Develop Reference

how to show only specific part of website in android webview

I wish to show only the login-page element of a URL. My current approach which is not working:
web.setWebViewClient(new WebViewClient() {
#Override
public void onPageFinished(WebView view, String url)
{
view.loadUrl("javascript:document.getElementByClassName('login-page')");
}
});
web.loadUrl("https://www.reddit.com/reddits/login");

For mobile screens you should develop separate screens and embed it.
Another way is if your web page supports p/# tag (i.e) like
https://developer.android.com/guide/components/fundamentals.html#Components
https://www.reddit.com/reddits#login this should navigate the page directly to login form
Anyhow I prefer you should develop the page for mobile screens.

Your approach is close to working, but you should modify the existing page instead of trying to load a subset of the existing page as a new one.
The following hides elements with class SectionToRemove, you could instead hide all and only make visible the area you need:
#Override
public void onPageFinished(final WebView view, String url) {
super.onPageFinished(view, url);
view.loadUrl("javascript:$('.SectionToRemove').hide();");
}
That being said, Reddit has extensive APIs that should be used if possible, this approach may breach Terms of Service.

How to set webviewClient for webView dynamically?

For instance, there is a WebView component in my fragment. I use it to load all webpages by the different urls, sort of stupid but efficient. As you know, we specify our webviewclient (like WvjbWebViewClient or jsBridge) to handle all requests. Now that we want to load third-platform websites with our WebView sometimes, however, we don't want to supply our business function for them, not for anything else, but for our safety of communication.
Our company domain is xxx.com. What I want to do is: when the webview loads those webpages on this domain, use our customer WebViewClient, otherwise use a simple WebViewClient(new a instance). How to resolve it? (Should we consider url redirection?)

WebViewClient allows you to upload any specified URL, selected in the WebView, in WebView itself, and do not run the browser. For this functionality meets shouldOverrideUrlLoading(WebView, String) method. If it returns true - we do not need to launch a third-party browser, and upload their own content here.
Here is an example where we choose if we can open the content in our app, or we need to open browser:
public class MyWebViewClient extends WebViewClient {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if(Uri.parse(url).getHost().endsWith("xxx.com")) {
return false;
}
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
view.getContext().startActivity(intent);
return true;
}
}
This can help if think.

How do I open another app in my WebView app?

I have an Android app with that displays a mobile website (WebView), in the mobile website there are links redirecting to a PDF, Excel and video files.
When try to open it in my regular browser my phone asks to open it with another app or it start a download, so I can open it afterwards.
But in my WebView app it either doesn't work, no response or it displays a "Page unavailable" error.
Is it even possible?

To handle links in WebView, you can use the shouldOverrideUrlLoading method of WebViewClient class. Consider the following example;
WebView webView = (WebView) findViewById(R.id.infoView);
webView.setWebViewClient(new WebViewClient() {
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// Assuming you are giving link to some PDF file.
if (url.contains(".pdf")) {
// Now do what you want to with the url here
}
return true;
}
}
This way, you can intercept any link tapped in WebView and then do whatever you want.

How to handle callbacks in webview

I am working on an android project right now and have a question about how to do callbacks in different webviews. I used JSInterface for my project too. Here I have 2 webviews. One has an index page, anther is a overlay(still a html page though.) What I want to do is if any user clicks on some links on the overlay, it should fire a callback function which is written in the java file where the index page was connected to through JSInterface. It might sound confusing, but I have draw something to help make it clear!
Thanks!

You can use a custom URL scheme like myurl://function for your functionality links. Then write an event handler for the WebView's shouldOverrideUrlLoading event in which you decide how to process the URL: either instruct the webview to load it, or do some custom action.
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
if (url.startsWith("myurl://"))
{
// Parse further to extract function and do custom action
}
else
{
// Load the page via the webview
view.loadUrl(url);
}
return true;
}
I used startsWith to check the URL for this quick and dirty example, but you should consider using android.net.Uri.parse for parsing URLs.
This should allow you to call the Java function foo() without having to go through the first WebView.
If you want to go through the first webview, then you can call a function on the JSInterface like this (where webView1 is the first WebView retrieved through findViewById):
webView1.loadUrl("javascript:myjsinterface.myjsfunc();")

How to display a website and a button in one activity?

I'm making an application that contains button's and those buttons control an embedded browser. My problem is that I want to see the button's and the web page in the same layout, but when i click on a button this will open a web page and don't show the button, can anyone help me?

If I understand correctly your problem is that following a link opens the standard browser not your WebView, right ?
Add this to your WebView to change that behavior
// this is to prevent that when clicking a new URL from the displayed
// page the default web browser launches
webView.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});

You need to use a Layout that supports more than one child. Take a look here