Kotlin Android WebView

Android WebView is a view component which displays the web pages in the application. It uses a WebKit engine to show the web pages. The android.webkit.WebView class is the subclass of AbsoluteLayout class.

The loadUrl() and loadData() methods of WebView are used to load and display the web pages. To learn more about Android WebView go to https://www.javatpoint.com/android-webview-example

There are different ways to load the web page in WebView such as:

Load the HTML content as a string in the class:

val wedData: String =  "<html><body><h1>Hello, Javatpoint!</h1></body></html>"
val mimeType: String = "text/html"
val utfType: String = "UTF-8"
webView.loadData(wedData,mimeType,utfType)

Load the web page (.html, .jsp, etc.) from within the application. In such case, web pages are placed in assets directory.

Load the web URL inside WebView as:

Kotlin Android WebView Example

In this example, we will load the web URL in the WebView component and override the URL.

Directory structure

activity_main.xml

Add the WebView component in the activity_main.xml file.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="example.javatpoint.com.kotlinwebview.MainActivity">


    <WebView
        android:id="@+id/webView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>
</LinearLayout>

AndroidMenifest.xml

In the AndroidMenifest.xml file, add the Internet permission to connect the network connection.

<uses-permission android:name="android.permission.INTERNET"/>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="example.javatpoint.com.kotlinwebview">
    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MainActivity.kt

Add the following code in the MainActivity.kt class. In this class, we are using the loadUrl() method of WebView to load web URL.

Create a MyWebViewClient class that extends the WebViewClient that override the shouldOverrideUrlLoading() method.

package example.javatpoint.com.kotlinwebview

import android.app.Activity
import android.os.Build
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.annotation.RequiresApi
import android.webkit.WebResourceError
import android.webkit.WebResourceRequest
import android.webkit.WebView
import android.webkit.WebViewClient
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

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

      /*  val wedData: String =  "<html><body><h1>Hello, Javatpoint!</h1></body></html>"
        val mimeType: String = "text/html"
        val utfType: String = "UTF-8"
        webView.loadData(wedData,mimeType,utfType)*/

        /* val myWebUrl: String = "file:///android_asset/index.html"
         webView.loadUrl(myWebUrl)*/

        webView.webViewClient = MyWebViewClient(this)
        webView.loadUrl("https://www.javatpoint.com/")
    }
    class MyWebViewClient internal constructor(private val activity: Activity) : WebViewClient() {

        @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
        override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean {
            val url: String = request?.url.toString();
            view?.loadUrl(url)
            return true
        }

        override fun shouldOverrideUrlLoading(webView: WebView, url: String): Boolean {
            webView.loadUrl(url)
            return true
        }

        override fun onReceivedError(view: WebView, request: WebResourceRequest, error: WebResourceError) {
            Toast.makeText(activity, "Got Error! $error", Toast.LENGTH_SHORT).show()
        }
    }
}

Output: