Quickstart(web view)

Android(JavaScript)

Using JavaScript SDK within the Android WebView requires some extra steps.

๐Ÿšง

JavaScript SDK does not provide a push notification.

Use Android SDK instead of the JavaScript SDK to support a push notification. See the instructions of Android(SDK) section to follow the best practices.

Allow new tab

To allow new tab in an Android WebView, some additional configurations are required.

webChromeClient = object : WebChromeClient() {
    override fun onCreateWindow(
        view: WebView?,
        isDialog: Boolean,
        isUserGesture: Boolean,
        resultMsg: Message?
    ): Boolean {
        // intercept new window
        val transport = resultMsg?.obj as? WebView.WebViewTransport
        val newWebView = WebView(this@WebViewActivity)

        view?.addView(newWebView)
        transport?.webView = newWebView
        resultMsg?.sendToTarget()

        newWebView.webViewClient = object : WebViewClient() {
            // handle url navigating and create new activity
            override fun shouldOverrideUrlLoading(
                    view: WebView,
                    url: String
            ): Boolean {
                return when {
                    url.startsWith("tel:") -> {
                        val intent = Intent(Intent.ACTION_DIAL, Uri.parse(url))
                        startActivity(intent)
                        true
                    }
                    url.startsWith("mailto:") -> {
                        val intent = Intent(Intent.ACTION_SENDTO, Uri.parse(url))
                        startActivity(intent)
                        true
                    }
                    else -> {
                        Intent(view.context, WebViewActivity::class.java)
                            .apply { putExtra("url", url) }
                            .also { intent -> startActivity(intent) }
                        true
                    }
                }
            }
        }

        return true
    }
}

Uploading files

If you are using Android WebView, users will not be able to launch a file chooser when they click the attachment button to send files. The problem is that WebView does not implement default file choosing behavior, so we must manually define how we handle the users' actions. With our simple solution and snippets, you will only take a minimal effort on integrating JavaScript SDK with your mobile application.

๐Ÿ“˜

We highly recommend using theย Android SDKย for those who are looking for effortless and straightforward experiences on mobile devices.

  1. Allow WebView to access files and setย WebChromeClientย to get notified when the user wants to open the file chooser.
yourWebViewInstance.apply {
    settings.apply {
        // -- your other WebView options --

        // add this line to make WebView to access file system
        allowFileAccess = true
    }

    webChromeClient = object : WebChromeClient() {
        override fun onShowFileChooser(
                webView: WebView,
                filePathCallback: ValueCallback<Array<Uri>>,
                fileChooserParams: FileChooserParams
        ): Boolean {
                // -- snip --
        }
}
  1. Copy our code ofย WebViewAttachmentModuleย class that is responsible for handling file chooser callbacks. Note that you may change the snippet as it is provided to help you write code faster.

๐Ÿšง

Make sure to return true from onShowFileChooser

The WebChromeClient does not allow filePathCallback to be invoked if onShowFileChooser returns false. As the module always calls the callback when an intent for a file chooser is created, make sure to call getIntentChooser only if onShowFileChooser returns true.

class WebViewAttachmentModule {

    private var filePathCallback: ValueCallback<Array<Uri>>? = null

    fun getIntentChooser(filePathCallback: ValueCallback<Array<Uri>>, acceptTypes: Array<String>): Intent {
        // init filePathCallback
        this.filePathCallback?.onReceiveValue(null)
        this.filePathCallback = filePathCallback

        return Intent(Intent.ACTION_GET_CONTENT).apply {
            addCategory(Intent.CATEGORY_OPENABLE)
            type = "*/*"
            putExtra(Intent.EXTRA_MIME_TYPES, getMimeTypesFromAcceptTypes(acceptTypes))
        }
    }

    // handle onActivityResult process in activity
    fun handleResult(requestCode: Int, resultCode: Int, data: Intent?) {
        val uri = data?.data
        if (requestCode == WEB_VIEW_FILE_UPLOAD_REQUEST_CODE && resultCode == AppCompatActivity.RESULT_OK && uri != null) {
            filePathCallback?.onReceiveValue(arrayOf(uri))
        } else {
            filePathCallback?.onReceiveValue(null)
        }
        filePathCallback = null
    }

    private fun getMimeTypesFromAcceptTypes(acceptTypes: Array<String>): Array<String> {
        return (acceptTypes
                .mapNotNull { acceptType ->
                    when {
                        // Seperate case of extensions and MIME Type
                        acceptType.startsWith(".") -> MimeTypeMap.getSingleton().getMimeTypeFromExtension(acceptType.substring(1))
                        else -> acceptType
                    }
                }
                // setting "*/*" when acceptType is not exist
                .filter { it.isNotBlank() }
                .takeIf { it.isNotEmpty() }
                ?: listOf("*/*"))
                .toTypedArray()
    }
}

File Download

Please be aware that Android WebView does not natively support downloading files such as photos or videos. The following code demonstrates how to intercept URL requests and download files when they are identified as images or videos, specifically from Channel Talk.

  1. Refer to the following to write a listener responsible for handling image / video downloads.
class WebViewDownloadListener(
        private val context: Context,
) : DownloadListener {
    override fun onDownloadStart(url: String?, userAgent: String?, contentDisposition: String?, mimetype: String?, contentLength: Long) {
        val uri = Uri.parse(url)

        val fileName = URLUtil.guessFileName(url, contentDisposition, mimetype)
        val request = DownloadManager.Request(uri)

        val cookie = CookieManager.getInstance().getCookie(url)
        request.addRequestHeader("Cookie", cookie)
        request.addRequestHeader("User-Agent", userAgent)

        request.setTitle(fileName)

        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName)
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED)

        val downloadManager = context.getSystemService(Context.DOWNLOAD_SERVICE) as? DownloadManager

        downloadManager?.enqueue(request)
    }
}
  1. Apply the written listener to the activity. An example is shown below.
yourWebViewInstance.setDownloadListener(WebViewDownloadListener(context))

Usage sample

๐Ÿšง

Please change the following sample code to fit your requirements.

class WebViewActivity : AppCompatActivity() {
  
    private val attachmentModule = WebViewAttachmentModule()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_web_view)

        webview.webViewClient = WebViewClient()

        val url = intent.getStringExtra("url") ?: SOME_DEFAULT_URL

        webview.apply {
            // handle file downloads
            setDownloadListener(WebViewDownloadListener(context))

            settings.apply {
                // WebView settings
                javaScriptEnabled = true
                domStorageEnabled = true
                useWideViewPort = true
                allowFileAccess = true

                setSupportMultipleWindows(true)
                javaScriptCanOpenWindowsAutomatically = true
            }

            webChromeClient = object : WebChromeClient() {
                // handle file uploads
                override fun onShowFileChooser(
                        webView: WebView,
                        filePathCallback: ValueCallback<Array<Uri>>,
                        fileChooserParams: FileChooserParams
                ): Boolean {
                    startActivityForResult(
                            attachmentModule.getIntentChooser(
                                    filePathCallback,
                                    fileChooserParams.acceptTypes,
                            ),
                            Const.WEB_VIEW_FILE_UPLOAD_REQUEST_CODE,
                    ) // Call getIntentChooser() only if the function returns true.
                    return true
                }
              
                override fun onCreateWindow(
                    view: WebView?,
                    isDialog: Boolean,
                    isUserGesture: Boolean,
                    resultMsg: Message?
                ): Boolean {
                    // intercept new window
                    val transport = resultMsg?.obj as? WebView.WebViewTransport
                    val newWebView = WebView(this@WebViewActivity)

                    view?.addView(newWebView)
                    transport?.webView = newWebView
                    resultMsg?.sendToTarget()

                    newWebView.webViewClient = object : WebViewClient() {
                        // handle URL navigation
                        override fun shouldOverrideUrlLoading(
                                view: WebView,
                                url: String
                        ): Boolean {
                            return when {
                                url.startsWith("tel:") -> {
                                    val intent = Intent(Intent.ACTION_DIAL, Uri.parse(url))
                                    startActivity(intent)
                                    true
                                }
                                url.startsWith("mailto:") -> {
                                    val intent = Intent(Intent.ACTION_SENDTO, Uri.parse(url))
                                    startActivity(intent)
                                    true
                                }
                                else -> {
                                    Intent(view.context, WebViewActivity::class.java)
                                        .apply { putExtra("url", url) }
                                        .also { intent -> startActivity(intent) }
                                    true
                                }
                            }
                        }
                    }

                    return true
                }
            }
        }

        webview.loadUrl(url)
    }
  
    // handle file upload
    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        attachmentModule.handleResult(requestCode, resultCode, data)

        super.onActivityResult(requestCode, resultCode, data)
    }
}

Android(SDK)

Instead of embedding JavaScript SDK to the WebView, you might decide to use Android SDK along with the WebView. A major reason for the decision is when you need to send a push notification. See how to get started with the Android SDK and enabling the push notification.

โ—๏ธ

Hide redundant Channel SDK UI.

When using both JavaScript SDK and Android SDK, set hideChannelButtonOnBoot and hidePopup=true in Boot Option of JavaScript SDK to hide the Channel button and popups. Android SDK and JavaScript SDK might duplicate Channel SDK UI.

To allow Android SDK to know the current URL of the WebView, call setPage with appropriate data. Event tracking and workflow targeting will work smoothly with the information.

class WebViewActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
 
        ...

        webview.apply {
            settings.apply {
                // settings
            }

            webViewClient = object : WebViewClient() {
                override fun onPageStarted(view: WebView, url: String, favicon: Bitmap?) {
                    // set current page to SDK
                    ChannelIO.setPage(url)
                }
            }
        }

        webview.loadUrl(url)
    }
}

iOS

This section describes how to use the JavaScript SDK installed on the mobile web in an iOS WebView environment.

๐Ÿ“˜

Ensure filled out your info.plist

Before you get started, refer to this After Installation to make sure you've filled out your Info.plist with a description of the permissions you use.

๐Ÿšง

Push Notification doesnโ€™t work if you are using only JavaScript.

To use the push notification, Refers ChannelIO iOS SDK

The Following Example loads a page with a URL in your YOUR_WEB_URL on any WebView ViewController.

import UIKit
import WebKit
import Photos

class ViewController: UIViewController, WKNavigationDelegate, WKUIDelegate {
  enum FileFormat: String {
    case image
    case video
    case file
    
    init(rawValue: String) {
      switch rawValue {
      case "image": self = .image
      case "video": self = .video
      default: self = .file
      }
    }
  }
  
  var webView: WKWebView!
  var url: String = "YOUR_WEB_URL"
    
  private let indicator: UIActivityIndicatorView = {
    $0.style = .medium
    $0.startAnimating()
    $0.isHidden = true
    $0.translatesAutoresizingMaskIntoConstraints = false
    return $0
  }(UIActivityIndicatorView(style: .large))
  
  override func loadView() {
    let config = WKWebViewConfiguration()
    config.allowsInlineMediaPlayback = true  // # 1. modify to true inlineMediaPlay option
    
    webView = WKWebView(frame: .zero, configuration: config)
    webView.uiDelegate = self
    webView.navigationDelegate = self

    view = webView  
  }
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    let myURL = URL(string:self.url)
    let myRequest = URLRequest(url: self.myURL!)
    self.webView.load(myRequest)
    self.setupActivityIndicator()

  }
  
  // #2. handle target_blank type route
  func webView(
    _ webView: WKWebView, 
    createWebViewWith configuration: WKWebViewConfiguration, 
    for navigationAction: WKNavigationAction, 
    windowFeatures: WKWindowFeatures) -> WKWebView? {
    if navigationAction.targetFrame == nil {
      webView.load(navigationAction.request)
    }
    return nil
  }
  
  // # 3. Downloadin File, Image or Video
    guard
      let response = navigationResponse.response as? HTTPURLResponse,
      let url = response.url,
      url.pathComponents.contains(where: { $0 == "pri-file"}),
      response.statusCode == 200,
      let mimeType = response.mimeType?.split(separator: "/").first,
      let contentDisposition = response.allHeaderFields["Content-Disposition"] as? String,
      contentDisposition.contains("attachment;")
    else {
      decisionHandler(.allow)
      return
    }
    
    let fileExtension = contentDisposition.components(separatedBy: ".").last ?? ""
    let fileFormat = FileFormat(rawValue: String(mimeType))
    
    self.downloadFile(from: url, fileExtension: String(fileExtension)) { [weak self] result in
      switch result {
      case .success(let url):
        switch fileFormat {
        case .image, .video:
          self?.saveToPhotoLibrary(fileURL: url, format: fileFormat) { [weak self] _ in
            self?.hideActivityIndicator()
          }
        case .file:
          DispatchQueue.main.async { [weak self] in
            let controller = UIActivityViewController(
              activityItems: [url],
              applicationActivities: nil
            )
            self?.present(controller, animated: true)
          }
        }
      case .failure(let error):
        print("file download was ended with failure. \(error.localizedDescription)")
      }
      
      if #available(iOS 14.5, *) {
        decisionHandler(.download)
      } else {
        decisionHandler(.allow)
      }
    }
  }
}

extension ViewController {
  private func setupActivityIndicator() {
    self.view.addSubview(self.indicator)
    
    NSLayoutConstraint.activate([
      self.indicator.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
      self.indicator.centerYAnchor.constraint(equalTo: self.view.centerYAnchor),
    ])
  }
  
  private func showActivityIndicator() {
    DispatchQueue.main.async {
      self.indicator.isHidden = false
      self.indicator.startAnimating()
    }
  }
  
  private func hideActivityIndicator() {
    DispatchQueue.main.async {
      self.indicator.isHidden = true
      self.indicator.stopAnimating()
    }
  }
  
  private func downloadFile(
    from url: URL,
    fileExtension: String,
    completion: @escaping (Result<URL, Error>) -> ()
  ) {
    URLSession.shared.downloadTask(with: url) { location, response, error in
      guard let location, error == nil else {
        completion(.failure(error ?? NSError(domain: "failed to download.", code: -2) ))
        return
      }

      let fileManager = FileManager.default
      let documentsDirectory = fileManager.urls(for: .documentDirectory, in: .userDomainMask)[0]
      let destinationURL = documentsDirectory.appendingPathComponent(url.lastPathComponent + "." + fileExtension)
      
      do {
        if fileManager.fileExists(atPath: destinationURL.path) {
          try fileManager.removeItem(at: destinationURL)
        }
        
        try fileManager.moveItem(at: location, to: destinationURL)
        completion(.success(destinationURL))
      } catch let error {
        completion(.failure(error))
      }
    }
    .resume()
  }

  private func saveToPhotoLibrary(
    fileURL: URL,
    format: FileFormat,
    completion: @escaping (Result<Void, Error>) -> ()
  ) {
    PHPhotoLibrary.requestAuthorization { status in
      guard status == .authorized else {
        completion(.failure(NSError(domain: "Failed to require photoLibrary permission", code: -1)))
        return
      }
      
      PHPhotoLibrary.shared().performChanges({
        switch format {
        case .image: PHAssetChangeRequest.creationRequestForAssetFromImage(atFileURL: fileURL)
        case .video: PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: fileURL)
        case .file:
          completion(.failure(NSError(domain: "cannot handle file type assets.", code: -3)))
        }
      }) { success, error in
        if success {
          completion(.success(()))
        } else if let error {
          completion(.failure(error))
        }
      }
    }
  }
}

Additional Requirements

These requirements are already described above. each are marked as #1, #2 and #3.

# 1. allowsInlineMediaPlayback

allowsInlineMediaPlayback is a configuration option for whether HTML5 video plays as inline or as full screen. The default value is false. Therefore, If there is a video in the SDK, It will play as full screen automatically.

To fix this, you should modify the allowsInlineMediaPlayback to true.

# 2. handle target_blank type route

All of the link property of the JavaScript SDK is target="_blank". Thus, It will open with a new tap.
However, WKWebView can't handle target="_blank" automatically, you should add this code example to deal with.

This example is If the link action is from target="_blank", retrieve the link from action and load the URL on the WebView.

# 3. Downloading File, Image or Video

Please be aware that WKWebView does not natively support downloading files such as photos or videos. The above code demonstrates how to intercept URL requests and download files when they are identified as file, images or videos, specifically from Channel Talk.