SwiftUI_apiCall_Combine

SwiftUI_apiCall_Combine

import Foundation
import Combine


enum HttpMethod:String {
    case get = "GET"
    case post = "POST"
    case put = "PUT"
    case delete = "DELETE"
}

enum NetworkError:Error {
    case invlaidURL
    case serverError(Int)
    case decodingError
    case unknown
}

class APIService {
    
    static let shared = APIService()
    private init(){ }
    
    func request<T:Codable>(endpoint:String, method:HttpMethod = .get, headers: [String: String]? = nil, parameters: [String: Any]? = nil)  -> AnyPublisher<T, Error> {
        
        guard let url = URL(string: endpoint) else {
            return Fail(error: NetworkError.invlaidURL).eraseToAnyPublisher()
        }
        
        var request = URLRequest(url: url)
        request.httpMethod = method.rawValue
        headers?.forEach {
            request.addValue($0.value, forHTTPHeaderField: $0.key)
        }
        
        if let parameters {
            request.httpBody = try? JSONSerialization.data(withJSONObject: parameters)
            request.addValue("application/json", forHTTPHeaderField: "Content-Type")
        }
        
        let urlsession = URLSession.shared.dataTaskPublisher(for: request)
        
        // 1. Check for HTTP status codes
            .tryMap { output in
                
                guard let response = output.response as? HTTPURLResponse, (200...299).contains(response.statusCode) else {
                    throw NetworkError.serverError((output.response as? HTTPURLResponse)?.statusCode ?? 500)
                }
                return output.data
            }
        // 2. Decode the JSON
            .decode(type: T.self, decoder: JSONDecoder())
        
        // 3. Move back to the Main Thread for UI updates
            .receive(on: DispatchQueue.main)
        // 4. Erase type to make it reusable
            .eraseToAnyPublisher()
        
        return urlsession

    }
}


=========

import Foundation



enum APIEndPoint {
    static let baseURL = "https://newsapi.org/v2/everything?q=tesla&from=2026-01-10&sortBy=publishedAt&apiKey="
    
    case news
    
    var url:String {
        switch self {
        case .news : return "\(APIEndPoint.baseURL)"
        }
    }
}

ViewModel_call

import Foundation
import Combine



class NewsViewModel:ObservableObject {
    
    @Published var newList:[Articles] = []
    @Published var errorMessage:String?
    @Published var showError:Bool = false
    
    // This stores your subscriptions so they don't get cancelled immediately
    private var cancellables = Set<AnyCancellable>()
    
    init() {
        getNews()
    }
    
    
    
    func getNews() {
        let publisher: AnyPublisher<NewsModelRes, Error> = APIService.shared.request(endpoint: APIEndPoint.news.url)
        
        //Publisher: URLSession starts the data flow.
        publisher
            .receive(on: DispatchQueue.main)
        // Specifying the type we expect (NewsResponse)
            .sink { [weak self] completion in
                switch completion {
                case .finished:
                    break // Do nothing on success
                case .failure(let error):
                    self?.errorMessage = error.localizedDescription
                    self?.showError = true
                }
            } receiveValue: { [weak self] response in
                // This only runs if the request succeeds
                self?.newList = response.articles ?? []
            }
            .store(in: &cancellables) // Keep the subscription alive
        
    }
}


//POST
//let response:NewsModelRes = try await APIService.shared.request(endpoint: APIEndPoint.news.url, method: .put, headers: nil, parameters: [:])


===================


import Foundation


struct NewsModelRes:Codable {
    
    let status:String?
    let totalResults:Int?
    let articles:[Articles]?
    
    enum CodingKeys: String, CodingKey {
        case status
        case totalResults
        case articles
    }
}

struct Articles:Codable, Identifiable {
    var id : String {url ?? ""}
        let author: String?
        let title: String?
        let description: String?
        let url: String?
        let urlToImage: String?
    
    enum CodingKeys: String, CodingKey {
        
        case author
        case title
        case description
        case url
        case urlToImage
    }
}