Programming Desire: 12/15/18

If you are having an app on Google Play Store and you want that whenever you update the app on playstore and when the user opens the older version of app he/she will get a dialog that there is an Update available .
Each time the user will open the app he/she will get the same dialog until he/she updates the app.

Advantages:

This will inform the user as a notice that there is an update.

Users will have the latest version of app.
Automatically checks for update in the background.
There is also an option for mannual check and automatic check.

How to use:

Step-I
I have already create a class(AppUpdateChecker.java) to achieve this feature that will handle it automatically.

AppUpdateChecker.java

 package com.programmingdesire;  
 import android.app.Activity;  
 import android.app.ProgressDialog;  
 import android.content.DialogInterface;  
 import android.content.Intent;  
 import android.content.pm.PackageInfo;  
 import android.content.pm.PackageManager;  
 import android.net.Uri;  
 import android.os.AsyncTask;  
 import android.support.v7.app.AlertDialog;  
 import android.widget.Toast;  
 import org.jsoup.Jsoup;  
 public class AppUpdateChecker {  
   private Activity activity;  
   public AppUpdateChecker(Activity activity) {  
     this.activity = activity;  
   }  
   //current version of app installed in the device  
   private String getCurrentVersion(){  
     PackageManager pm = activity.getPackageManager();  
     PackageInfo pInfo = null;  
     try {  
       pInfo = pm.getPackageInfo(activity.getPackageName(),0);  
     } catch (PackageManager.NameNotFoundException e1) {  
       e1.printStackTrace();  
     }  
     return pInfo.versionName;  
   }  
   private class GetLatestVersion extends AsyncTask<String, String, String> {  
     private String latestVersion;  
     private ProgressDialog progressDialog;  
     private boolean manualCheck;  
     GetLatestVersion(boolean manualCheck) {  
       this.manualCheck = manualCheck;  
     }  
     @Override  
     protected void onPostExecute(String s) {  
       super.onPostExecute(s);  
       if (manualCheck)  
       {  
         if (progressDialog!=null)  
         {  
           if (progressDialog.isShowing())  
           {  
             progressDialog.dismiss();  
           }  
         }  
       }  
       String currentVersion = getCurrentVersion();  
       //If the versions are not the same  
       if(!currentVersion.equals(latestVersion)&&latestVersion!=null){  
         final AlertDialog.Builder builder = new AlertDialog.Builder(activity);  
         builder.setTitle("An Update is Available");  
         builder.setMessage("Its better to update now");  
         builder.setPositiveButton("Update", new DialogInterface.OnClickListener() {  
           @Override  
           public void onClick(DialogInterface dialog, int which) {  
             //Click button action  
             activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id="+activity.getPackageName())));  
             dialog.dismiss();  
           }  
         });  
         builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {  
           @Override  
           public void onClick(DialogInterface dialog, int which) {  
             //Cancel button action  
           }  
         });  
         builder.setCancelable(false);  
         builder.show();  
       }else {  
         if (manualCheck) {  
           Toast.makeText(activity, "No Update Available", Toast.LENGTH_SHORT).show();  
         }  
       }  
     }  
     @Override  
     protected void onPreExecute() {  
       super.onPreExecute();  
       if (manualCheck) {  
         progressDialog=new ProgressDialog(activity);  
         progressDialog.setMessage("Checking For Update.....");  
         progressDialog.setCancelable(false);  
         progressDialog.show();  
       }  
     }  
     @Override  
     protected String doInBackground(String... params) {  
       try {  
         //It retrieves the latest version by scraping the content of current version from play store at runtime  
         latestVersion = Jsoup.connect("https://play.google.com/store/apps/details?id=" + activity.getPackageName() + "&hl=it")  
             .timeout(30000)  
             .userAgent("Mozilla/5.0 (Windows; U; WindowsNT 5.1; en-US; rv1.8.1.6) Gecko/20070725 Firefox/2.0.0.6")  
             .referrer("http://www.google.com")  
             .get()  
             .select(".hAyfc .htlgb")  
             .get(7)  
             .ownText();  
         return latestVersion;  
       } catch (Exception e) {  
         return latestVersion;  
       }  
     }  
   }  
   public void checkForUpdate(boolean manualCheck)  
   {  
     new GetLatestVersion(manualCheck).execute();  
   }  
 }

Step-II
Add a library to your build.gradle(App level) file.

   implementation 'org.jsoup:jsoup:1.10.2'

Step-III
The last step is to copy that class and then write two lines of code.

 AppUpdateChecker appUpdateChecker=new AppUpdateChecker(this);  //pass the activity in constructure
 appUpdateChecker.checkForUpdate(false); //mannual check false here

Lets understand what is manual check

If manual check is true then
Manual check will be on a button click this will show the dialog as "Checking for update"