Is it possible to prevent a WebView from caching data in /data/data/???/cache/webViewCache? I've set the following on the WebSettings but the cache folder is still used:
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
I've noticed that the cache files are deleted on application exit or when the application goes into the background but I'd prefer for them not to be created at all. Furthermore I'd like to prevent the use of the webview.db & webviewCache.db found in /data/data/???/database. I currently delete the databases like so:
context.deleteDatabase("webview.db");
context.deleteDatabase("webviewCache.db");
This appears to have the desired effect and the files don't appear to be recreated again for use. Is it safe to assume this is the case?
The notes on this page lead me to believe they don't want you to have fine access to the cache:
http://developer.android.com/reference/android/webkit/CacheManager.html
As far as I can tell, there are (at least) two ways around keeping cache. I haven't written any of this in an app, so no guarantees:
(1) Every time your WebView finishes a page, clear the cache. Something like this in your WebViewClient:
#Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
view.clearCache(true);
}
(2) If you don't care too much what is stored, but just want the latest content, you might be able to achieve this by setting the right http headers on loadUrl (obviously you'd want to test this against your server). Also, this is only available for Android API 8+
Map<String, String> noCacheHeaders = new HashMap<String, String>(2);
noCacheHeaders.put("Pragma", "no-cache");
noCacheHeaders.put("Cache-Control", "no-cache");
view.loadUrl(url, noCacheHeaders);
Maybe you tried this, but maybe also set the WebView Cache size to something small. I'm not sure if 0 will work, so maybe 1:
wv.getSettings().setAppCacheMaxSize(1);
Good Luck!
In my application (on Android 4.2.2) I load on a webview a web page with images that I can change at runtime (I replace the images while keeping the path). The Matt's solution (1)
#Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
view.clearCache(true);
}
works for me, the solution (2) no!
Cheers
Related
I have a hybrid application where I have a WebView which is implementing the shouldOverrideUrlLoading method (both the deprecated and the newest version). This should take over control before loading any external links or certain links within my domain. Without going into specifics, the code looks roughtly like this:
private WebView mWebView;
mWebView.setWebViewClient(new myWebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if(url.isExternal() || url.contains("#specialCase")) {
// Do actions
return true;
}
return super.shouldOverrideUrlLoading(view, url);
}
});
I have noticed that all external links work properly, however shouldOverrideUrlLoading is not being called at all when the link is within my domain, so there is no way for me to detect those cases where I want to take over control.
The android documentation states
Give the host application a chance to take over the control when a new
url is about to be loaded in the current WebView.
Does that new mean different domain? Is there anything I am missing or doing wrong? Any ideas on how to detect the user has clicked a link pointing to the same domain?
Thank you in advance.
Finally found the reason why shouldOverrideUrlLoading was never been called.
Apparently the method is only called when the actual loading is about to start. Our web application is a single-page application, hence even though the URL changes, no new page is loaded and shouldOverrideUrlLoading is not called.
I am using WebView to render local HTML pages loaded from a string, and for security reasons need to block loading any external resources, but need to notify the user if anything was actually blocked and give the user an option to fully load the page with remote images/scripts.
I'm initially blocking network resources with webView.getSettings().setBlockNetworkLoads(true). This works well. Next I need to determine if the loaded HTML content actually contained any references to external networked resources that were blocked. Can anyone please tell me how to do that?
I would like this to work with API 8
You need to do the following:
class MyWebViewClient extends WebViewClient {
#Override
public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
// This method will get called when resources are to be loaded
return new WebResourceResponse(null, null, new ByteArrayInputStream(new byte[0]));
}
}
Then assign this client to your webview and handle resource loading in the above method.
This way you should be able to disable loading external resources without using the setBlockNetworkLoads(true) method and get the callback at the same time.
I have an app with a previously-existing, web-based registration process that I am trying to use inside a WebView. I need to add some style tags to the html in order to hide some elements for better displaying the content inside my app. I can get it to work on initial load, but I cannot figure out how to do it from one page to the next inside the WebView. Here is what I have working:
On initial load of the site, I am getting the raw html and appending "<style>MY STYLES HERE</style>" to the string before calling
wv.loadDataWithBaseURL(url, rawHtml, null, "UTF-8", url);
This works perfectly, but if a user clicks a link on the page and it loads another page into the WebView, then this code does not get called and the style tag is lost.
I assume I need to override "shouldOverrideUrlLoading" in the WebViewClient, but I don't know how to intercept the html from here. I thought I would try something like:
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
String rawHtml = getRawHtml(url) + "<style>...</style>";
wv.loadDataWithBaseURL(url, rawHtml, null, "UTF-8", url);
}
But this obviously sends it into an endless loop of intercepting the load to start a new load.
I have also tried overriding onPageFinished and doing:
wv.loadUrl("javascript:(function() { ... })()");
which works, except that it waits until the entire page is loaded before executing. This causes the page to appear loaded with all of the UI elements in tact, and then all of the ones I am trying to hide suddenly disappear. My ultimate goal is to enhance the look and feel of the site on a mobile device, so this is not an option.
Is there something else I can do in "shouldOverrideUrlLoading" to inject style tags? Or if not, what else can I try?
I've run into this problem, and depending on the number of redirects, etc, we have not been able to make the injected JavaScript available all the time.
At minimum, you should use the wv.loadUrl("javascript:(function() { ... })()"); approach, but call it in both onPageStarted() and onPageFinished().
Depending on the complexity of your pages, you might need to inject the JavaScript in onLoadResource() as well.
Does anyone knows an alternative to Android's webview component ? For some reasons, it's functionality's are insufficient for me : I need to be able to catch every single request to some url, when i'm browsing a wml page (wap). Anyway, I need to be able to do stuff that Android's webview is not made for.
I thought "hey, let's play with the source code, I'm pretty sure that webviews are using apache.org librairies to access internet".
Oh boy was I mistaken. Webviews use native code, and that's where I'm stuck.
So I was wondering if anyone knew of another web browser view, in pure java, that would be open source and nice. It's not a problem if it's slow, i'm displaying some basic wap pages...
Thanks in advance.
You can extend WebView's functionality by using setWebViewClient & setWebChromeClient.
WebView.setWebViewClient(new MyWebViewClient());
WebView.setWebChromeClient(new WebChromeClient() {..}
You can handle each and every request sent/received from the WebView by overriding the below methods:
public boolean shouldOverrideUrlLoading(WebView view, String url) {..}
public void onPageStarted(WebView view, String url, Bitmap favicon) {..}
public void onPageFinished(WebView view, String url) {..}
The crosswalk project: https://crosswalk-project.org/ might be what you need. But beware, there are places where it differs from the stock webview. In some ways better, in some ways worse. For example, it supports WebGL (good), but currently the background cannot be transparent (bad). The really good news, it seems to be very actively supported, running it's own Jira to track and fix and Intel seems to be very involved.
Try to see how was Opera Mini programmed.
But I think you must program it if you want another one . But i would be surprised if it has a nice performance.
Try this:
goButton4.setOnClickListener(new OnClickListener() {
public void onClick(View view) {
Uri uri = Uri.parse("http://tory.com/");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
});
hey, an android noob needs help here.
i'm trying to get my webview browser to delete the browser history after the homepage has been loaded (so the next user that comes around this public app doesn't see the previous session)
i've made a webview client and put a
public void onPageFinished(WebView webView, String Url ) {
Browser.clearHistory();
but don't know how to change the String Url to the url of the apps homepage.
I also tried adding a second function to my homebutton onclicklistener, but no luck as well, if someone wants to help i can paste that bit of code as well.
thanks
Here how I did;
#Override
public void onPageFinished(WebView view, String url) {
junc.pg.setVisibility(View.INVISIBLE);
if(url.indexOf("a_string_unique_to_your_homepage")!=-1) {
view.clearHistory();
}
}
Here, you can define a unique string for your url. For example if your homepage url is
www.example.com
you can call it with
www.example.com?12345abc
and search for this unique number 12345abc.
It works, I have tested several times.
Sorry Matt you can´t delete your Browser history programatically in Android.
you will achieve that manually
Browser ..> Settings > Clear History > OK
What about?
Browser.clearHistory(getContentResolver());
Browser.clearSearches(getContentResolver());