Files
firebase-ios-sdk/Firestore/Swift/Source/Codable/Timestamp+Codable.swift
T
Hui-Wu 1de21a845f Firestore swift Codable support (#3198)
FirestoreEncoder/Decoder and Timestamp/GeoPoint codable support.
2019-06-19 10:00:17 -04:00

63 lines
2.2 KiB
Swift

/*
* Copyright 2019 Google
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import FirebaseFirestore
/**
* A protocol describing the encodable properties of a Timestamp.
*
* Note: this protocol exists as a workaround for the Swift compiler: if the Timestamp class
* was extended directly to conform to Codable, the methods implementing the protocol would be need
* to be marked required but that can't be done in an extension. Declaring the extension on the
* protocol sidesteps this issue.
*/
private protocol CodableTimestamp: Codable {
var seconds: Int64 { get }
var nanoseconds: Int32 { get }
init(seconds: Int64, nanoseconds: Int32)
}
/** The keys in a Timestamp. Must match the properties of CodableTimestamp. */
private enum TimestampKeys: String, CodingKey {
case seconds
case nanoseconds
}
/**
* An extension of Timestamp that implements the behavior of the Codable protocol.
*
* Note: this is implemented manually here because the Swift compiler can't synthesize these methods
* when declaring an extension to conform to Codable.
*/
extension CodableTimestamp {
public init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: TimestampKeys.self)
let seconds = try container.decode(Int64.self, forKey: .seconds)
let nanoseconds = try container.decode(Int32.self, forKey: .nanoseconds)
self.init(seconds: seconds, nanoseconds: nanoseconds)
}
public func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: TimestampKeys.self)
try container.encode(seconds, forKey: .seconds)
try container.encode(nanoseconds, forKey: .nanoseconds)
}
}
/** Extends Timestamp to conform to Codable. */
extension Timestamp: CodableTimestamp {}