return String(data: theJSONData,
                      encoding: .utf8)!
      } else {
        CAPLog.print("[Capacitor Plugin Error] - \(call.pluginId) - \(call.method) - Unable to serialize plugin response as JSON." +
          "Ensure that all data passed to success callback from module method is JSON serializable!")
        throw JSProcessingError.jsonSerializeError(call: call)
      }
    } catch let error as JSProcessingError {
      throw error
    } catch {
      CAPLog.print("Unable to serialize plugin response as JSON: \(error.localizedDescription)")
    }
    
    return "{}"
  }
}

in ObjC language that was normal, but in Swift it is much better to use structures that conform to Codable (Encodable) so we can have compile time type safety.

I made an quick extension for that, but I'm not sure if its the best solution because we still do unnecesary data YOYO-ing because capacitor still requires [String:Any]:

extension CAPPluginCall {
    /**
     Converting swift encodable to the [String: Any] needed by capacitor
     */
    static func makePluginResultData<T: Encodable>(encodable: T) -> PluginResultData {
        let data = try! JSONEncoder().encode(encodable)
        return try! JSONSerialization.jsonObject(with: data) as! PluginResultData
    }

    func resolve<T: Encodable>(encodable: T) {
        resolve(Self.makePluginResultData(encodable: encodable))
    }
}

[sisoje]

BTW call,error() also uses dictionaries, that could be extended to codables

[ikeith]

This makes sense to me and I've had a similar thought. We do support Obj-C but prefer/encourage Swift so adding first-class support for its conventions where we can is valuable. I have started on updating some of the JS<->Native type wrangling here but intend to tackle some bigger refactoring after we have split apart the plugins. The extra serialization proposed here definitely has some drawbacks but I think it should be possible to build in a more efficient solution when updating the related code. I'm adding this to the 3.0 roadmap.

[mzekrallah]

any update on this guys ? it's really important to have this flexibility i think.

[finnp]

Are there any downsides of using JSON Encoder? Is it slower? It would save me some headaches if it just worked with Codable

[ettore]

Any update on supporting Codable in Capacitor? It is definitely less than ideal to not being able to use it in CAPPluginCalls and notifications. Official docs do not mention it, I'm wondering if there is still a plan to support it. If not, it would be good to describe a workaround to be able to use Codable somehow (I'm guessing using let data = JSONSerialization.data(withJSONObject: call.dictionaryRepresentation) and then JSONDecoder().decode(data), although it seems very inefficient assuming it even works reliably.)

[jcesarmobile]

implemented on #7119

[ionitron-bot]

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