prevent upload file type not an image

Author: duytq94

lib/chat.dart

@@ -124,12 +124,18 @@ class ChatScreenState extends State<ChatScreen> {
     StorageReference reference = FirebaseStorage.instance.ref().child(fileName);
     StorageUploadTask uploadTask = reference.putFile(imageFile);
     StorageTaskSnapshot storageTaskSnapshot = await uploadTask.onComplete;
-    imageUrl = await storageTaskSnapshot.ref.getDownloadURL();
-    setState(() {
-      isLoading = false;
+    storageTaskSnapshot.ref.getDownloadURL().then((downloadUrl) {
+      imageUrl = downloadUrl;
+      setState(() {
+        isLoading = false;
+        onSendMessage(imageUrl, 1);
+      });
+    }, onError: (err) {
+      setState(() {
+        isLoading = false;
+      });
+      Fluttertoast.showToast(msg: 'This file is not an image');
     });
-
-    onSendMessage(imageUrl, 1);
   }
 
   void onSendMessage(String content, int type) {

lib/settings.dart

@@ -84,23 +84,43 @@ class SettingsScreenState extends State<SettingsScreen> {
     String fileName = id;
     StorageReference reference = FirebaseStorage.instance.ref().child(fileName);
     StorageUploadTask uploadTask = reference.putFile(avatarImageFile);
-    StorageTaskSnapshot storageTaskSnapshot = await uploadTask.onComplete;
-    photoUrl = await storageTaskSnapshot.ref.getDownloadURL();
-    Firestore.instance
-        .collection('users')
-        .document(id)
-        .updateData({'nickname': nickname, 'aboutMe': aboutMe, 'photoUrl': photoUrl}).then((data) async {
-      await prefs.setString('photoUrl', photoUrl);
+    StorageTaskSnapshot storageTaskSnapshot;
+    uploadTask.onComplete.then((value) {
+      if (value.error == null) {
+        storageTaskSnapshot = value;
+        storageTaskSnapshot.ref.getDownloadURL().then((downloadUrl) {
+          photoUrl = downloadUrl;
+          Firestore.instance
+              .collection('users')
+              .document(id)
+              .updateData({'nickname': nickname, 'aboutMe': aboutMe, 'photoUrl': photoUrl}).then((data) async {
+            await prefs.setString('photoUrl', photoUrl);
+            setState(() {
+              isLoading = false;
+            });
+            Fluttertoast.showToast(msg: "Upload success");
+          }).catchError((err) {
+            setState(() {
+              isLoading = false;
+            });
+            Fluttertoast.showToast(msg: err.toString());
+          });
+        }, onError: (err) {
+          setState(() {
+            isLoading = false;
+          });
+          Fluttertoast.showToast(msg: 'This file is not an image');
+        });
+      } else {
+        setState(() {
+          isLoading = false;
+        });
+        Fluttertoast.showToast(msg: 'This file is not an image');
+      }
+    }, onError: (err) {
       setState(() {
         isLoading = false;
       });
-
-      Fluttertoast.showToast(msg: "Upload success");
-    }).catchError((err) {
-      setState(() {
-        isLoading = false;
-      });
-
       Fluttertoast.showToast(msg: err.toString());
     });
   }