D10- 用 Swift 和公开资讯，打造投资理财的 Apps { 台股申购实作.3-让申购资讯放进可以清楚理解的 TableView }

接下来，进行台股申购 Model 实作，这个 Model 该负责的任务如下

申购资料下载
申购列表总共数量
第 n 个列表是哪个申购资讯?

程序码如下

//
//  StockSubscriptionModel.swift
//  ITIronMan
//
//  Created by Marvin on 2021/9/4.
//

import Foundation

protocol StockSubscriptionModelDelegate: AnyObject {
    
    func didRecieveList(_ subscriptionList: [StockSubscriptionInfo], error: Error?)
}

/// 股票申购 VC 所需的 Model
class StockSubscriptionModel {
    
    weak var delegate: StockSubscriptionModelDelegate?
    
    var subscriptionList = [StockSubscriptionInfo]()
    
    private lazy var manager: StockSubscriptionManager = {
        return StockSubscriptionManager()
    }()
    
    var count: Int {
        return subscriptionList.count
    }
    
    func getSubscriptionInfo(at indexPath: IndexPath) -> StockSubscriptionInfo? {
        
        let index = indexPath.row
        
        if subscriptionList.indices.contains(index) {
            return subscriptionList[index]
        }
        
        return nil
    }
    
    func requestStockSubscription() {
        
        let year = 2021
        manager.requestStockSubscriptionInfo(year: year) { [weak self] subscriptionList, error in
            
            self?.subscriptionList = subscriptionList
            self?.delegate?.didRecieveList(subscriptionList, error: error)
        }
    }
}

要呈现的资料，先大概设计装载下列资讯

申购状态
股票名称
股票代号
申购价格
中签率

简单拉一个 UITableViewCell

然後 VC 负责把 View 和 Model 连结起来，程序码如下

//
//  StockSubscriptionViewController.swift
//  ITIronMan
//
//  Created by Marvin on 2021/9/4.
//

import UIKit

class StockSubscriptionViewController: UIViewController {
    
    @IBOutlet weak var tableView: UITableView!
    
    private lazy var model: StockSubscriptionModel = {
        let model = StockSubscriptionModel()
        model.delegate = self
        return model
    }()

    // MARK: - life cycle
    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
    }
    
    // MARK: - private methods
    private func setupUI() {
        tableView.dataSource = self
        tableView.delegate = self
    }
    
    // MARK: - IBAction
    @IBAction func requestSubscriptionButtonDidTap(_ sender: Any) {
        model.requestStockSubscription()
    }
    
}

extension StockSubscriptionViewController: UITableViewDelegate, UITableViewDataSource {
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return model.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        
        guard let cell = tableView.dequeueReusableCell(withIdentifier: StockSubscriptionTableViewCell.identifier, for: indexPath) as? StockSubscriptionTableViewCell,
              let info = model.getSubscriptionInfo(at: indexPath) else {
            return UITableViewCell()
        }
        
        let state = "申购状态"
        let firstSection = "\(info.stockName) - (\(info.stockCode))"
        let secondSection = "申购股数: \(info.stockCountString)"
        let thirdSection = "申购价: \(info.actualPrice)"
        let forthSection = "中签率: \(info.subscriptionRateString) %"
        
        cell.stateLabel.text = state
        cell.firstSectionLabel.text = firstSection
        cell.secondSectionLabel.text = secondSection
        cell.thirdSectionLabel.text = thirdSection
        cell.forthSectionLabel.text = forthSection
        
        return cell
    }
}

extension StockSubscriptionViewController: StockSubscriptionModelDelegate {
    
    func didRecieveList(_ subscriptionList: [StockSubscriptionInfo], error: Error?) {
        
        if let error = error {
            print("you got error during subscriptions request: \(error.localizedDescription)")
            return
        }
        
        tableView.reloadData()
    }
}

基本的 UI 大致如下

不过还差一点，因为这个申购资讯包含了一般人不会感兴趣的央债，市面上常用的下单软件，都会把央债去掉，而这一部分的职责，应该是 Model 要处理。当 Model 在接收到 StockSubscriptionManager 传过来的资料时，会 filter 掉央债，再通知 VC。

在 model 内加上一个 private func 做去除。股票代号的前几码是有意义的，举例来说 00 开头一定是 ETF，11 开头一定是水泥类股，12 开头一定是食品类股。

而央债的开头第一个字母是 A，我们可以用这个规则，把央债去掉。

private func filterNotAvailable(_ subscriptionList: [StockSubscriptionInfo]) -> [StockSubscriptionInfo] {
        
        let list = subscriptionList.filter { info in
            let code = info.stockCode
            let firstCharacter = code.first ?? "0"
            return firstCharacter != "A"
        }
        
        return list
    }

然後在收到申购列表後，进行清除，所以 func requestStockSubscription() 要改成这样。

func requestStockSubscription() {
        
        let year = 2021
        manager.requestStockSubscriptionInfo(year: year) { [weak self] subscriptionList, error in
            
            // 需要去掉中央债的资料
            self?.subscriptionList = self?.filterNotAvailable(subscriptionList) ?? []
            self?.delegate?.didRecieveList(subscriptionList, error: error)
        }
    }

这样，你的列表中就不会有央债的资料了