Saving WebView and showing it while offline?

Question

I need to cache a WebView in a way that it would use cache if there is no internet, and when there is internet it will use the online page. Since my class with the WebView does loadUrl() in the onCreateView, it reloads it every time so I need cache for 2 reasons: faster loading, but mainly for offline use of the app.

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.net.ConnectivityManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class CalendarFragment extends Fragment {
    private WebView webView;
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view =  inflater.inflate(R.layout.calendar_layout, container, false);
        webView = (WebView) view.findViewById(R.id.calendarWebView);
        webView.getSettings().setAppCacheEnabled(true);
        webView.getSettings().setDomStorageEnabled(true);
        webView.getSettings().setAllowFileAccess(true);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setAppCachePath(getContext().getCacheDir().getPath());
        webView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
        webView.setWebViewClient(new WebViewClient());
                webView.loadUrl("https://calendar.google.com/calendar/htmlembed?src=wlmacci%40gmail.com&ctz=America%2FToronto");
        //webView.loadUrl("https://sites.google.com/view/wlmac/textfile?");
        //webView.loadUrl("https://google.ca");
        webView.getSettings().setLoadWithOverviewMode(true);
        webView.getSettings().setUseWideViewPort(true);
        return view;
    }
}

I have tried the LOAD_DEFAULT as well as LOAD_CACHE_ELSE_NETWORK and neither seem to work; when I switch away from Calendar fragment and back to it with my WiFi off, I get net::ERR_ADDRESS_UNREACHABLE

Update: Doesn't work with LOAD_CACHE_ONLY either

Update: Added ACCESS_NETWORK_STATE and ACCESS_WIFI_STATE, am now getting net::ERR_INTERNET_DISCONNECTED error

Sources I learned it from: Source 1 Source 2

Possible duplicate of [WebView load website when online, load local file when offline](https://stackoverflow.com/questions/14670638/webview-load-website-when-online-load-local-file-when-offline) — Manoj Perumarath, Mar 09 '19 at 04:07
No I have already incorporated everything and tried all cache modes yet it still does not work — Andrey Starenky, Mar 09 '19 at 04:17
Added JavaScript and other booleans and still doesn't work, check updated code — Andrey Starenky, Mar 09 '19 at 05:00

Manoj Perumarath · Answer 1 · 2019-03-09T05:36:34.047

0

Add these permissions to manifest

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

Try this code,

webView = (WebView) view.findViewById(R.id.calendarWebView);
webView.getSettings().setAppCacheMaxSize( 8 * 1024 * 1024 ); 
webView.getSettings().setAppCachePath( 
getApplicationContext().getCacheDir().getAbsolutePath() );
webView.getSettings().setAllowFileAccess( true );
webView.getSettings().setAppCacheEnabled( true );
webView.getSettings().setJavaScriptEnabled( true );
webView.getSettings().setCacheMode( WebSettings.LOAD_DEFAULT ); 

if ( !isNetworkAvailable() )  //offline
webView.getSettings().setCacheMode( WebSettings.LOAD_CACHE_ONLY );


webView.loadUrl( "https://calendar.google.com/calendar/htmlembed? 
src=wlmacci%40gmail.com&ctz=America%2FToronto" );

Network connectivity checking method

private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService( 
CONNECTIVITY_SERVICE );
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();}

edited Mar 09 '19 at 05:36

answered Mar 09 '19 at 05:16

Manoj Perumarath

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Thank you, but I have tried this. I have the permissions already. getApplicationContext() doesn't work and says "Cannot resolve method getApplicationContext()" and same thing goes for the isNetworkAvailable(), it also can't resolve. – Andrey Starenky Mar 09 '19 at 05:23
you need to add that method in your class, `isNetworkAvailable` – Manoj Perumarath Mar 09 '19 at 05:28
Oh yes my bad. What about the getApplicationContext()? Also shouldn't it not make a difference for checking the network? It is already set to LOAD_CACHE_ELSE_NETWORK so it should still work. Anyways I will add the method, meanwhile what about the getApplicationContext()? – Andrey Starenky Mar 09 '19 at 05:31
Can you please clarify what you mean by that? Also getSystemService() cannot be resolved – Andrey Starenky Mar 09 '19 at 05:35
I did getContext() instead of getApplicationContext() do you think that's fine? – Andrey Starenky Mar 09 '19 at 05:36
What did you change? The edit shows you replaced the same code – Andrey Starenky Mar 09 '19 at 05:39
getApplicationContext() and getSystemService() both remain unresolved – Andrey Starenky Mar 09 '19 at 05:40
Remove which line? I cannot just remove the line, it will not work – Andrey Starenky Mar 09 '19 at 05:42
So I can use getContext() instead of getApplicationContext() correct? – Andrey Starenky Mar 09 '19 at 05:47
context.getSystemService – Manoj Perumarath Mar 09 '19 at 05:50
context. Doesn't work, I did getContext(). It compiles, but when I open with WiFi, switch fragments, turn WiFi off and then go back to it, I get the "net::ERR_CACHE_MISS" error inside the WebView – Andrey Starenky Mar 09 '19 at 05:57

Saving WebView and showing it while offline?

1 Answers1