[Swift] バーコードをスキャンして取得したISBNから、本の画像等の情報を取得したい。

本のフリマアプリ「カウル」の類似アプリを作っています。

本のバーコードを読み取って、
本の詳細なデータ(本の画像とタイトルと値段と著者名等)を取得したいです。
作りたいものはこんな感じです。↓

バーコードを読み取って、ISBNを取得するということはできました。

本の情報を取得するにはどうしたらいいのでしょうか？

バーコードをスキャンして、ISBNを取得するまでのコードです。

Swift
1
2
3import UIKit
4import AVFoundation
5import AudioToolbox
6
7class ViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
8    
9    var captureDevice:AVCaptureDevice?
10    var videoPreviewLayer:AVCaptureVideoPreviewLayer?
11    var captureSession:AVCaptureSession?
12    
13    override func viewDidLoad() {
14        super.viewDidLoad()
15        
16        navigationItem.title = "Scanner"
17        view.backgroundColor = .white
18        
19        captureDevice = AVCaptureDevice.default(for: .video)
20        // Check if captureDevice returns a value and unwrap it
21        if let captureDevice = captureDevice {
22            
23            do {
24                let input = try AVCaptureDeviceInput(device: captureDevice)
25                
26                captureSession = AVCaptureSession()
27                guard let captureSession = captureSession else { return }
28                captureSession.addInput(input)
29                
30                let captureMetadataOutput = AVCaptureMetadataOutput()
31                captureSession.addOutput(captureMetadataOutput)
32                
33                captureMetadataOutput.setMetadataObjectsDelegate(self, queue: .main)
34                captureMetadataOutput.metadataObjectTypes = [.code128, .qr, .ean13,  .ean8, .code39] //AVMetadataObject.ObjectType
35                
36                captureSession.startRunning()
37                
38                videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
39                videoPreviewLayer?.videoGravity = .resizeAspectFill
40                videoPreviewLayer?.frame = view.layer.bounds
41                view.layer.addSublayer(videoPreviewLayer!)
42                
43            } catch {
44                print("Error Device Input")
45            }
46            
47        }
48        
49        view.addSubview(codeLabel)
50        codeLabel.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
51        codeLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
52        codeLabel.heightAnchor.constraint(equalToConstant: 50).isActive = true
53        codeLabel.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true
54        
55    }
56    
57    override func didReceiveMemoryWarning() {
58        super.didReceiveMemoryWarning()
59        // Dispose of any resources that can be recreated.
60    }
61    
62    let codeLabel:UILabel = {
63        let codeLabel = UILabel()
64        codeLabel.backgroundColor = .white
65        codeLabel.translatesAutoresizingMaskIntoConstraints = false
66        return codeLabel
67    }()
68    
69    let codeFrame:UIView = {
70        let codeFrame = UIView()
71        codeFrame.layer.borderColor = UIColor.green.cgColor
72        codeFrame.layer.borderWidth = 2
73        codeFrame.frame = CGRect.zero
74        codeFrame.translatesAutoresizingMaskIntoConstraints = false
75        return codeFrame
76    }()
77    
78    func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
79        
80        captureSession?.stopRunning()
81        guard let objects = metadataObjects as? [AVMetadataObject] else { return }
82        var detectionString: String? = nil
83        let barcodeTypes = [AVMetadataObject.ObjectType.ean8, AVMetadataObject.ObjectType.ean13]
84        for metadataObject in objects {
85            loop: for type in barcodeTypes {
86                guard metadataObject.type == type else { continue }
87                guard self.videoPreviewLayer?.transformedMetadataObject(for: metadataObject) is AVMetadataMachineReadableCodeObject else { continue }
88                if let object = metadataObject as? AVMetadataMachineReadableCodeObject {
89                    detectionString = object.stringValue
90                    break loop
91                }
92            }
93            var text = ""
94            guard let value = detectionString else { continue }
95            text += "読み込んだ値:\t(value)"
96            text += "\n"
97            guard let isbn = convartISBN(value: value) else { continue }
98            text += "ISBN:\t(isbn)"
99            print("text (text)")
100
101        }
102        
103        
104        
105    }
106    
107    
108    private func convartISBN(value: String) -> String? {
109        let v = NSString(string: value).longLongValue
110        let prefix: Int64 = Int64(v / 10000000000)
111        guard prefix == 978 || prefix == 979 else { return nil }
112        let isbn9: Int64 = (v % 10000000000) / 10
113        var sum: Int64 = 0
114        var tmpISBN = isbn9
115        /*
116         for var i = 10; i > 0 && tmpISBN > 0; i -= 1 {
117         let divisor: Int64 = Int64(pow(10, Double(i - 2)))
118         sum += (tmpISBN / divisor) * Int64(i)
119         tmpISBN %= divisor
120         }
121         */
122        
123        var i = 10
124        while i > 0 && tmpISBN > 0 {
125            let divisor: Int64 = Int64(pow(10, Double(i - 2)))
126            sum += (tmpISBN / divisor) * Int64(i)
127            tmpISBN %= divisor
128            i -= 1
129        }
130        
131        let checkdigit = 11 - (sum % 11)
132        return String(format: "%lld%@", isbn9, (checkdigit == 10) ? "X" : String(format: "%lld", checkdigit % 11))
133    }
134    
135}
136
137