我正在尝试将以下JSON解析为一个类,但不知道如何处理这种特殊情况。
我正在尝试获取标题和摘录,但是要这样做,需要我经过唯一的pageid。我如何使用可编码协议来做到这一点?
{
"batchcomplete": "",
"query": {
"normalized": [
{
"from": "bird",
"to": "Bird"
}
],
"pageids": [
"3410"
],
"pages": {
"3410": {
"pageid": 3410,
"ns": 0,
"title": "Bird",
"extract": "..."
}
}
}
}
我的建议是编写一个自定义初始化程序:
将pages
解码为[String:Page]
字典,并根据pageids
中的值映射内部字典>
let jsonString = """
{
"batchcomplete": "",
"query": {
"normalized": [
{
"from": "bird",
"to": "Bird"
}
],
"pageids": [
"3410"
],
"pages": {
"3410": {
"pageid": 3410,
"ns": 0,
"title": "Bird",
"extract": "..."
}
}
}
}
"""
struct Root : Decodable {
let query : Query
}
struct Query : Decodable {
let pageids : [String]
let pages : [Page]
private enum CodingKeys : String, CodingKey { case pageids, pages }
init(from decoder : Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
self.pageids = try container.decode([String].self, forKey: .pageids)
let pagesData = try container.decode([String:Page].self, forKey: .pages)
self.pages = self.pageids.compactMap{ pagesData[$0] }
}
}
struct Page : Decodable {
let pageid, ns : Int
let title, extract : String
}
let data = Data(jsonString.utf8)
do {
let result = try JSONDecoder().decode(Root.self, from: data)
print(result)
} catch {
print(error)
}