Webview in Android

In Android WebView is used to display HTML page in app. We can use android WebView to load HTML page into android app.

Android WebView component is a full-fledged browser implemented as a View subclass to embed it into our android application.

Importance Of Android WebView

For HTML code that is limited in terms of scope, we can implement the static method fromHtml() that belongs to the HTML Utility class for parsing HTML-formatted string and displaying it in a TextView.  TextView can render simple formatting like styles (bold, italic, etc.), font faces (serif, sans serif, etc.), colors, links, and so forth. However, when it comes to complex formatting and larger scope in terms of HTML, then TextView fails to handle it well. For example browsing Facebook won’t be possible through a TextView. In such cases, WebView will be the more appropriate widget, as it can handle a much wider range of HTML tags. WebView can also handle CSS and JavaScript, which Html.fromHtml() would simply ignore. WebView can also assist with common browsing metaphors, such as history list of visited URLs to support backwards and forwards navigation. Still WebView comes with its own set of cons such as it’s a much more expensive widget to use, in terms of memory consumption than a TextView. The reason for this increased memory is because WebView is powered by WebKit/Blink that are open source Web rendering engine to power content in browsers like Chrome.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <WebView
        android:id="@+id/webView1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>
</LinearLayout>

Android WebView loadUrl

Once we’ve obtained a reference to the WebView we can configure it and load URLs via HTTP. WebView loadUrl() method is used to load the URL into the WebView as shown below

Before we start trying around with the url there are two critical aspects we should take a look at:

1. Supporting JavaScript: JavaScript is by default turned off in WebView widgets. Hence web pages containing javascript references won’t work properly. To enable java script the following snippet needs to be called on the webview instance:
2. Adding Permissions: To fetch and load the urls in the WebView we need to add permissions to access the internet from within the app else it won’t be able to load the webpages. The following line of code needs to be added in the AndroidManifest.xml file above the application tag as shown below:

MainActivity.java

package com.androidian.webview;

import androidx.appcompat.app.AppCompatActivity;

import android.app.ProgressDialog;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends AppCompatActivity {

    private WebView webView;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //Get webview
        webView = (WebView) findViewById(R.id.webView1);
        startWebView("https://androindian.com/");
    }

    private void startWebView(String url) {
        //Create new webview Client to show progress dialog
        //When opening a url or click on link
        webView.setWebViewClient(new WebViewClient() {
            ProgressDialog progressDialog;

            //If you will not use this method url links are opeen in new brower not in webview
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return true;
            }

            //Show loader on url load
            public void onLoadResource(WebView view, String url) {
                if (progressDialog == null) {
                    // in standard case YourActivity.this
                    progressDialog = new ProgressDialog(MainActivity.this);
                    progressDialog.setMessage("Loading...");
                    progressDialog.show();
                }
            }

            public void onPageFinished(WebView view, String url) {
                try {
                    if (progressDialog.isShowing()) {
                        progressDialog.dismiss();
                        progressDialog = null;
                    }
                } catch (Exception exception) {
                    exception.printStackTrace();
                }
            }
        });
    }
}

Androidmanifest.xml

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