I have a div called downloadapp that I'd like to display to users who visit my mobile website instead of using my Android app. So I need to hide that div for users who already use my app.
My code:
private void startWebView(String url) {
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient() {
//On error, open local file
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
webView.loadUrl("file:///android_asset/www/myerrorpage.html");
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
#Override
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:document.getElementById('downloadapp').style.display = 'none';");
}
});
webView.loadUrl(url);
}
Problem:
My app loads the div first and its actually being displayed for a couple of seconds. Then suddenly, the whole webpage loaded in the app disappears and a blank page with the word "none" is the only thing that is left on the screen.
Is there something wrong with the way I try to hide the div "downloadapp" or what am I missing here?
What I want it to do is immediately hide the div before the webpage is being displayed.
This is happening on newer versions of WebView -- if your app is targeting API level 19 or above (KitKat), then if a javascript: URL returns a value, this value is interpreted as content for a new web page to open. In your case, as 'none' is the return value of the assignment, it is used as the content for a new page.
Just put void(0); at the end of your code in javascript: to prevent it from returning a value.
Related
I realized an Android program that loads a HTML file into a WebView, the HTML file loads Leaflet.js that shows different styles of maps based on the provider you gave it.
I load the page in the OnCreate() method with this instruction:
myWebView.loadUrl("file:///android_asset/test.html");
After that, I need to take the list of different maps from a Handler (with class name JavascriptInterface.java) that I added to the WebView like this:
myWebView.addJavascriptInterface(new JavaScriptInterface(this, myWebView), "MyHandler");
The final code needs to look like this:
myWebView.loadUrl("file:///android_asset/test.html");
myWebView.loadUrl("javascript:window.MyHandler.getMaps()");
The problem is that the first loadUrl() isn't fast enough, so the second loadUrl goes before the map is initialized, causing a lot of problems.
The temporary, and also horrible, solution that I found is to hold the second loadUrl for 1 second before executing it, like this:
myWebView.loadUrl("file:///android_asset/test.html");
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
// Actions to do after 1 second
myWebView.loadUrl("javascript:window.MyHandler.getMaps()");
}
}, 1000);
There is a better way of executing an instruction after another one? I already tried using an ASyncTask, but there is the possibility that I didn't implemented it well.
Please call myWebView.loadUrl("javascript:window.MyHandler.getMaps()"); inside Webview onPageFinished event.
myWebView.setWebViewClient(new WebViewClient() {
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
Log.d("WebView", "onPageStarted " + url);
}
#Override
public void onPageFinished(WebView view, String url) {
myWebView.loadUrl("javascript:window.MyHandler.getMaps()");
}
});
myWebView.loadUrl("file:///android_asset/test.html");
I have a WebView in Android. I load page in webview from url and i want to hide some elements that the webpage actually has. I did it after page has loaded. And it give me only 'none' text in the webview nothing more. I tried as follows
#Override
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:window.document.getElementsByClassName('cdo-search')[0].style.display='none';");
if (pd.isShowing()) {
pd.dismiss();
}
}
How can we hide element that webpage actually has?
My previous answer was not it. after testing I found out that this solved the problem. The issue is not with android or webview. it's the way url based javascript execution works.
#Override
public void onPageFinished(WebView view, String url) {
view.loadUrl("javascript:function a(){window.document.getElementsByClassName('cdo-search')[0].style.display='none';}; a()");
if (pd.isShowing()) {
pd.dismiss();
}
}
I'm not entirely sure what's the reason but if i had to guess, what ever is returned by the statement you write in this format other than undefined, will be set as the document's html.
in other words, you cannot do any kind of assignment operation in outer scope, while executing JS in this format.
my testing method:
i put these two in the address-bar of this particular Stack overflow page.
javascript:function a(){window.document.getElementsByClassName('question-hyperlink')[0].style.display='none';}; a()
javascript:window.document.getElementsByClassName('question-hyperlink')[0].style.display='none';
in the first attempt the qustion disappeared as expected but in second one, the page turned into "none".
Background
This may seem to be a duplicate to many other questions. Trust me that it isn't.
I'm trying to load html data into a WebView, being able to capture user hyperlink requests. In the process I've found this answer which does exactly what I want to do, except it captures other requests to things like CSS files and images:
// you tell the webclient you want to catch when a url is about to load
#Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request){
return true;
}
// here you execute an action when the URL you want is about to load
#Override
public void onLoadResource(WebView view, String url){
if( url.equals("http://cnn.com") ){
// do whatever you want
}
}
I've shut off automatic image loading, network loads, and Javascript execution:
settings.setBlockNetworkLoads(true);
settings.setBlockNetworkImage(true);
settings.setJavaScriptEnabled(false);
But these do nothing as to preventing the capture of these requests.
Maybe there's a different procedure to capturing the link click, but it was either this or to stop the loading of external resources.
Question
How do I prevent WebView from capturing (or attempting to load) resource requests like CSS, JS, or images?
Otherwise if I can't prevent capturing or attempting to load, how can I differentiate between links clicked and web resources?
Thanks ahead!
You could override WebViewClient's shouldInterceptRequest and return some non-null response instead of the CSS, JS, images, etc. being fetched.
Example:
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
Log.d(TAG, "shouldInterceptRequest: " + url);
if (url.contains(".css")
|| url.contains(".js")
|| url.contains(".ico")) { // add other specific resources..
return new WebResourceResponse(
"text/css",
"UTF-8",
getActivity().getResources().openRawResource(R.raw.some_css));
} else {
return super.shouldInterceptRequest(view, url);
}
}
where R.raw.some_css is:
body {
font-family: sans-serif;
}
Note:
I'm not sure what pages you're loading, but this approach may ruin the look of the page.
I've found a way to ignore automated WebView resource requests.
By ignoring requests in the first second of WebView initialization, I am able to isolate user based clicks from the rest:
final Long time = System.currentTimeMillis()/1000;
//load up a WebView, define a WebViewClient for capturing link clicking
WebView webview = new WebView(this);
WebViewClient webviewClient = new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request){
return true;
}
#Override
public void onLoadResource(WebView view, String url){
Long currentTime = System.currentTimeMillis()/1000;
if (currentTime - time > 1) {
//do stuff here
}
}
};
I have not tested this solution without blocking JavaScript execution and automatic image loading, but it should work regardless:
WebSettings settings = webview.getSettings();
settings.setBlockNetworkLoads(true);
settings.setBlockNetworkImage(true);
settings.setJavaScriptEnabled(false);
Short answer is, you can't.
A longer answer could be like this: you won't be able to do that because it is designed to be "capture all or capture nothing". Web requests are a general concept, not tied to a particular resource like images or css - in fact, it does not have any clue of what does are. That's why you won't find anything.
Do like this: in shouldOverrideUrlLoading, instead of returning true all the time, you only return true for the urls you want to handle yourself. For all other cases, like css and so forth, you return false, so the webview will take care of that for you.
For example:
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// Ignore css and js
if (url.endsWith(".css") || url.endsWith(".js")) {
return false;
}
return true;
}
Good Day,
I have a webview in Android app which loads a resource that uses html and javascript:
WebView.getSettings().setJavaScriptEnabled(true);
//webView.getSettings().setDomStorageEnabled(true);
//webView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
//webView.getSettings().setLoadWithOverviewMode(true);
//webView.getSettings().setUseWideViewPort(true);
//webView.getSettings().setBuiltInZoomControls(true);
webView.setWebViewClient(new WebViewClient() {
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
//webView.loadUrl("file:///android_asset/Index.html");
webView.loadUrl("http://foo.com/newbilltemplate/");
The comments show you what I've tried so far. Also I tried local and online resource and the problem still exist.
The index.html page doesn't use Javascript but when a button is clicked it uses some Javascript calculations to display in the next page.
Thanks,
I am new to android. We have a web application where on menu click we are hiding some div and showing other. Now I have to load the page in web view which I have done well with URL. But there is a condition with a java script function based on which I should load page. And it is the problem. The function is as follows ::
<a href="javascript:void(0)" onclick="getmenudata('Home')">
or
<a href="javascript:void(0)" onclick="getmenudata('About')">
Now my question is, is it possible to call such type of java script function from android ?!! If possible please can some body help me to how to write my URL using this type of function ?
I solve it.
just add this line onPageFinish() >>>
#Override
public void onPageFinished(WebView view, String url) {
webview.loadUrl("javascript:getmenudata('Home')");
}
// here getmenudata is my java script function and Home is my param value.
And override this method as follows >>>
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url){
view.loadUrl(url);
return true;
}