嗨,我尝试学习RXSwift。我第一次遇到这些概念,例如Maps和Compact Maps。
我能够得到响应,但是此行始终返回空。
objects.compactMap(DummyUser.init)
fileprivate let Users = Variable<[DummyUser]>([])
fileprivate let bag = DisposeBag()
response
.filter { response, _ in
return 200..<300 ~= response.statusCode
}
.map { _, data -> [[String: Any]] in
guard (try? JSONSerialization.jsonObject(with: data, options: [])) != nil else {
return []
}
let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String : Any]
// print(json!["results"])
return json!["results"] as! [[String : Any]]
}
.filter { objects in
return objects.count > 0
}
.map { objects in
// objects.forEach{print($0["name"]!)}
let names = objects.map { $0["name"]!}
print(names)
return objects.compactMap(DummyUser.init)
}
.subscribe(onNext: { [weak self] newEvents in
self?.processEvents(newEvents)
})
.disposed(by: bag)
func processEvents(_ newEvents: [DummyUser]) {
var updatedEvents = newEvents + Users.value
if updatedEvents.count > 50 {
updatedEvents = Array<DummyUser>(updatedEvents.prefix(upTo: 50))
}
Users.value = updatedEvents
DispatchQueue.main.async {
self.MianUsertable.reloadData()
}
// refreshControl?.endRefreshing()
let eventsArray = updatedEvents.map{ $0.dictionary } as NSArray
eventsArray.write(to: userFileURL, atomically: true)
}
我的Json回应在这里
https://randomuser.me/api/?results=5
DummyUser类
import Foundation
typealias AnyDict = [String: Any]
class DummyUser {
let gender: String
let name: AnyDict
let dob: String
let picture: AnyDict
init?(dictionary: AnyDict) {
guard let Dgender = dictionary["gender"] as? String,
let Dname = dictionary["name"] as? AnyDict,
let birthdata = dictionary["dob"] as? AnyDict,
let Ddob = birthdata["dob"] as? String,
let Dpicture = dictionary["picture"] as? AnyDict
else {
return nil
}
gender = Dgender
name = Dname
dob = Ddob
picture = Dpicture
}
var dictionary: AnyDict {
return [
"user": ["name" : name, "gender": gender, "dob": dob],
"picture" : ["userImage": picture]
]
}
}
最佳答案
在DummyUser
模型中,您使用的是失败的初始化程序,因此,如果为init方法提供的词典错误,它将返回nil
。compactMap
自动自动过滤nil
,这就是您的输出为空的原因。
看这段代码:
let names = objects.map { $0["name"]!}
return objects.compactMap(DummyUser.init)
我会调试名为
names
的变量,因为它可能为DummyUser
初始化程序输入了错误。它应该是包含所有DummyUser
参数的字典。您还可以调试失败的初始化程序,以查看缺少哪个参数。