I have an app which works with users, and offers the possibility to follow certain users, at the current user choice.
Unfortunately, I don't know how to modify data of a user which is not the current user. I have not seen anything like that stated in the Parse.com docs(or i missed).
I have a column in my database in "Users" class called "usersFollowed" and when the current user clicks "Follow" i want to add the current user to the "usersFollowed" list, but adding them like you will see in the following code does not work.
Follow user code:
dialog = ProgressDialog.show(context, "",
"Following...", true);
viewHolder.userFollow.setSelected(true);
viewHolder.userFollow.setText("FOLLOWING");
ParseQuery<ParseUser> userListQuery = ParseUser.getQuery();
userListQuery.whereEqualTo("screenName", parseUserList.get(position).get("screenName").toString());
userListQuery.findInBackground(new FindCallback<ParseUser>() {
#Override
public void done(List<ParseUser> parseObjects, ParseException e) {
parseUserFollowedList = new ArrayList<>();
if (parseObjects.get(0).getList("usersFollowed") == null) {
parseUserFollowedList.add(ParseUser.getCurrentUser());
parseObjects.get(0).addAll("usersFollowed", parseUserFollowedList);
} else {
parseUserFollowedList = parseObjects.get(0).getList("usersFollowed");
parseUserFollowedList.add(ParseUser.getCurrentUser());
parseObjects.get(0).addAll("usersFollowed", parseUserFollowedList);
}
parseObjects.get(0).saveInBackground(new SaveCallback() {
#Override
public void done(ParseException e) {
dialog.dismiss();
}
});
}
});
.saveInBackground does not work because it throws exception: Cannot save info for user that is not logged in".
Can anyone help me in how to do this?
Cheers!
Users may modify only their own data. But the idea of following can be implemented such that only the currentUser's record requires write access: If Jack chooses to follow Jill, then Jack writes to his "following" relation. This works as long as we don't try to represent "followedBy" in Jill's data (which can be achieved instead with a query).
Or consider that the User table represents the private relationship between a real person and your app. It might make better sense to model the idea of a user's public face with your own custom object, and model following relationships between those. I mention this idea elsewhere here and here.
Related
Right now I'm developing an android app, and I just started to work with Firebase.
My question is: How can I retrieve data from the firebase database, without use listeners ?
In my game, I'm saving the high scores of all the users, and I need to take the data from the database when user go into "leader-boards" page.
I saw some solutions, which is not good for my case.
One of them is:
mRef.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String value = dataSnapshot.getValue(String.class);
}
#Override
public void onCancelled(FirebaseError firebaseError) {
}
});
This solution is not good for me, because I cant afford to my app to go into the server every time high score of user is changing, because if I would have 20,000 people who playing at the same time, then the game will stuck.
so I cant use this listener, because it will make the game very slow.
My goal is to to find a way to change the high score, without alerting the other people who is currently playing the game, I mean that I need to update every user score for his own, and when user go to the "leader boards" page, only then I will go to the server.
what is the right solution here ?
Or can I use this listener in another way?
If my question is not clear, then ask me in the comment please.
Thank you !!
my lines:
public static void setUserHighScoreToServer(Context context,boolean isClassic,int scoreNum)
{
com.firebase.client.Firebase mRef;
mRef= new com.firebase.client.Firebase("...");
String name = InternalStorage.getUserName(context);
String classic = "";
if(isClassic)classic="Classic";
else classic="Arcade";
com.firebase.client.Firebase mRefChild = mRef.child(name+classic);
mRefChild.setValue(String.valueOf(scoreNum));
}
This is the OFFICIAL way to retrieve data once without listening for data changes.
// Add all scores in ref as rows
scores.addListenerForSingleValueEvent( new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot snapshot) {
for (DataSnapshot child : snapshot.getChildren()) {
...
}
}
}
more information here: https://firebase.google.com/docs/reference/android/com/google/firebase/database/DataSnapshot
If you don´t need to update on real time, you can always do a Rest api call to your database.
Just do a GET call to retrieve your data
https://[PROJECT_ID].firebaseio/[path].json
and you are good to go
You can also update or create new keys using rest api calls.
Hi I have the next problem:
I have 10 users registered in Parse,a user can have the role of Admin or Player.
I'm trying to get all the users first but when I tried, the query only return one (The current user).
How can I get all the users? And then how can I filter by Role?
I have the next code:
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.findInBackground(new FindCallback<ParseUser>() {
#Override
public void done(List<ParseUser> objects, ParseException e) {
if (e==null){
Log.i("OK","no problem");
}else{
Log.i("NOT OK","problem");
}
}
});
Honestly, for something as simple as this, it would be better for you not to use relations and separate classes at all and instead to simply add a string field to the User Class called "role." So go to your User class on Parse, add a new column of type String called "role" and then query it as follows.
ParseQuery<ParseUser> userQuery = ParseUser.getQuery();
userQuery.whereEqualTo("role", "admin");
userQuery.findInBackground(new FindCallback<ParseUser>() {
void done(List<ParseUser> results, ParseException e) {
// results has the list of users who are admins
}
});
You should check the ACL(readAccess) of each user. The user is without read access right. The other 9 user may not with public read, not specify the user's id, and the role is not equip access right.
As A.Vin's answer, if your user have more than 1 role, you can use array of strings.
On every launch my app loads fresh data from parse.com and pins all objects to use app without network requests like this^
public void pinKids() {
ParseQuery<ParseObject> query = ParseQuery.getQuery(ParseConstants.CLASS_KIDS);
query.whereEqualTo(ParseConstants.KEY_PARENT, currentUser);
query.findInBackground(new FindCallback<ParseObject>() {
public void done(final List<ParseObject> kidsList, ParseException e) {
if (e == null) {
ParseObject.unpinAllInBackground(ParseConstants.LABEL_KIDS, new DeleteCallback() {
#Override
public void done(ParseException e) {
ParseObject.pinAllInBackground(ParseConstants.LABEL_KIDS, kidsList, new SaveCallback() {
#Override
public void done(ParseException e) {
Log.d("Hello", "pinKids");
}
});
}
});
}
}
});
}
One of the columns in my class is an array of strings (it stores history messages). I found that my code doesn't refresh this array if that array was updated from the other device (the same user did something on the other device). The rest of the data (other columns) refresh without problems. But the array of strings stays as it was downloaded at first launch.
In parse.com dashboard I see that array is updated. But code doesn't download this array while all the other columns are downloaded correctly.
Let me say that when I update this array on device-1 the new data is stored on device-1 and on "parse.com" too. But it doesn't update on device-2.
Please help!
OK! I've solved it.
This problem is a bug of parse.com.
I've created an issue on parse's github.
So I found that my problem is a part of parse's bug.
So the answer is: replace all calls to getJSONArray(key) with getList(key). You might also need revert()/revert(key)
I am using the Android SDK of parse.com and have arrived at a peculiar problem.
From a fragment's onCreate:
Fetch an object from the server.
Pin it.
Fetch an object from the local datastore.
Here is a snippet of the code from the onCreate:
ParseObject myChatGroup = ParseObject.createWithoutData("ChatGroup", "mOJGWRiLPC");
myChatGroup.fetchInBackground(new GetCallback<ParseObject>() {
#Override
public void done(ParseObject chatGroup1, ParseException e) {
if (e == null) {
l.d("Fetched chat group: " + chatGroup1 + " from server");
chatGroup1.pinInBackground(new SaveCallback() {
#Override
public void done(ParseException e) {
if (e == null) {
l.d("Successfully pinned chat group");
ParseQuery<ParseObject> chatGroupParseQuery = new ParseQuery<>("ChatGroup");
chatGroupParseQuery.fromLocalDatastore()
.findInBackground(new FindCallback<ParseObject>() {
#Override
public void done(List<ParseObject> list, ParseException e) {
if (e == null) {
l.d("Found " + list.size() + " chat groups from local datastore");
} else {
e.printStackTrace();
}
}
});
} else {
e.printStackTrace();
}
}
});
} else {
e.printStackTrace();
}
}
});
Here is the log:
Fetched chat group: ChatGroup { objectId: mOJGWRiLPC, name: Admin } from server
Successfully pinned chat group
Found 0 chat groups from local datastore
But this doesn't make any sense! I just pinned an object so how can there be 0 objects in the local datastore. The code is so simple. What am I doing wrong? Could it be a bug with the SDK?
Any insight will be much appreciated I have been trying to find the issue for days now.
The Parse setup looks fine to me:
ParseObject.registerSubclass(ChatGroup.class);
Parse.enableLocalDatastore(this);
Parse.initialize(this, AppProps.properties.appId,
AppProps.properties.clientKey);
ParseUser.enableRevocableSessionInBackground();
Parse.setLogLevel(Parse.LOG_LEVEL_DEBUG);
Note:
It works fine when trying the same logic with the ParseUser object. And even other classes of mine like my Message which leads me to suspect that something is wrong with my ChatGroup class.
I have added two fields to my ChatGroup class on the parse.com data browser: name(String) and messages(Relation) with read and wrote access to a role called Admin.
When browsing to the actual parse db (using root access) I find that the database table (ParseObjects) does contain the row that I pinned. But somehow parse shows 0 results on querying it!
Parse doesn't seem to support ACLs on local datastore. So the easiest way to get around this issue is to do ignoreACLs() on the query -- assuming you do have roles/acls setup correctly on the server side, so whatever you have pinned locally should be OK permission-wise already.
I found the issue. It seems to be more like a bug with the Android SDK of parse. I narrowed it down to an issue with retrieving pinned objects with special ACLs using the Android SDK.
Initially, the object had the ACL such that only the role 'Admin' (that I created) can read and write. The funny thing is that the user with which I was testing the pinning and querying was an 'Admin'! But, when I changed the ACL such that public can read but only Admin can write, the problem was resolved!
My theory was that querying the local datastore behaves like a public query, no matter what role the user that is making the query has! But if any other theory explaining this would be appreciated. Luckily, in my case I need public read access, but this bug can be a huge downfall for some who need to have read access restricting ACLs! Hopefully parse.com will fix this issue soon.
This is quite a big issue! I am surprised that I couldn't find a question regarding this issue.
Yeah so basically you have to set ACL for current user and pin it before you pin the chat group.
ParseACL acl = new ParseACL();
acl.setReadAccess(ParseUser.getCurrentUser(), true);
ParseUser.getCurrentUser().setACL(acl);
ParseUser.getCurrentUser().pinInBackground();
I have a registered app on Parse with a signup/login system. Now I want to create an activity which grabs all the available users in the app and to display them one-by-one as a listview. Can someone tell me how can I do that?
Once you've setup your ListView's adapter you can call this whenever you need to update it's contents:
public void updateUsers() {
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.findInBackground(new FindCallback<ParseUser>() {
#Override
public void done(List<ParseUser> userObjects, ParseException error) {
if (userObjects != null) {
mUserAdapter.clear();
for (int i = 0; i < userObjects.size(); i++) {
mUserAdapter.add(userObjects.get(i));
}
}
}
});
}
That updates my adapter which is plugged into my ListView. If you have more than 100 users you want to return you'll need to up the limit as I hear that's the default (then you have to page the results, not sure how yet)
Side note: As far as I know you can't Subclass the ParseUser at the moment (you can, but you then can't use that as the object you're querying with using ParseUser.getQuery() (Which would normally be done by ParseUser.getQuery(MyCustomUserClass.class) if you were to query a customised object.