Use of the checkSelfPermission in Android?

Question

I'm working on an app that needs multiple permissions from the user (location, external storage, camera and phone state) and if i put the requests one after the other, only one is asked to the user when i run the app, which is a problem :

if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        //ask for the location permission
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 123);

    }
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
        //ask for the location permission
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA);

    }
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED
            || ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED) {

        ActivityCompat.requestPermissions(this,
                PERMISSION_EXTERNAL, REQUEST_EXTERNAL_STORAGE);
    }

    if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE)!= PackageManager.PERMISSION_GRANTED)
    {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_PHONE_STATE}, REQUEST_PHONE_STATE);
    }

Having multiple test to create a string with all the permission requests needed being quite annoying to do, i tried just asking for the permissions without testing if they are granted with the checkSelfPermision method:

ActivityCompat.requestPermissions(this,
            new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.CAMERA,Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.READ_PHONE_STATE}, REQUEST_MULTIPLE);

And it works, it stacks all the different requests one after the other, if i rerun the app it doesn't ask again since the permissions have been granted, and if i manually remove one of the permissions, the app only asks for the one i've removed.

So if everything works perfectly without testing with checkSelfPermission, what's the use of this method? Is there a risk I missed or am not aware of ?

Answer 1

It allows you to see if you need to request permissions, which is useful if you want to display another screen to the user first explaining why you require those permissions.

Answer 2

@Waylan here is a very useful link or two and I will post some code that help you deal with which of the three ways the user can interface with what they selected. Namely Deny Allow and Do Not Ask Again links first

       if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
            //.... write file into storage ...
            System.out.println("SDK > BuildVersion TRUE");
        } else {
            requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 666);  // Comment 26
            System.out.println("go to requestPermissions");
        }
    }
    onLoad();
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {

    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {

        case 666: // Allowed was selected so Permission granted
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                Snackbar s = Snackbar.make(findViewById(android.R.id.content),"Permission Granted",Snackbar.LENGTH_LONG);
                View snackbarView = s.getView();
                TextView textView = (TextView) snackbarView.findViewById(android.support.design.R.id.snackbar_text);
                textView.setTextColor(Color.RED);
                textView.setTextSize(18);
                textView.setMaxLines(6);
                s.show();

                // do your work here

            } else if (Build.VERSION.SDK_INT >= 23 && !shouldShowRequestPermissionRationale(permissions[0])) {
                // User selected the Never Ask Again Option Change settings in app settings manually
                AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
                alertDialogBuilder.setTitle("Change Permissions in Settings");
                alertDialogBuilder
                        .setMessage("" +
                                "\nClick SETTINGS to Manually Set\n"+"Permissions to use Database Storage")
                        .setCancelable(false)
                        .setPositiveButton("SETTINGS", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                                Uri uri = Uri.fromParts("package", getPackageName(), null);
                                intent.setData(uri);
                                startActivityForResult(intent, 1000);     // Comment 3.
                            }
                        });

                AlertDialog alertDialog = alertDialogBuilder.create();
                alertDialog.show();

            } else {
                    // User selected Deny Dialog to EXIT App ==> OR <== RETRY to have a second chance to Allow Permissions
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED) {

                    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
                    alertDialogBuilder.setTitle("Second Chance");
                    alertDialogBuilder
                            .setMessage("Click RETRY to Set Permissions to Allow\n\n"+"Click EXIT to the Close App")
                            .setCancelable(false)
                            .setPositiveButton("RETRY", new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    //ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, Integer.parseInt(WRITE_EXTERNAL_STORAGE));
                                    Intent i = new Intent(MainActivity.this,MainActivity.class);
                                    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
                                    startActivity(i);
                                    }
                            })
                            .setNegativeButton("EXIT", new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    finish();
                                    dialog.cancel();
                                }
                            });
                    AlertDialog alertDialog = alertDialogBuilder.create();
                    alertDialog.show();
                }
            }
            break;
    }};