blob: fa563403c8dd1b4f52488073d3931a56fe52843a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
/*
* Copyright 2018 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 GeoPoint.
*
* Note: this protocol exists as a workaround for the Swift compiler: if the GeoPoint class was
* extended directly to conform to Codable, the methods implementing the protcol 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.
*/
fileprivate protocol CodableGeoPoint: Codable {
var latitude: Double { get }
var longitude: Double { get }
init(latitude: Double, longitude: Double)
}
/** The keys in a GeoPoint. Must match the properties of CodableGeoPoint. */
fileprivate enum GeoPointKeys: String, CodingKey {
case latitude
case longitude
}
/**
* An extension of GeoPoint 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 CodableGeoPoint {
public init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: GeoPointKeys.self)
let latitude = try container.decode(Double.self, forKey: .latitude)
let longitude = try container.decode(Double.self, forKey: .longitude)
self.init(latitude: latitude, longitude: longitude)
}
public func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: GeoPointKeys.self)
try container.encode(latitude, forKey: .latitude)
try container.encode(longitude, forKey: .longitude)
}
}
/** Extends GeoPoint to conform to Codable. */
extension GeoPoint: CodableGeoPoint {}
|
