ANDROID RUNTIME PERMISSION:
What is runtime persmission and Need of Runtime Permission:
Android is a privilege separated operating system, i.e. each application in android is separated from another through a distinct id, and each application file / data is private to that application only. As a result an Android application can’t access any file or data outside its scope until and unless the file or data is shared with the application.
So, if an application needs anything outside its scope, then it should request for permission to the user. Android comes with a set of predefined permissions (System permissions) for certain tasks. Every application can request required permissions. For example, an application may declare that it requires network access. It can also define new permissions.
We can request permissions in two ways, either Single-Permission or Multi-permission
NOTE: Though we will request the permissions at runtime, we should add it to the Manifest also, so that the user will be prompted first time when going to use the permission, and then the system will remember user’s decision until user updates from the settings. We will start with the WRITE_EXTERNAL_STORAGE_PERMISSION. Add the storage permission to your AndroidManifest.xml just before the application tag.
eg: <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
SINGLE-PERMISSION:
Step 1: We checked for permission with checkSelfPermission() Method to check if the app already has permission to write on external storage. If it has then continue to else part, otherwise go to next step.
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
.......
}else{
......
}
Step 2: Here we used shouldShowRequestPermissionRationale() method to check if we should show the explanation for the permission or not, if this returns true then we showed an alert dialog with explanation, and on the positive button click we requested the permission. If shouldShowRequestPermissionRationale returns false then we requested permission straightforward.
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// Add Alert Dialog with positive and negative buttons
} else if (permissionStatus.getBoolean(Manifest.permission.WRITE_EXTERNAL_STORAGE,false)) {
//Show an alert dialog if Previously Permission Request was cancelled with 'Dont Ask Again',
// Redirect to Settings after showing Information about why you need the permission
}
else {
//just request the permission
}
Step 3: We have successfully requested permission so far. We just need to override the method onRequestPermissionsResult to receive the result. In that method first we checked the requested code with our declared constant requestCode == EXTERNAL_STORAGE_PERMISSION_CONSTANT then checked if length of grantResult is greater than 0, so that it contains the user’s decision, then we cheked if the value of 0 index of the grant result, if the value is equal to PackageManager.PERMISSION_GRANTED then it means that the user has authorised the permission and we can continue our work, otherwise in the else part we can again request for permission with explanation.
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == EXTERNAL_STORAGE_PERMISSION_CONSTANT) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//The External Storage Write Permission is granted to you... Continue your left job...
proceedAfterPermission();
} else {
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
//Show Information about why you need the permission
//Alert dialog
} else {
}
}
}
}
What is runtime persmission and Need of Runtime Permission:
Android is a privilege separated operating system, i.e. each application in android is separated from another through a distinct id, and each application file / data is private to that application only. As a result an Android application can’t access any file or data outside its scope until and unless the file or data is shared with the application.
So, if an application needs anything outside its scope, then it should request for permission to the user. Android comes with a set of predefined permissions (System permissions) for certain tasks. Every application can request required permissions. For example, an application may declare that it requires network access. It can also define new permissions.
We can request permissions in two ways, either Single-Permission or Multi-permission
NOTE: Though we will request the permissions at runtime, we should add it to the Manifest also, so that the user will be prompted first time when going to use the permission, and then the system will remember user’s decision until user updates from the settings. We will start with the WRITE_EXTERNAL_STORAGE_PERMISSION. Add the storage permission to your AndroidManifest.xml just before the application tag.
eg: <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
SINGLE-PERMISSION:
Step 1: We checked for permission with checkSelfPermission() Method to check if the app already has permission to write on external storage. If it has then continue to else part, otherwise go to next step.
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
.......
}else{
......
}
Step 2: Here we used shouldShowRequestPermissionRationale() method to check if we should show the explanation for the permission or not, if this returns true then we showed an alert dialog with explanation, and on the positive button click we requested the permission. If shouldShowRequestPermissionRationale returns false then we requested permission straightforward.
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// Add Alert Dialog with positive and negative buttons
} else if (permissionStatus.getBoolean(Manifest.permission.WRITE_EXTERNAL_STORAGE,false)) {
//Show an alert dialog if Previously Permission Request was cancelled with 'Dont Ask Again',
// Redirect to Settings after showing Information about why you need the permission
}
else {
//just request the permission
}
Step 3: We have successfully requested permission so far. We just need to override the method onRequestPermissionsResult to receive the result. In that method first we checked the requested code with our declared constant requestCode == EXTERNAL_STORAGE_PERMISSION_CONSTANT then checked if length of grantResult is greater than 0, so that it contains the user’s decision, then we cheked if the value of 0 index of the grant result, if the value is equal to PackageManager.PERMISSION_GRANTED then it means that the user has authorised the permission and we can continue our work, otherwise in the else part we can again request for permission with explanation.
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == EXTERNAL_STORAGE_PERMISSION_CONSTANT) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//The External Storage Write Permission is granted to you... Continue your left job...
proceedAfterPermission();
} else {
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
//Show Information about why you need the permission
//Alert dialog
} else {
}
}
}
}
Writer : Stuti Kasliwal
