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.
Related
I'm using firebase with android to create a simple chat app. When the user chooses another user to chat with I want to check whether they've chatted together or not.
In onCreate() method I'm retrieving all the rooms that the current user used before, and I'm putting them in an arraylist called MyChatRooms<>.
Then I want to check each room to see the users of the room.
The problem is that the loop I'm using to iterate through rooms name is finishing before I'm able to retrieve any data from the database.
I know there's similar questions to mine, but none of the answers worked for me.
Here's the related code:
if (!MYChatRooms.isEmpty()) {
for (j = 0; j < MYChatRooms.size(); j++) {
roomref.child(MYChatRooms.get(j)).child("First User").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot1) {
if (!dataSnapshot1.getValue().toString().equals(Username) && dataSnapshot1.getValue().toString().equals(NUsername)) {
Users += dataSnapshot1.getValue().toString() + ",,, ";
} else if (dataSnapshot1.getValue().toString().equals(Username)) {
roomref.child(MYChatRooms.get(j)).child("Second User").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot2) {
if (dataSnapshot2.getValue().toString().equals(NUsername)) {
Users += dataSnapshot2.getValue().toString() + ",,, ";
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
I would suggest that you change the structure of your data. Imagine if a user has 100 chats that means your have to query 200 times to Firebase that of course does not look feasible.
What i would suggest is that your add a recentChat list in every user and whenever a user starts a new chat with someone you add the id of the second user to that list. That way you can track easily with whom the current user has interacted with.
It structure in firebase can look something like this:
User
recentChats
id of the other user
Try to change you database hierarchy or use firestore instead of real time database
Please check the following topic: https://firebase.google.com/docs/database/usage/optimize?
In my case, I had added and index column and limited the query in Firebase Rules.
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'm going through an Android app I've ported from iOS and trying to figure out the causes of any warnings I'm getting and get my code in line with Android Studio's lint.
So far, most of the "problems" have been pretty easy fixes, but I've got a warning with a particular Parse.com API function that has me stumped.
Here's the code:
private void loadData() {
ParseQuery query = ParseQuery.getQuery("someClass");
query.include("someProperty1");
query.include("someProperty2");
query.include("someProperty3");
query.orderByAscending("sequence");
query.whereEqualTo("owner", ParseUser.getCurrentUser());
// This next line causes the warning
query.findInBackground(new FindCallback<ParseObject>() {
#Override
public void done(List<ParseObject> items, ParseException e) {
if (e != null) {
// Error handling here
} else {
// Got query results here
}
}
});
}
The warning that is showing up is:
Unchecked call to 'findInBackground(FindCallback < T >)' as a member of raw type 'com.parse.ParseQuery'.
When you allow autocomplete to "fill out" a new FindCallback for you, you get this:
query.findInBackground(new FindCallback() {
#Override
public void done(List list, ParseException e) {
}
#Override
public void done(Object o, Throwable throwable) {
}
});
Well, that's annoying, because the actual results that are returned are a List of type ParseObject. So, I edited that code to my code above in order to streamline my code. The interesting thing is that even the autocomplete code has the same warning associated with it.
I think I understand to reason that this warning is generated, but I've attempted as best I can to specify my types. Is there something more I can do to make my code work? Or rather, given that I can't re-write Parse's code, how do I correctly fix this warning?
You just need to type your ParseQuery:
Replace ParseQuery query with ParseQuery<ParseObject> query
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.