CODEWITHSUNDEEP
androidandroid-webview
FunctionallyReactive
FunctionallyReactive

Reputation: 579

Complete AdBlock inside WebView

I am about to roll out WebView AdBlocking in my android app. I want to know if this will effectively block ads or if there is more to be done say within the Webview itself which I have not modified. Basically I have a host file of stored in Android assets which lists hundred of ad server sites. I read this file in to my AdBlocker and then apply it inside the WebViewClient as follows:

// AdBlocker.isAdURL(String url)

 public Boolean isAdURL(String url){
      Boolean retValue = false;
      if ((url == null) || (url.isEmpty()))
        return false;
      if ((adServers == null)|| (adServers.size() <1))
        return false;
      try{
        String domainName = getUrlsDomain(url);
        if (adServers.contains(domainName)) {
            retValue = true;
        }
    } catch(URISyntaxException e){

    }

    return retValue;
}

And I only use this in WebViewClient as follows:

@Deprecated
@Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {

      if (adBlocker.isAdURL(url)) {
         ByteArrayInputStream nada = new ByteArrayInputStream("".getBytes());
        return new WebResourceResponse("text/plain", "utf-8", nada);
     }
    return super.shouldInterceptRequest(view, url);
}

And similarly:

 @Override
 public WebResourceResponse shouldInterceptRequest(WebView view,  WebResourceRequest request) {
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        if (adBlocker.isAdURL(request.getUrl().toString())) {
            ByteArrayInputStream nada = new    ByteArrayInputStream("".getBytes());
            return new WebResourceResponse("text/plain", "utf-8", nada);
        }

    }

    return super.shouldInterceptRequest(view, request);
}

Anything more need to be done? Or is that it? Any need to keep a whitelist or will this generally work assuming my list of adservers is current?

Upvotes: 5

Views: 13931

Answers (2)

Code on the Rocks
Code on the Rocks

Reputation: 17824

If anyone is looking for a simpler way to do this, the AdBlock plus Github page offers an AdblockWebView. To use it, you add this line to your Gradle file:

implementation 'org.adblockplus:adblock-android-webview:3.0'

And then add this to your layout's XML file:

<org.adblockplus.libadblockplus.android.webview.AdblockWebView
    android:id="@+id/main_webview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

Upvotes: 3

Mikhail Naganov
Mikhail Naganov

Reputation: 6871

This implementation is basically the same as the "whitelist" feature in Cordova. They also use shouldInterceptRequest for blocking requests to non-whitelisted sites. There known shorthands of this approach, e.g. it doesn't catch requests done via WebSockets protocol (see this book excerpt), but in general it's a recommended approach (look for shouldInterceptRequest in that document).

In order to do better, you will need to do all the content loading yourself (using some HTTP client), filter out and sanitize the content, and then pass the results to WebView in order to render. This is how GMail Android app works for example (they do actual sanitization on the server, but it's also possible to do it on the device).

Upvotes: 3

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