在列表中限制 API 个请求

Question

我有一个应用程序，我可以在其中进行 API 调用，让我可以从网站上获取货币。它代表所有货币，但我只需要将它们限制为 3 个“USD”、“KZT”、“AED”、“RUB”

我的获取代码如下：

import SwiftUI

class FetchData: ObservableObject {

@Published var coversionData: [Currency] = []
@Published var baseCode = "USD"

 init() {
        fetch()
    }
    
func fetch() {
    
    let url = "https://open.exchangerate-api.com/v6/latest?base=\(baseCode)"
    
    let session = URLSession(configuration: .default)
    session.dataTask(with: URL(string: url)!) { data, _, _ in
        
        guard let JSONData = data else {return}
        
        do {
            let conversion = try JSONDecoder().decode(Conversion.self, from: JSONData)
            
            DispatchQueue.main.async {
                self.coversionData = conversion.rates.compactMap({ (key,value) -> Currency? in
                    return Currency(currencyName: key, currencyValue: value)
                })
            }
        }
        catch {
            print(error)
        }
    }
    .resume()
}

func updateData(baseCode: String) {
    
    self.baseCode = baseCode
    
    self.coversionData.removeAll()
    fetch()
    
}
}

有人可以分享我的文档、教程、GitHub link 任何我只需要了解如何仅显示 3 个类别的内容吗？

或者例子，拜托！

Answer 1

     //Properties
     @Published var filteredCurrency = "KZT"


 //.Filter call
.filter({ Currency in
                        Currency.currencyName == self.filteredCurrency
                    })

这是一个答案，因为我相信我调用了一个 .filter 并确定 Currency.currency 名称将等于我给它的属性

现在我的代码看起来像这样

    import SwiftUI

class FetchData: ObservableObject {
    
    @Published var coversionData: [Currency] = []
    @Published var baseCode = "USD"
    @Published var filteredCurrency = "KZT"
    
init() {
    fetch()
}

func fetch() {
    
    let url = "https://open.exchangerate-api.com/v6/latest?base=\(baseCode)"
    
    let session = URLSession(configuration: .default)
    session.dataTask(with: URL(string: url)!) { data, _, _ in
        
        guard let JSONData = data else {return}
        
        do {
            let conversion = try JSONDecoder().decode(Conversion.self, from: JSONData)
            
            DispatchQueue.main.async {
                self.coversionData = conversion.rates.compactMap({ (key,value) -> Currency? in
                    return Currency(currencyName: key, currencyValue: value)
                })
                .filter({ Currency in
                    Currency.currencyName == self.filteredCurrency
                })
            }
        }
        catch {
            print(error)
        }
    }
    .resume()
}

func updateData(baseCode: String) {
    
    self.baseCode = baseCode
    


       self.coversionData.removeAll()
        fetch()
        
    }
    
}

在列表中限制 API 个请求

Limit API request in a list

swift

api

rest

fetch

call