-
Notifications
You must be signed in to change notification settings - Fork 104
/
XMLUnkeyedDecodingContainer.swift
234 lines (197 loc) · 7.98 KB
/
XMLUnkeyedDecodingContainer.swift
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
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
//
// XMLUnkeyedDecodingContainer.swift
// XMLCoder
//
// Created by Shawn Moore on 11/21/17.
// Copyright © 2017 Shawn Moore. All rights reserved.
//
import Foundation
struct XMLUnkeyedDecodingContainer: UnkeyedDecodingContainer {
// MARK: Properties
/// A reference to the decoder we're reading from.
private let decoder: XMLDecoderImplementation
/// A reference to the container we're reading from.
private let container: SharedBox<UnkeyedBox>
/// The path of coding keys taken to get to this point in decoding.
public private(set) var codingPath: [CodingKey]
/// The index of the element we're about to decode.
public private(set) var currentIndex: Int
// MARK: - Initialization
/// Initializes `self` by referencing the given decoder and container.
init(referencing decoder: XMLDecoderImplementation, wrapping container: SharedBox<UnkeyedBox>) {
self.decoder = decoder
self.container = container
codingPath = decoder.codingPath
currentIndex = 0
}
// MARK: - UnkeyedDecodingContainer Methods
public var count: Int? {
return container.withShared { unkeyedBox in
unkeyedBox.count
}
}
public var isAtEnd: Bool {
return currentIndex >= count!
}
public mutating func decodeNil() throws -> Bool {
guard !isAtEnd else {
throw DecodingError.valueNotFound(Any?.self, DecodingError.Context(
codingPath: decoder.codingPath + [XMLKey(index: self.currentIndex)],
debugDescription: "Unkeyed container is at end."
))
}
let isNull = container.withShared { unkeyedBox in
unkeyedBox[self.currentIndex].isNull
}
if isNull {
currentIndex += 1
return true
} else {
return false
}
}
public mutating func decode<T: Decodable>(_ type: T.Type) throws -> T {
return try decode(type) { decoder, box in
try decoder.unbox(box)
}
}
private mutating func decode<T: Decodable>(
_ type: T.Type,
decode: (XMLDecoderImplementation, Box) throws -> T?
) throws -> T {
guard let strategy = self.decoder.nodeDecodings.last else {
preconditionFailure("Attempt to access node decoding strategy from empty stack.")
}
decoder.codingPath.append(XMLKey(index: currentIndex))
let nodeDecodings = decoder.options.nodeDecodingStrategy.nodeDecodings(
forType: T.self,
with: decoder
)
decoder.nodeDecodings.append(nodeDecodings)
defer {
_ = decoder.nodeDecodings.removeLast()
_ = decoder.codingPath.removeLast()
}
guard !isAtEnd else {
throw DecodingError.valueNotFound(type, DecodingError.Context(
codingPath: decoder.codingPath + [XMLKey(index: self.currentIndex)],
debugDescription: "Unkeyed container is at end."
))
}
decoder.codingPath.append(XMLKey(index: currentIndex))
defer { self.decoder.codingPath.removeLast() }
let box = container.withShared { unkeyedBox in
unkeyedBox[self.currentIndex]
}
var value: T?
if let singleKeyed = box as? SingleKeyedBox {
do {
value = try decode(decoder, singleKeyed)
} catch {
do {
// Drill down to the element in the case of an nested unkeyed element
value = try decode(decoder, singleKeyed.element)
} catch {
// Specialize for choice elements
value = try decode(decoder, ChoiceBox(key: singleKeyed.key, element: singleKeyed.element))
}
}
} else {
value = try decode(decoder, box)
}
defer { currentIndex += 1 }
if value == nil, let type = type as? AnyOptional.Type,
let result = type.init() as? T {
return result
}
guard let decoded: T = value else {
throw DecodingError.valueNotFound(type, DecodingError.Context(
codingPath: decoder.codingPath + [XMLKey(index: self.currentIndex)],
debugDescription: "Expected \(type) but found null instead."
))
}
return decoded
}
public mutating func nestedContainer<NestedKey>(
keyedBy _: NestedKey.Type
) throws -> KeyedDecodingContainer<NestedKey> {
decoder.codingPath.append(XMLKey(index: currentIndex))
defer { self.decoder.codingPath.removeLast() }
guard !isAtEnd else {
throw DecodingError.valueNotFound(
KeyedDecodingContainer<NestedKey>.self, DecodingError.Context(
codingPath: codingPath,
debugDescription: "Cannot get nested keyed container -- unkeyed container is at end."
)
)
}
let value = self.container.withShared { unkeyedBox in
unkeyedBox[self.currentIndex]
}
guard !value.isNull else {
throw DecodingError.valueNotFound(KeyedDecodingContainer<NestedKey>.self, DecodingError.Context(
codingPath: codingPath,
debugDescription: "Cannot get keyed decoding container -- found null value instead."
))
}
guard let keyedContainer = value as? SharedBox<KeyedBox> else {
throw DecodingError.typeMismatch(at: codingPath,
expectation: [String: Any].self,
reality: value)
}
currentIndex += 1
let container = XMLKeyedDecodingContainer<NestedKey>(
referencing: decoder,
wrapping: keyedContainer
)
return KeyedDecodingContainer(container)
}
public mutating func nestedUnkeyedContainer() throws -> UnkeyedDecodingContainer {
decoder.codingPath.append(XMLKey(index: currentIndex))
defer { self.decoder.codingPath.removeLast() }
guard !isAtEnd else {
throw DecodingError.valueNotFound(
UnkeyedDecodingContainer.self, DecodingError.Context(
codingPath: codingPath,
debugDescription: "Cannot get nested keyed container -- unkeyed container is at end."
)
)
}
let value = container.withShared { unkeyedBox in
unkeyedBox[self.currentIndex]
}
guard !value.isNull else {
throw DecodingError.valueNotFound(UnkeyedDecodingContainer.self, DecodingError.Context(
codingPath: codingPath,
debugDescription: "Cannot get keyed decoding container -- found null value instead."
))
}
guard let unkeyedContainer = value as? SharedBox<UnkeyedBox> else {
throw DecodingError.typeMismatch(at: codingPath,
expectation: UnkeyedBox.self,
reality: value)
}
currentIndex += 1
return XMLUnkeyedDecodingContainer(referencing: decoder, wrapping: unkeyedContainer)
}
public mutating func superDecoder() throws -> Decoder {
decoder.codingPath.append(XMLKey(index: currentIndex))
defer { self.decoder.codingPath.removeLast() }
guard !isAtEnd else {
throw DecodingError.valueNotFound(Decoder.self, DecodingError.Context(
codingPath: codingPath,
debugDescription: "Cannot get superDecoder() -- unkeyed container is at end."
))
}
let value = container.withShared { unkeyedBox in
unkeyedBox[self.currentIndex]
}
currentIndex += 1
return XMLDecoderImplementation(
referencing: value,
options: decoder.options,
nodeDecodings: decoder.nodeDecodings,
codingPath: decoder.codingPath
)
}
}