What is the best method for incorporating a JavaScript redirect into an Android WebView?

Question

What is the best method for incorporating a JavaScript redirect into an Android WebView?

My issue involves loading a page into a webview. Typically, when I use the code

webview.loadUrl(url);

it functions as expected. The url contains a javascript code that redirects the page. Here is the javascript code:

<script type="text/javascript">
        if (!document.cookie || document.cookie.indexOf('AVPDCAP=') == -1)
        { document.write('<scr'+'ipt src="http://some_link_here+Math.floor(89999999*Math.random()+10000000)+'&millis='+new Date().getTime()+'&referrer='+encodeURIComponent(document.location)+'" type="text/javascript"></scr'+'ipt>'); }
</script>

When attempting to load this javascript code into my webview using the following:

String data = javascript_code_above;
topBannerWV.loadDataWithBaseURL("", data, "text/html", "UTF-8", null);

where 'data' represents the javascript code, the page fails to load. I have also tried the following:

topBannerWV.loadDataWithBaseURL("", data, "text/javascript", "UTF-8", null);

however, this only loads the text into the webview. Can someone provide assistance with this matter?

Thank you.

javascript android webview

Answer 1

Answer №1

This is how I have implemented a solution that works flawlessly:

webView.loadUrl("file:///android_asset/html.html");
webView.setWebViewClient(new WebViewClient() {

public void onPageFinished(WebView view, String url) {
    try {           
                webView.loadUrl("javascript:init('" + some parameter + "')");

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
});

The script within the HTML file looks like this:

<script type="text/javascript>
function init(val){
document.getElementById('content').innerHTML=val;
}
window.addEventListener('load',function(){
console.log("Window Loader");
init();
});
</script>

Answer 2

This is how I have implemented a solution that works flawlessly:

webView.loadUrl("file:///android_asset/html.html");
webView.setWebViewClient(new WebViewClient() {

public void onPageFinished(WebView view, String url) {
    try {           
                webView.loadUrl("javascript:init('" + some parameter + "')");

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
});

The script within the HTML file looks like this:

<script type="text/javascript>
function init(val){
document.getElementById('content').innerHTML=val;
}
window.addEventListener('load',function(){
console.log("Window Loader");
init();
});
</script>

Answer 3

Answer №2

The solution has been found.

Instead of directly passing the string to the webview for loading, I took a different approach by first writing it into a file and then loading that file in the webview.

getContext().getApplicationContext().deleteFile("data.html");
Writer output = null;
File dir = getContext().getApplicationContext().getFilesDir();
File file = new File(dir.getAbsolutePath() + File.separator + "data.html");
file.createNewFile();
output = new BufferedWriter(new FileWriter(file));
output.write(WVdata);
output.close();
topBannerWV.loadUrl("file:///" + getContext().getApplicationContext().getFilesDir() + "/data.html");

It's still unclear to me why this solves the issue, as I am not modifying the data string - just storing it in a file instead.

Answer 4

The solution has been found.

Instead of directly passing the string to the webview for loading, I took a different approach by first writing it into a file and then loading that file in the webview.

getContext().getApplicationContext().deleteFile("data.html");
Writer output = null;
File dir = getContext().getApplicationContext().getFilesDir();
File file = new File(dir.getAbsolutePath() + File.separator + "data.html");
file.createNewFile();
output = new BufferedWriter(new FileWriter(file));
output.write(WVdata);
output.close();
topBannerWV.loadUrl("file:///" + getContext().getApplicationContext().getFilesDir() + "/data.html");

It's still unclear to me why this solves the issue, as I am not modifying the data string - just storing it in a file instead.

What is the best method for incorporating a JavaScript redirect into an Android WebView?

Answer №1

Answer №2

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