Tutorial: Criar um aplicativo iOS que inicia a Leitura Avançada com o conteúdo de uma foto (Swift)Tutorial: Create an iOS app that launches the Immersive Reader with content from a photo (Swift)

A Leitura Avançada é uma ferramenta projetada de forma inclusiva que implementa técnicas comprovadas para melhorar a compreensão da leitura.The Immersive Reader is an inclusively designed tool that implements proven techniques to improve reading comprehension.

A API de Leitura de Serviços Cognitivos de Pesquisa Visual Computacional detecta o conteúdo de texto em uma imagem usando os modelos de reconhecimento mais recentes da Microsoft e converte o texto identificado em um fluxo de caracteres legível por computador.The Computer Vision Cognitive Services Read API detects text content in an image using Microsoft's latest recognition models and converts the identified text into a machine-readable character stream.

Neste tutorial, você criará um aplicativo iOS do zero e integrará a API de Leitura e a Leitura Avançada usando o SDK de Leitura Avançada.In this tutorial, you will build an iOS app from scratch and integrate the Read API, and the Immersive Reader by using the Immersive Reader SDK. Um exemplo de funcionamento completo deste tutorial está disponível aqui.A full working sample of this tutorial is available here.

Se você não tiver uma assinatura do Azure, crie uma conta gratuita antes de começar.If you don't have an Azure subscription, create a free account before you begin.

Pré-requisitosPrerequisites

Criar um projeto do XcodeCreate an Xcode project

Criar um projeto no Xcode.Create a new project in Xcode.

Novo Projeto

Escolha Aplicativo de Modo de Exibição Único.Choose Single View App.

Novo Aplicativo de Modo de Exibição Único

Obter o SDK CocoaPodGet the SDK CocoaPod

A maneira mais fácil de usar o SDK de Leitura Avançada é por meio do CocoaPods.The easiest way to use the Immersive Reader SDK is via CocoaPods. Para instalar por meio do Cocoapods:To install via Cocoapods:

  1. Instalar CocoaPods – Siga o guia de introdução para instalar o Cocoapods.Install CocoaPods - Follow the getting started guide to install Cocoapods.
  2. Crie um Podfile executando pod init no diretório raiz do projeto Xcode.Create a Podfile by running pod init in your Xcode project's root directory.
  3. Adicione o CocoaPod ao seu Podfile adicionando pod 'immersive-reader-sdk', :path => 'https://github.com/microsoft/immersive-reader-sdk/tree/master/iOS/immersive-reader-sdk'.Add the CocoaPod to your Podfile by adding pod 'immersive-reader-sdk', :path => 'https://github.com/microsoft/immersive-reader-sdk/tree/master/iOS/immersive-reader-sdk'. Seu Podfile deve ser semelhante ao seguinte, com o nome do destino substituindo picture-to-immersive-reader-swift:Your Podfile should look like the following, with your target's name replacing picture-to-immersive-reader-swift:
 platform :ios, '9.0'

 target 'picture-to-immersive-reader-swift' do
 use_frameworks!
 # Pods for picture-to-immersive-reader-swift
 pod 'immersive-reader-sdk', :path => 'https://github.com/microsoft/immersive-reader-sdk/tree/master/iOS/immersive-reader-sdk'
 end
  1. No terminal, no diretório do seu projeto Xcode, execute o comando pod install para instalar o pod do SDK de Leitura Avançada.In the terminal, in the directory of your Xcode project, run the command pod install to install the Immersive Reader SDK pod.
  2. Adicione import immersive_reader_sdk a todos os arquivos que precisam referenciar o SDK.Add import immersive_reader_sdk to all files that need to reference the SDK.
  3. Abra o projeto abrindo o arquivo .xcworkspace, e não o arquivo .xcodeproj.Ensure to open the project by opening the .xcworkspace file and not the .xcodeproj file.

Adquirir um token de autenticação do Azure ADAcquire an Azure AD authentication token

Você precisará de alguns valores da etapa de pré-requisito de configuração da autenticação do Azure AD acima para esta parte.You need some values from the Azure AD authentication configuration prerequisite step above for this part. Veja novamente o arquivo de texto que você salvou dessa sessão.Refer back to the text file you saved of that session.

TenantId     => Azure subscription TenantId
ClientId     => Azure AD ApplicationId
ClientSecret => Azure AD Application Service Principal password
Subdomain    => Immersive Reader resource subdomain (resource 'Name' if the resource was created in the Azure portal, or 'CustomSubDomain' option if the resource was created with Azure CLI Powershell. Check the Azure portal for the subdomain on the Endpoint in the resource Overview page, for example, 'https://[SUBDOMAIN].cognitiveservices.azure.com/')

Na pasta do projeto principal, que contém o arquivo ViewController.swift, crie um arquivo de classe Swift chamado Constants.swift.In the main project folder, which contains the ViewController.swift file, create a Swift class file called Constants.swift. Substitua a classe pelo código a seguir, adicionando em seus valores quando aplicável.Replace the class with the following code, adding in your values where applicable. Mantenha esse arquivo como um arquivo local que só existe em seu computador e não faça commit desse arquivo no controle do código-fonte, pois ele contém segredos que não devem ser tornados públicos.Keep this file as a local file that only exists on your machine and be sure not to commit this file into source control, as it contains secrets that should not be made public. É recomendável que você não mantenha segredos em seu aplicativo.It is recommended that you do not keep secrets in your app. Em vez disso, recomendamos usar um serviço de back-end para obter o token, em que os segredos podem ser mantidos fora do aplicativo e do dispositivo.Instead, we recommend using a backend service to obtain the token, where the secrets can be kept outside of the app and off of the device. O ponto de extremidade da API de back-end deve ser protegido por alguma forma de autenticação (por exemplo, OAuth) para impedir que usuários não autorizados obtenham tokens para usar em seu serviço de Leitura Avançada e cobrança; esse trabalho está além do escopo deste tutorial.The backend API endpoint should be secured behind some form of authentication (for example, OAuth) to prevent unauthorized users from obtaining tokens to use against your Immersive Reader service and billing; that work is beyond the scope of this tutorial.

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

import Foundation

// This file contains secrets. Do not check this file into source control. Keep this file as a local file that only exists on your development machine.

public struct Constants {
    static let tenantId: String = "<YOUR_TENANT_ID>"
    static let clientId: String = "<YOUR_CLIENT_ID>"
    static let clientSecret: String = "<YOUR_CLIENT_SECRET>"
    static let subdomain: String = "<YOUR_SUBDOMAIN>"
    
    static let computerVisionSubscriptionKey: String = "<YOUR_SUBSCRIPTION_KEY>"
    static let computerVisionEndPoint: String = "<YOUR_ENDPOINT>"
}

Configurar o aplicativo para ser executado sem um storyboardSet up the app to run without a storyboard

Abra AppDelegate.swift e substitua o arquivo pelo código a seguir.Open AppDelegate.swift and replace the file with the following code.

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    
    var window: UIWindow?
    
    var navigationController: UINavigationController?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        
        window = UIWindow(frame: UIScreen.main.bounds)
        
        if let window = window {
            let mainViewController = PictureLaunchViewController()
            navigationController = UINavigationController(rootViewController: mainViewController)
            window.rootViewController = navigationController
            window.makeKeyAndVisible()
        }
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    }

}

Adicionar funcionalidade para tirar e carregar fotosAdd functionality for taking and uploading photos

Renomeie ViewController.swift para PictureLaunchViewController.swift e substitua o arquivo pelo código a seguir.Rename ViewController.swift to PictureLaunchViewController.swift and replace the file with the following code.

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

import UIKit
import immersive_reader_sdk

class PictureLaunchViewController: UIViewController, UINavigationControllerDelegate, UIImagePickerControllerDelegate {

    private var photoButton: UIButton!
    private var cameraButton: UIButton!
    private var titleText: UILabel!
    private var bodyText: UILabel!
    private var sampleContent: Content!
    private var sampleChunk: Chunk!
    private var sampleOptions: Options!
    private var imagePicker: UIImagePickerController!
    private var spinner: UIActivityIndicatorView!
    private var activityIndicatorBackground: UIView!
    private var textURL = "vision/v2.0/read/core/asyncBatchAnalyze";
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = .white
        
        titleText = UILabel()
        titleText.text = "Picture to Immersive Reader with OCR"
        titleText.font = UIFont.boldSystemFont(ofSize: 32)
        titleText.textAlignment = .center
        titleText.lineBreakMode = .byWordWrapping
        titleText.numberOfLines = 0
        view.addSubview(titleText)
        
        bodyText = UILabel()
        bodyText.text = "Capture or upload a photo of handprinted text on a piece of paper, handwriting, typed text, text on a computer screen, writing on a white board and many more, and watch it be presented to you in the Immersive Reader!"
        bodyText.font = UIFont.systemFont(ofSize: 18)
        bodyText.lineBreakMode = .byWordWrapping
        bodyText.numberOfLines = 0
        let screenSize = self.view.frame.height
        if screenSize <= 667 {
            // Font size for smaller iPhones.
            bodyText.font = bodyText.font.withSize(16)

        } else if screenSize <= 812.0 {
            // Font size for medium iPhones.
            bodyText.font = bodyText.font.withSize(18)
            
        } else if screenSize <= 896  {
            // Font size for larger iPhones.
            bodyText.font = bodyText.font.withSize(20)
            
        } else {
            // Font size for iPads.
            bodyText.font = bodyText.font.withSize(26)
        }
        view.addSubview(bodyText)
        
        photoButton = UIButton()
        photoButton.backgroundColor = .darkGray
        photoButton.contentEdgeInsets = UIEdgeInsets(top: 10, left: 5, bottom: 10, right: 5)
        photoButton.layer.cornerRadius = 5
        photoButton.setTitleColor(.white, for: .normal)
        photoButton.setTitle("Choose Photo from Library", for: .normal)
        photoButton.titleLabel?.font = UIFont.systemFont(ofSize: 18, weight: .bold)
        photoButton.addTarget(self, action: #selector(selectPhotoButton(sender:)), for: .touchUpInside)
        view.addSubview(photoButton)
        
        cameraButton = UIButton()
        cameraButton.backgroundColor = .darkGray
        cameraButton.contentEdgeInsets = UIEdgeInsets(top: 10, left: 5, bottom: 10, right: 5)
        cameraButton.layer.cornerRadius = 5
        cameraButton.setTitleColor(.white, for: .normal)
        cameraButton.setTitle("Take Photo", for: .normal)
        cameraButton.titleLabel?.font = UIFont.systemFont(ofSize: 18, weight: .bold)
        cameraButton.addTarget(self, action: #selector(takePhotoButton(sender:)), for: .touchUpInside)
        view.addSubview(cameraButton)
        
        activityIndicatorBackground = UIView()
        activityIndicatorBackground.backgroundColor = UIColor.black
        activityIndicatorBackground.alpha = 0
        view.addSubview(activityIndicatorBackground)
        view.bringSubviewToFront(_: activityIndicatorBackground)
        
        spinner = UIActivityIndicatorView(style: .whiteLarge)
        view.addSubview(spinner)
        
        let layoutGuide = view.safeAreaLayoutGuide
        
        titleText.translatesAutoresizingMaskIntoConstraints = false
        titleText.topAnchor.constraint(equalTo: layoutGuide.topAnchor, constant: 25).isActive = true
        titleText.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor, constant: 20).isActive = true
        titleText.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor, constant: -20).isActive = true
        
        bodyText.translatesAutoresizingMaskIntoConstraints = false
        bodyText.topAnchor.constraint(equalTo: titleText.bottomAnchor, constant: 35).isActive = true
        bodyText.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor, constant: 20).isActive = true
        bodyText.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor, constant: -20).isActive = true

        cameraButton.translatesAutoresizingMaskIntoConstraints = false
        if screenSize > 896  {
            // Constraints for iPads.
            cameraButton.heightAnchor.constraint(equalToConstant: 150).isActive = true
            cameraButton.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor, constant: 60).isActive = true
            cameraButton.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor, constant: -60).isActive = true
            cameraButton.topAnchor.constraint(equalTo: bodyText.bottomAnchor, constant: 150).isActive = true
        } else {
            // Constraints for iPhones.
            cameraButton.heightAnchor.constraint(equalToConstant: 100).isActive = true
            cameraButton.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor, constant: 30).isActive = true
            cameraButton.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor, constant: -30).isActive = true
            cameraButton.topAnchor.constraint(equalTo: bodyText.bottomAnchor, constant: 100).isActive = true
        }
        cameraButton.bottomAnchor.constraint(equalTo: photoButton.topAnchor, constant: -40).isActive = true
        
        photoButton.translatesAutoresizingMaskIntoConstraints = false
        if screenSize > 896  {
            // Constraints for iPads.
            photoButton.heightAnchor.constraint(equalToConstant: 150).isActive = true
            photoButton.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor, constant: 60).isActive = true
            photoButton.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor, constant: -60).isActive = true
        } else {
            // Constraints for iPhones.
            photoButton.heightAnchor.constraint(equalToConstant: 100).isActive = true
            photoButton.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor, constant: 30).isActive = true
            photoButton.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor, constant: -30).isActive = true
        }
        
        spinner.translatesAutoresizingMaskIntoConstraints = false
        spinner.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        spinner.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
        
        activityIndicatorBackground.translatesAutoresizingMaskIntoConstraints = false
        activityIndicatorBackground.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
        activityIndicatorBackground.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true
        activityIndicatorBackground.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
        activityIndicatorBackground.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
        
        // Create content and options.
        sampleChunk = Chunk(content: bodyText.text!, lang: nil, mimeType: nil)
        sampleContent = Content(title: titleText.text!, chunks: [sampleChunk])
        sampleOptions = Options(uiLang: nil, timeout: nil, uiZIndex: nil)
        
    }
    
    @IBAction func selectPhotoButton(sender: AnyObject) {
            // Launch the photo picker.
            imagePicker =  UIImagePickerController()
            imagePicker.delegate = self
            self.imagePicker.sourceType = .photoLibrary
            self.imagePicker.allowsEditing = true
            self.present(self.imagePicker, animated: true, completion: nil)
            self.photoButton.isEnabled = true
        
    }
    
    @IBAction func takePhotoButton(sender: AnyObject) {
        if !UIImagePickerController.isSourceTypeAvailable(.camera) {
            // If there is no camera on the device, disable the button
            self.cameraButton.backgroundColor = .gray
            self.cameraButton.isEnabled = true
            
        } else {
            // Launch the camera.
            imagePicker =  UIImagePickerController()
            imagePicker.delegate = self
            self.imagePicker.sourceType = .camera
            self.present(self.imagePicker, animated: true, completion: nil)
            self.cameraButton.isEnabled = true
        }
        
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        imagePicker.dismiss(animated: true, completion: nil)
        photoButton.isEnabled = false
        cameraButton.isEnabled = false
        self.spinner.startAnimating()
        activityIndicatorBackground.alpha = 0.6
        
        // Retrieve the image.
        let image = (info[.originalImage] as? UIImage)!
        
        // Retrieve the byte array from image.
        let imageByteArray = image.jpegData(compressionQuality: 1.0)
        
        // Call the getTextFromImage function passing in the image the user takes or chooses.
        getTextFromImage(subscriptionKey: Constants.computerVisionSubscriptionKey, getTextUrl: Constants.computerVisionEndPoint + textURL, pngImage: imageByteArray!, onSuccess: { cognitiveText in
            print("cognitive text is: \(cognitiveText)")
            DispatchQueue.main.async {
                self.photoButton.isEnabled = true
                self.cameraButton.isEnabled = true
            }
            
            // Create content and options with the text from the image.
            let sampleImageChunk = Chunk(content: cognitiveText, lang: nil, mimeType: nil)
            let sampleImageContent = Content(title: "Text from image", chunks: [sampleImageChunk])
            let sampleImageOptions = Options(uiLang: nil, timeout: nil, uiZIndex: nil)
            
            // Callback to get token for Immersive Reader.
            self.getToken(onSuccess: {cognitiveToken in
                
                DispatchQueue.main.async {
                    
                    launchImmersiveReader(navController: self.navigationController!, token: cognitiveToken, subdomain: Constants.subdomain, content: sampleImageContent, options: sampleImageOptions, onSuccess: {
                        self.spinner.stopAnimating()
                        self.activityIndicatorBackground.alpha = 0
                        self.photoButton.isEnabled = true
                        self.cameraButton.isEnabled = true
                        
                    }, onFailure: { error in
                        print("An error occured launching the Immersive Reader: \(error)")
                        self.spinner.stopAnimating()
                        self.activityIndicatorBackground.alpha = 0
                        self.photoButton.isEnabled = true
                        self.cameraButton.isEnabled = true
                        
                    })
                }

            }, onFailure: { error in
                DispatchQueue.main.async {
                    self.photoButton.isEnabled = true
                    self.cameraButton.isEnabled = true
                    
                }
                print("An error occured retrieving the token: \(error)")
            })
            
        }, onFailure: { error in
            DispatchQueue.main.async {
                self.photoButton.isEnabled = true
                self.cameraButton.isEnabled = true
            }
            
        })
        
    }
    
    /// Retrieves the token for the Immersive Reader using Azure Active Directory authentication
    ///
    /// - Parameters:
    ///     -onSuccess: A closure that gets called when the token is successfully recieved using Azure Active Directory authentication.
    ///     -theToken: The token for the Immersive Reader recieved using Azure Active Directory authentication.
    ///     -onFailure: A closure that gets called when the token fails to be obtained from the Azure Active Directory Authentication.
    ///     -theError: The error that occured when the token fails to be obtained from the Azure Active Directory Authentication.
    func getToken(onSuccess: @escaping (_ theToken: String) -> Void, onFailure: @escaping ( _ theError: String) -> Void) {
        
        let tokenForm = "grant_type=client_credentials&resource=https://cognitiveservices.azure.com/&client_id=" + Constants.clientId + "&client_secret=" + Constants.clientSecret
        let tokenUrl = "https://login.windows.net/" + Constants.tenantId + "/oauth2/token"
        
        var responseTokenString: String = "0"
        
        let url = URL(string: tokenUrl)!
        var request = URLRequest(url: url)
        request.httpBody = tokenForm.data(using: .utf8)
        request.httpMethod = "POST"
        
        let task = URLSession.shared.dataTask(with: request) { data, response, error in
            guard let data = data,
                let response = response as? HTTPURLResponse,
                // Check for networking errors.
                error == nil else {
                    print("error", error ?? "Unknown error")
                    onFailure("Error")
                    return
            }
            
            // Check for http errors.
            guard (200 ... 299) ~= response.statusCode else {
                print("statusCode should be 2xx, but is \(response.statusCode)")
                print("response = \(response)")
                onFailure(String(response.statusCode))
                return
            }
            
            let responseString = String(data: data, encoding: .utf8)
            print("responseString = \(String(describing: responseString!))")
            
            let jsonResponse = try? JSONSerialization.jsonObject(with: data, options: [])
            guard let jsonDictonary = jsonResponse as? [String: Any] else {
                onFailure("Error parsing JSON response.")
                return
            }
            guard let responseToken = jsonDictonary["access_token"] as? String else {
                onFailure("Error retrieving token from JSON response.")
                return
            }
            responseTokenString = responseToken
            onSuccess(responseTokenString)
        }
        
        task.resume()
    }
    
    /// Returns the text string after it has been extracted from an Image input.
    ///
    /// - Parameters:
    ///     -subscriptionKey: The Azure subscription key.
    ///     -pngImage: Image data in PNG format.
    /// - Returns: a string of text representing the
    func getTextFromImage(subscriptionKey: String, getTextUrl: String, pngImage: Data, onSuccess: @escaping (_ theToken: String) -> Void, onFailure: @escaping ( _ theError: String) -> Void) {
        
        let url = URL(string: getTextUrl)!
        var request = URLRequest(url: url)
        request.setValue(subscriptionKey, forHTTPHeaderField: "Ocp-Apim-Subscription-Key")
        request.setValue("application/octet-stream", forHTTPHeaderField: "Content-Type")
        
        // Two REST API calls are required to extract text. The first call is to submit the image for processing, and the next call is to retrieve the text found in the image.
        
        // Set the body to the image in byte array format.
        request.httpBody = pngImage
        
        request.httpMethod = "POST"
        
        let task = URLSession.shared.dataTask(with: request) { data, response, error in
            guard let data = data,
                let response = response as? HTTPURLResponse,
                // Check for networking errors.
                error == nil else {
                    print("error", error ?? "Unknown error")
                    onFailure("Error")
                    return
            }
            
            // Check for http errors.
            guard (200 ... 299) ~= response.statusCode else {
                print("statusCode should be 2xx, but is \(response.statusCode)")
                print("response = \(response)")
                onFailure(String(response.statusCode))
                return
            }
            
            let responseString = String(data: data, encoding: .utf8)
            print("responseString = \(String(describing: responseString!))")
            
            // Send the second call to the API. The first API call returns operationLocation which stores the URI for the second REST API call.
            let operationLocation = response.allHeaderFields["Operation-Location"] as? String
            
            if (operationLocation == nil) {
                print("Error retrieving operation location")
                return
            }
            
            // Wait 10 seconds for text recognition to be available as suggested by the Text API documentation.
            print("Text submitted. Waiting 10 seconds to retrieve the recognized text.")
            sleep(10)
            
            // HTTP GET request with the operationLocation url to retrieve the text.
            let getTextUrl = URL(string: operationLocation!)!
            var getTextRequest = URLRequest(url: getTextUrl)
            getTextRequest.setValue(subscriptionKey, forHTTPHeaderField: "Ocp-Apim-Subscription-Key")
            getTextRequest.httpMethod = "GET"
            
            // Send the GET request to retrieve the text.
            let taskGetText = URLSession.shared.dataTask(with: getTextRequest) { data, response, error in
                guard let data = data,
                    let response = response as? HTTPURLResponse,
                    // Check for networking errors.
                    error == nil else {
                        print("error", error ?? "Unknown error")
                        onFailure("Error")
                        return
                }
                
                // Check for http errors.
                guard (200 ... 299) ~= response.statusCode else {
                    print("statusCode should be 2xx, but is \(response.statusCode)")
                    print("response = \(response)")
                    onFailure(String(response.statusCode))
                    return
                }
                
                // Decode the JSON data into an object.
                let customDecoding = try! JSONDecoder().decode(TextApiResponse.self, from: data)
                
                // Loop through the lines to get all lines of text and concatenate them together.
                var textFromImage = ""
                for textLine in customDecoding.recognitionResults[0].lines {
                    textFromImage = textFromImage + textLine.text + " "
                }
                
                onSuccess(textFromImage)
            }
            taskGetText.resume()

        }
        
        task.resume()
    }
    
    // Structs used for decoding the Text API JSON response.
    struct TextApiResponse: Codable {
        let status: String
        let recognitionResults: [RecognitionResult]
    }

    struct RecognitionResult: Codable {
        let page: Int
        let clockwiseOrientation: Double
        let width, height: Int
        let unit: String
        let lines: [Line]
    }

    struct Line: Codable {
        let boundingBox: [Int]
        let text: String
        let words: [Word]
    }

    struct Word: Codable {
        let boundingBox: [Int]
        let text: String
        let confidence: String?
    }
    
}

Compilar e executar o aplicativoBuild and run the app

Defina o esquema de arquivo no Xcode selecionando um simulador ou um destino do dispositivo.Set the archive scheme in Xcode by selecting a simulator or device target. Esquema de arquivoArchive scheme
Selecionar destinoSelect Target

No Xcode, pressione Ctrl + R ou clique no botão reproduzir para executar o projeto e o aplicativo deverá ser iniciado no simulador ou dispositivo especificado.In Xcode, press Ctrl + R or click on the play button to run the project and the app should launch on the specified simulator or device.

Em seu aplicativo, você deverá ver:In your app, you should see:

Aplicativo de exemplo

Dentro do aplicativo, tire ou carregue uma foto de texto pressionando o botão 'Tirar Foto' ou 'Escolher Foto da Biblioteca' e a Leitura Avançada será iniciada exibindo o texto da foto.Inside the app, take or upload a photo of text by pressing the 'Take Photo' button or 'Choose Photo from Library' button and the Immersive Reader will then launch displaying the text from the photo.

Leitura Avançada

Próximas etapasNext steps