Make the Plugin work unser ios10 and Android >= 23

plugin.xml

@@ -18,6 +18,8 @@
     <js-module src="www/Canvas2ImagePlugin.js" name="Canvas2ImagePlugin">
         <clobbers target="window.canvas2ImagePlugin" />
     </js-module>
+
+    <dependency id="cordova-plugin-compat" version="^1.0.0" />
 
     <!-- ios -->
     <platform name="ios">
@@ -32,6 +34,12 @@
 
         <source-file src="src/ios/Canvas2ImagePlugin.m"
             compiler-flags="-fno-objc-arc" />
+
+        <preference name="PHOTOLIBRARY_USAGE_DESCRIPTION" default=" " />
+        <config-file target="*-Info.plist" parent="NSPhotoLibraryUsageDescription">
+            <string>$PHOTOLIBRARY_USAGE_DESCRIPTION</string>
+        </config-file>
+
     </platform>
 
     <!-- android -->

src/android/Canvas2ImagePlugin.java

@@ -6,6 +6,7 @@
 
 import org.apache.cordova.CallbackContext;
 import org.apache.cordova.CordovaPlugin;
+import org.apache.cordova.PermissionHelper;
 
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -18,6 +19,9 @@
 import android.os.Environment;
 import android.util.Base64;
 import android.util.Log;
+import android.Manifest;
+import android.content.pm.PackageManager;
+
 
 /**
  * Canvas2ImagePlugin.java
@@ -30,6 +34,10 @@
  */
 public class Canvas2ImagePlugin extends CordovaPlugin {
 	public static final String ACTION = "saveImageDataToLibrary";
+    private final String WRITE_EXTERNAL_STORAGE = Manifest.permission.WRITE_EXTERNAL_STORAGE;
+    public static final int WRITE_PERM_REQUEST_CODE = 1;
+    private CallbackContext callbackContext;
+    private Bitmap bmp;
 
 	@Override
 	public boolean execute(String action, JSONArray data,
@@ -40,35 +48,48 @@ public boolean execute(String action, JSONArray data,
 			String base64 = data.optString(0);
 			if (base64.equals("")) // isEmpty() requires API level 9
 				callbackContext.error("Missing base64 string");
-			
+
 			// Create the bitmap from the base64 string
 			Log.d("Canvas2ImagePlugin", base64);
 			byte[] decodedString = Base64.decode(base64, Base64.DEFAULT);
 			Bitmap bmp = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
 			if (bmp == null) {
 				callbackContext.error("The image could not be decoded");
 			} else {
-
+
+                this.bmp = bmp;
+                this.callbackContext = callbackContext;
 				// Save the image
-				File imageFile = savePhoto(bmp);
-				if (imageFile == null)
-					callbackContext.error("Error while saving image");
-
-				// Update image gallery
-				scanPhoto(imageFile);
-
-				callbackContext.success(imageFile.toString());
+				askPermissionAndSave();
+
 			}
-			
+
 			return true;
 		} else {
 			return false;
 		}
 	}
 
-	private File savePhoto(Bitmap bmp) {
-		File retVal = null;
-
+    private void askPermissionAndSave() {
+
+        if (PermissionHelper.hasPermission(this, WRITE_EXTERNAL_STORAGE)) {
+            Log.d("SaveImage", "Permissions already granted, or Android version is lower than 6");
+            savePhoto();
+        } else {
+            Log.d("SaveImage", "Requesting permissions for WRITE_EXTERNAL_STORAGE");
+            PermissionHelper.requestPermission(this, WRITE_PERM_REQUEST_CODE, WRITE_EXTERNAL_STORAGE);
+        }
+	}
+
+
+	private void savePhoto() {
+
+
+		File image = null;
+
+        Bitmap bmp = this.bmp;
+        CallbackContext callbackContext = this.callbackContext;
+
 		try {
 			Calendar c = Calendar.getInstance();
 			String date = "" + c.get(Calendar.DAY_OF_MONTH)
@@ -91,36 +112,65 @@ private File savePhoto(Bitmap bmp) {
 			if (check >= 1) {
 				folder = Environment
 					.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
-				
+
 				if(!folder.exists()) {
 					folder.mkdirs();
 				}
 			} else {
 				folder = Environment.getExternalStorageDirectory();
 			}
-			
+
 			File imageFile = new File(folder, "c2i_" + date.toString() + ".png");
 
 			FileOutputStream out = new FileOutputStream(imageFile);
 			bmp.compress(Bitmap.CompressFormat.PNG, 100, out);
 			out.flush();
 			out.close();
 
-			retVal = imageFile;
+			image = imageFile;
 		} catch (Exception e) {
 			Log.e("Canvas2ImagePlugin", "An exception occured while saving image: "
 					+ e.toString());
 		}
-		return retVal;
+
+		if (image == null) {
+			callbackContext.error("Error while saving image");
+		} else {
+			// Update image gallery
+			scanPhoto(image);
+			callbackContext.success(image.toString());
+		}
+
+
 	}
-	
-	/* Invoke the system's media scanner to add your photo to the Media Provider's database, 
+
+	/* Invoke the system's media scanner to add your photo to the Media Provider's database,
 	 * making it available in the Android Gallery application and to other apps. */
 	private void scanPhoto(File imageFile)
 	{
 		Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
 	    Uri contentUri = Uri.fromFile(imageFile);
-	    mediaScanIntent.setData(contentUri);	      		  
+	    mediaScanIntent.setData(contentUri);
 	    cordova.getActivity().sendBroadcast(mediaScanIntent);
-	} 
+	}
+
+    /**
+     * Callback from PermissionHelper.requestPermission method
+     */
+    public void onRequestPermissionResult(int requestCode, String[] permissions, int[] grantResults) throws JSONException {
+        for (int r : grantResults) {
+            if (r == PackageManager.PERMISSION_DENIED) {
+                Log.d("SaveImage", "Permission not granted by the user");
+                callbackContext.error("Permissions denied");
+                return;
+            }
+        }
+
+        switch (requestCode) {
+            case WRITE_PERM_REQUEST_CODE:
+                Log.d("SaveImage", "User granted the permission for WRITE_EXTERNAL_STORAGE");
+				savePhoto();
+                break;
+        }
+    }
 }