Develop Reference

Webview shouldOverrideUrlLoading not catching URL requests

I am trying to parse every click event, intercept the http url that attempts to load into the webview, and decide if it should be shown depending on a set of logic as per how the url parses. I have followed the advice on these 3 StackOverflow links:
1) Intercept and override HTTP requests from WebView
2) Android Web-View shouldOverrideUrlLoading() Deprecated.(Alternative)
3) https://stackoverflow.com/a/32711309/2480714
without it fixing my issue. The main issue is that a user clicks on the webview to load a hyperlink and it is seems like the shouldOverrideUrlLoading method is not being called or is not intercepting the url properly every time.
I created my Custom WebViewClient and overrode it first with the intent of stopping all loads without my approval, but I have run into a snag; some urls are loading and bypassing my override methods and some are not. I have no clue why this is happening.
Here is my WebviewClient class:
public class CustomWebViewClient2 extends WebViewClient {
public CustomWebViewClient2(){
}
#Override
public void onPageFinished(WebView view, String url) {
Log.d("log", "(CustomWebViewClient) onPageFinished, URL == " + url);
}
#SuppressLint("NewApi")
#Nullable
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
Log.d("log", "shouldInterceptRequest hit");
return null;
}
#Nullable
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
Log.d("log", "shouldInterceptRequest hit");
return null;
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
Log.d("log", "(CustomWebViewClient) shouldOverrideUrlLoading");
return true;
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
Log.d("log", "(CustomWebViewClient) shouldOverrideUrlLoading");
return true;
}
#Override
public void onLoadResource(WebView view, String url) {
Log.d("log", "intercepting onLoadResource, url == " + url);
}
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
Log.d("log", "onPageStarted url == " + url);
}
}
As you can see, it is overriding the correct methods and should (in theory) never load a URL unless I pass it to the webview to load, but unfortunately some websites are loading, and others are not.
I also tried disabling the cache as per this comment in one of the answers:
"A word of CAUTION! If you intercept an attempt by the browser to
retrieve an image (or probably any resource) and then return null
(meaning let the WebView continue retrieving the image), any future
requests to this resource might just go to the cache and will NOT
trigger shouldInterceptRequest(). If you want to intercept EVERY image
request, you need to disable the cache or (what I did) call
WebView.clearCache(true)"
but to no avail. Why are some URLs loading in and bypassing the override, but others are not?
Update 1: Here is a sample URL https://cookpad.com/us that mirrors the issue I am referring to. It seems to be related to Turbolinks being implemented on the server-side.

android webview custom headers not going out on page resource requests

In my android app I am connecting to a secure site where my login credentials are contained in custom headers. I am able to log in successfully because the custom headers are sent with the new page request.
Based on my custom header information there is specific page functionality which is enabled for my device. The problem is that when I load resources from the home page after login the custom headers that I specify in the webview.LoadUrl(); are not sent. So the end result is that I can log in but do not receive the special functionality that is associated with my device.
I have tried both of these overrides. shouldOverrideUrlLoading seems to work when changing URL's but shouldInterceptRequest does not seem to get called on resource requests? If it is my implementation does not work?
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
request.getRequestHeaders().putAll(getExtraHeaders());
return super.shouldInterceptRequest(view, request);
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url, getExtraHeaders());
return false;
}

See if this works a little better for you:
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.post(new Runnable() {
#Override
public void run() {
view.loadUrl(url, getExtraHeaders());
}
});
// true means: yes, we are overriding the loading of this url
return true;
}
This additional code is just a suggestion/outline and should not be taken as cut/paste ready code
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
String mimetype;
String encoding;
Map<String, String> headers = new HashMap<>();
headers.putAll(request.getRequestHeaders());
headers.putAll(getExtraHeaders());
URL url = request.getUrl().toString();
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
for (String key : headers.keySet()) {
conn.setRequestProperty(k, headers.get(k));
// TODO look for the mimetype and encoding header information and set mimetype and encoding
}
return new WebResourceResponse(mimetype, encoding, conn.getInputStream());
// return null here if you decide to let the webview load the resource
}

Maybe try a different approach, store whatever your need in a cookie for your host using WebKit's CookieManager and use the request's cookie header instead of your custom headers

android webview measure times of all resources

It is possible to measure the load time of all the resources of a webview?
For example for loading the complete web, I use:
public void onPageStarted(WebView view, String url, Bitmap favicon) {
startingTime = System.currentTimeMillis();
super.onPageStarted(view, url, favicon);
}
public void onPageFinished(WebView view, String url) {
timeElapsed = System.currentTimeMillis() - startingTime;
super.onPageFinished(view, url);
}
but to measure the load of CSS, images, etc. I use
public HashMap<String, Long> resources = new HashMap<String, Long>();
public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request){
resources.put(request.getUrl().toString(), System.currentTimeMillis());
WebResourceResponse response = super.shouldInterceptRequest(view, request);
return response;
}
public void onLoadResource(WebView view, String url) {
if(resources.containsKey(url)){
Long timeStartResource = resources.get(url);
Long timeElapseResource = System.currentTimeMillis() - timeStartResource;
}
super.onLoadResource(view, url);
}
I thought the onLoadResource method is executed when the resource was loaded but according to documentation
public void onLoadResource (WebView view, String url).
Notify the host application that the WebView will load the resource specified by the given url.
And
public WebResourceResponse shouldInterceptRequest (WebView view, WebResourceRequest request)
Notify the host application of a resource request and allow the application to return the data. If the return value is null, the WebView will continue to load the resource as usual. Otherwise, the return response and data will be used.
Both they run before loading the resource. Is there any way to measure these times?

There is a great HTML5 API for that accessible to your page. See http://www.sitepoint.com/introduction-resource-timing-api/
Starting from KitKat, WebView is based on Chromium, which supports this API. To check that, open remote web debugging for your app (assuming that you have enabled JavaScript for your WebView), and try evaluating in console:
window.performance.getEntriesByType('resource')
You will get an array of PerformanceResourceTiming objects for each resource your page has loaded.
In order to transport your information to Java side, you can use an injected Java object.

That you can done using onPageFinished() and answer of this question is already given description here.

WebView loads url more than a time in android

webview in android loads more than once while loading the url.
Below is the code.
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
if (url.contains(".pdf")) {
String[] spliturl = url.split("http://someurl/");
String googleurl = "http://docs.google.com/viewer?embedded=true&url=";
System.out.println("Google Url"+googleurl);
System.out.println("spliturl"+spliturl[1]);
view.loadUrl(googleurl+spliturl[1]);
}
else
view.loadUrl(url);
return true;
}
});
I am splitting the url as it contains more than one url to be passed on google document viewer for rendering the pdf document.
First time the url is correctly split and the url is concatenated to open in google docs but the webview executes again there by giving an ArrayIndexOutOfBoundsException at spliturl[1].
Could anybody let me know why is this executing again.
thanks.

I don't know why it gets called multiple times, but the solution is to handle it in onPageStarted rather than in shouldOverrideUrlLoading
boolean calledOnce=false;
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
public void onPageStarted(WebView view, String url, Bitmap favicon) {
if (url.contains(".pdf") && !calledOnce) {
String[] spliturl = url.split("http://someurl/");
String googleurl = "http://docs.google.com/viewer?embedded=true&url=";
System.out.println("Google Url"+googleurl);
System.out.println("spliturl"+spliturl[1]);
url = googleurl+spliturl[1];
calledOnce = true;
}
super.onPageStarted(view, url, favicon);
}

You should always check if an array has a size more than the index requested:
if (url.contains(".pdf") && url.split("http://someurl/").size()>2){
// your code
}
Don't know why it gets called though - probably multiple redirections.

Android detect webview URL change

I have a webview in my android app and would like to detect when the url changes.
I want to use this to hide the info button in the top bar when the user is on the info.php page and show it again when he is not on the info.php page.
I googled but can't find any working code, can anybody help me?

I know I'm late to the game but I ran into this issue over and over ... I finally found a sloution which is pretty straight forward. Just override WebViewClient.doUpdateVisitedHistory
override fun doUpdateVisitedHistory(view: WebView?, url: String?, isReload: Boolean) {
// your code here
super.doUpdateVisitedHistory(view, url, isReload)
}
It works with all url changes even the javascript ones!
If this does not make you happy then I don't know what will :)

You can use WebViewClient.shouldOverrideUrlLoading to detect every URL changes on your WebViewClient

For those load url by javascript. There is a way to detect the url change by JavascriptInterface. Here I use youtube for example. Use JavaScriptInteface has async issue, luckily its just a callback here so that would be less issue. Notice that #javascriptinterface annotation must be existed.
{
youtubeView.getSettings().setJavaScriptEnabled(true);
youtubeView.setWebViewClient(mWebViewClient);
youtubeView.addJavascriptInterface(new MyJavaScriptInterface(),
"android");
youtubeView.loadUrl("http://www.youtube.com");
}
WebViewClient mWebViewClient = new WebViewClient() {
#Override
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:window.android.onUrlChange(window.location.href);");
};
};
class MyJavaScriptInterface {
#JavascriptInterface
public void onUrlChange(String url) {
Log.d("hydrated", "onUrlChange" + url);
}
}

if you override this method of WebViewClient you will be able to handle url changes, and javascript url changes:
public class YXWebViewClient extends WebViewClient {
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
Log.i("Listener", "Start");
}
#Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
Log.i("Listener", "Finish");
}
}
and then in your WebView set the WebViewClient
yxWebViewClient = new YXWebViewClient();
webview.setWebViewClient(yxWebViewClient);

I used this method:
webView.setWebChromeClient(new WebChromeClient()
{
#Override public void onProgressChanged(WebView view, int newProgress) {
if (view.getUrl().equals(mUrl))
{
}
else
{
mUrl = view.getUrl();
// onUrlChanged(mUrl) // url changed
}
super.onProgressChanged(view, newProgress);
}
};
);
mUrl is a fields as String...

Try to use onLoadResource. It will be called at least 1 time even if you are using
JS to change your url. But it may be called more than one time, so be careful.

Method onPageFinished seems to work at least in modern WebViews.

An implementation of rinkal-bhanderi's answer would look like this:
class MyWebClient(
private val myCustomMethod: () -> Unit) : WebViewClient() {
override fun shouldOverrideUrlLoading(view: WebView?,
url: String?): Boolean {
myCustomMethod()
return true
}
}
}
And you would use it like:
webview.webViewClient = MyWebClient(::hideButton)
Where webview is the actual webview you get from calling FindViewById or the object reference you get from binding. And hideButton is a method accessible in the same scope last expression is evaluated.

I had an interesting problem that brought me to this question and happy to provide a solution that may help someone else if they come this way due to a googlebingyahoo search.
mwebVew.reload() would not pick up the new URL I wanted to load once I returned from a preference screen where I either logged on the user or logged off the user. It would update the shared preferences well enough but not update and replace the url web page. So after a few hours of not seeing an answer I tried the following and it worked a real treat.
mWebView.resumeTimers();
Here is the link to the doco if you want more info.
Hope it saves someone else the pain I went through, and happy to have someone tell me I should of implemented it another way.

I had the same problem. So i've solved this problem by overriding public void onPageStarted(WebView view, String url, Bitmap favicon) method as follows:
webView.setWebViewClient(new WebViewClient(){
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon)
{
// Here you can check your new URL.
Log.e("URL", url);
super.onPageStarted(view, url, favicon);
}
});
Also you can overridepublic void onPageFinished(WebView view, String url) method to get a new URL at the end of page load process.

My requirement was to handle the visibility of a floating button in my page based on the url change.
if url is changing from https/ooooo//login to https/ooooo//homepage
it may not be registered in onPageFinished or shouldOverrideUrlLoading.
This was the issue I was facing.
I fixed that issue by following method:
#Override
public void doUpdateVisitedHistory(WebView view, String url, boolean isReload) {
super.doUpdateVisitedHistory(view, url, isReload);
String currentUrl = view.getUrl();
}
*please don't use url which we are getting with doUpdateVisitedHistory method.That will be the basic url.so go with view.getUrl().
:)

Use WebViewClient.shouldOverrideUrlLoading() when the base/host url changes. Use Use WebViewClient.doUpdateVisitedHistory() method of webview if the base url doesnt change like it happens in single page applications and it detects URL change by javascript which does not lead to a web page reload. #Helin Wang

This will help to detect redirect caused by javascript.
WebViewClient mWebViewClient = new WebViewClient() {
#Override
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:window.android.onUrlChange(window.location.href);"); }
};
myWebView.setWebViewClient(mWebViewClient);
}
#JavascriptInterface
public void onUrlChange(String url) {
Toast.makeText(mContext, "Url redirected",Toast.LENGTH_SHORT).show();
}