I would like a populate a TextView in one of my fragments with a list of users who are attending a specific trip. On the Parse server, Trip contains a Parse Relation of users attending each instance of a Trip. The following method is in my Trip model class to retrieve a String list of the users' names.
public List<String> getMemberNames(){
final List members = new ArrayList<String>();
try{
ParseRelation<ParseUser> relation = getRelation(KEY_USER);
ParseQuery query = relation.getQuery();
query.findInBackground(new FindCallback<ParseUser>() {
#Override
public void done(List<ParseUser> parseUsers, ParseException e) {
for (ParseUser parseUser : parseUsers)
{
members.add(parseUser.getUsername());
}
Log.d("relation", members.toString());
}
});
}catch (Exception e){
e.printStackTrace();
}
return members;
}
In my adapter, I call this with the line:
viewHolder.tvMembers.setText(Arrays.toString(trip.getMemberNames().toArray()));
However, when I run the debugger, the list of members remains empty. Any advice on why this is? Is is not possible to query in the Trip model? I appreciate the help!
Related
I feel like I'm pretty close on this one, just need the last bit.
I have the following tables:
_User (standard Parse table)
Category (object Id, name)
Exercises (object Id, name, description, thumbnail, image, etc)
and UserFavourites which is where I store the user's preferred exercises
(objectId, user->users table, exercise->exercises table, category->category table)
I have writing to Parse using pointers just fine:
//create new parse object
ParseObject favouriteExercise = new ParseObject("UserFavourites");
//create pointers to the Exercise table and Category table
ParseObject exercise = ParseObject.createWithoutData("Exercises", mExerciseId);
ParseObject category = ParseObject.createWithoutData("Category", mCategoryId);
//put those pointers into the Userfavourites table and save
favouriteExercise.put("user",ParseUser.getCurrentUser());
favouriteExercise.put("exercise",exercise);
favouriteExercise.put("category",category);
//save
favouriteExercise.saveInBackground();
Now I'm trying to retrieve all the exercises a user has favourited and put them in to a listview by searching the table for any objects that match the user's pointer to the user's table:
ParseQuery<Exercises> query = ParseQuery.getQuery("UserFavourites");
final ParseObject user = ParseObject.createWithoutData(ParseUser.class, ParseUser.getCurrentUser().getObjectId());
query.whereEqualTo("user", user);
//call to parse.com to start the query
query.findInBackground(new FindCallback<Exercises>() {
#Override
public void done(List<Exercises> exercises, ParseException e) {
if (exercises != null) {
Toast.makeText(getApplicationContext(), "Favourites found, can't list yet", Toast.LENGTH_SHORT).show();
mAdapter.clear();
//add all the exercises to the list
mAdapter.addAll(exercises);
//sort the list alphabetically
mAdapter.sort(new Comparator<Exercises>() {
#Override
public int compare(Exercises exercises, Exercises t1) {
return exercises.getName().compareTo(t1.getName());
}
});
} else {
mNoFavourites.setVisibility(View.VISIBLE);
}
Where I'm stuck is when I run this I can see my query is working -> I am retrieving the 4 rows in UserFavourites that I favourited out of the table of 8, so it is filtering correctly, but the objects I'm getting aren't pointing to the exercises I want. They are just empty pointers.
Thanks.
Yes it will return only reference (Pointer). If you want actual object data call fetchInBackground
myObject.fetchInBackground(new GetCallback<ParseObject>() {
public void done(ParseObject object, ParseException e) {
if (e == null) {
// Success!
} else {
// Failure!
}
}
});
I figured it out based on the logic kishore jethava gave.
I queried the favorites table, then with the results I wanted (which pointed to another table) I cycled through each result and got the object it pointed to and added it to my ArrayList.
public void getFavourites() {
//set progress bar
setProgressBarIndeterminateVisibility(true);
ParseQuery<Exercises> query = ParseQuery.getQuery("UserFavourites");
final ParseObject user = ParseObject.createWithoutData(ParseUser.class, ParseUser.getCurrentUser().getObjectId());
query.whereEqualTo("user", user);
query.include("exercise");
//call to parse.com to start the query
query.findInBackground(new FindCallback<Exercises>() {
#Override
public void done(List<Exercises> objects, ParseException e) {
if (objects.size() != 0) {
for(ParseObject object : objects)
{
//for each pointer found, retrieve the object it points to
obj = object.getParseObject("exercise");
mAdapter.add((Exercises) obj);
}
});
}
} else {
mNoFavourites.setVisibility(View.VISIBLE);
}
//stop progress bar
setProgressBarIndeterminateVisibility(false);
}
});
}
Currently I am making an Android application with Android Studios and I am using Parse to handle the data. I want to be able send (put) data such as town names and info about that town (town_names would be a column and info would be another, there for each town_names would have its own info). I can do that with ease and it uploads to the Parse database. However, the part I can not seem to figure out is how to retrieve the data points I desire. I have code to retrieve data based off of an objectId shown below however that is not exactly what I want.
ParseQuery<ParseObject> query = ParseQuery.getQuery("userMessage");
query.getInBackground("KgsLojXPcq", new GetCallback<ParseObject>() {
public void done(ParseObject object, ParseException e) {
if (e == null) {
retrievedText = object.getString("info");
} else {
retrievedText = "No information.";
}
}
});
"userMessage" is the ParseObject I have created and "info" is the column I want to get text from. Instead of searching for an objectId ("KgsLojXPcq") is there a way to search for town_names? So then I could for example search the database for "New York" and "retrievedText" would be set to the info for New York.
ParseQuery
.getQuery("userMessage")
.whereEqualTo("town_names", "New York")
.getFirstInBackground(new GetCallback<ParseObject>() {
#Override
public void done(ParseObject object, ParseException e) {
if (e == null) {
retrievedText = object.getString("info");
} else {
retrievedText = "No information.";
}
}
});
I've question about way in which I should create query to get expected data.
I've MyObject (ParseObject) which has pointer to ParseUser (column named createdByPtr). In ParseUser I have custom column userGroupPtr.
Now I want to get all MyObject rows which are created by all users (createdByPtr) belongs to user group (userGroupPtr) to which belongs current logged user (ParseUser.CurrentUser()).
At this moment I have some kind of draft like this:
ParseQuery<MyObject> query = ParseQuery.getQuery(MyObject.class);
query.include("createdByPtr");
query.whereEqualTo("createdByPtr.userGroupPtr", ParseUser.getCurrentUser().get("userGroupPtr"));
query.orderByDescending("updatedAt");
query.findInBackground(new FindCallback<MyObject>() {
#Override
public void done(List<MyObject> results, ParseException e) {
....
}
});
I don't have idea how should I transform line:
query.whereEqualTo("createdByPtr.userGroupPtr", ParseUser.getCurrentUser().get("userGroupPtr"));
in to working constrain.
Any suggestions?
Try like this. I have tested and it works perfectly. see Relational Queries
ParseQuery<ParseUser> innerQuery = ParseUser.getQuery();
innerQuery.whereEqualTo("userGroupPtr","userGroupPtr"); //value of userGroupPtr
ParseQuery<ParseObject> query = ParseQuery.getQuery(MyObject.class);
query.whereMatchesQuery("createdByPtr", innerQuery);
query.findInBackground(new FindCallback<ParseObject>() {
public void done(List<ParseObject> objectList, ParseException e) {
if(e == null){
}else{
Log.e("Object", e.getMessage());
}
}
});
I've built an application that uses Parse. My application allows users to register, login and then post to a parse cloud database.
I have two Parse classes, one called User and one called Posts. User is made up of ObjectId, username and password, and Posts is made up of ObjectId, text and user. Of which user is a pointer to ObjectId within the User class.
I've created a method in my app called getData() which contains a ParseQuery, this queries the Posts class, selects the text field and includes the user field. The query then retrieves the data into a List and then loops through each row of the List, collecting the String from the text field and then adds it into a ListView on the UI using postList.add(textList.get(i).getString("text")); each time the program goes through the loop.Within the loop is another query, which queries the User class, selects the objectId field, I then add a constraint to the query to tell it to only retrieve data where the objectId field is equal to the user field within the Posts class(I think).
ParseQuery<ParseObject> queryUser = ParseQuery.getQuery("User");
queryUser.selectKeys(Arrays.asList("objectId"));
queryUser.whereEqualTo("objectId", textList.get(i).getString("user"));
Next I want to take the collected username data that the query retrieved, put it into a String and display it on screen in a toast. So basically the getData() method should collect all of the strings from the text field and the username of the user that posted it. The problem is that I'm unsure if i'm trying to go about this in the right way. My app throws an error when this piece of code is executed so I'm obviously doing something wrong.
java.lang.IllegalStateException: ParseObject has no data for this key. Call fetchIfNeeded() to get the data.
at com.parse.ParseObject.checkGetAccess(ParseObject.java:3235)
at com.parse.ParseObject.getString(ParseObject.java:2817)
at com.text.parse.MainActivity$3.done(MainActivity.java:186)
Code at line 186 : queryUser.whereEqualTo("objectId", textList.get(i).getString("user"));
My questions are:
1. Am I trying to do this in the right way?
2. Why am I receiving this error?
Code for getData() method:
public void getData() {
final ArrayList<String> postList = new ArrayList<String>();
final ArrayAdapter<String> listAdapter = new ArrayAdapter<String>(this, R.layout.listview_row, postList);
final ParseQuery<ParseObject> queryPosts = ParseQuery.getQuery("Posts");
queryPosts.selectKeys(Arrays.asList("text"));
queryPosts.include("user");
queryPosts.addDescendingOrder("createdAt");
queryPosts.setLimit(20);
queryPosts.findInBackground(new FindCallback<ParseObject>() {
#Override
public void done(List<ParseObject> textList, ParseException e) {
if (e == null) {
//query successful
for (int i = 0; i < textList.size(); i++) {
postList.add(textList.get(i).getString("text"));
ParseQuery<ParseObject> queryUser = ParseQuery.getQuery("User");
queryUser.selectKeys(Arrays.asList("objectId"));
queryUser.whereEqualTo("objectId", textList.get(i).getString("user"));
queryUser.setLimit(20);
queryUser.findInBackground(new FindCallback<ParseObject>() {
#Override
public void done(List<ParseObject> userList, ParseException e) {
if (e == null) {
String s = userList.get(0).getString("username").toString();
Toast.makeText(MainActivity.this, s, Toast.LENGTH_LONG).show();
}
else {
//query error
Toast.makeText(MainActivity.this, "query error: " + e, Toast.LENGTH_LONG).show();
}
}
});
}
lvText.setAdapter(listAdapter);
} else {
//query error
Toast.makeText(MainActivity.this, "query error: " + e, Toast.LENGTH_LONG).show();
}
}
});
}
Sorry for the long question. Any help would be greatly appreciated, thanks.
UPDATE:For anyone stuck with a similar problem, here's how I got it to work:
public void getData() {
final ArrayList<String> postList = new ArrayList<String>();
final ArrayAdapter<String> listAdapter = new ArrayAdapter<String>(this, R.layout.listview_row, postList);
final ParseQuery<ParseObject> queryPosts = ParseQuery.getQuery("Posts");
queryPosts.include("user");
queryPosts.addDescendingOrder("createdAt");
queryPosts.setLimit(20);
queryPosts.findInBackground(new FindCallback<ParseObject>() {
#Override
public void done(List<ParseObject> textList, ParseException e) {
if (e == null) {
//query successful
for (int i = 0; i < textList.size(); i++) {
postList.add(textList.get(i).getString("text"));
ParseObject po1 = textList.get(i);
ParseObject po2 = po1.getParseObject("user");
String username = po2.getString("username");
Toast.makeText(MainActivity.this, username, Toast.LENGTH_SHORT).show();
}
lvText.setAdapter(listAdapter);
} else {
//query error
Toast.makeText(MainActivity.this, "query error: " + e, Toast.LENGTH_LONG).show();
}
}
});
}
You simply include the column in the class you are querying that holds a pointer to another class, that then gives you access to all of the columns of data within the second class.
This method as shown is doing nothing useful:
ParseQuery<ParseObject> queryUser = ParseQuery.getQuery("User");
queryUser.selectKeys(Arrays.asList("objectId"));
queryUser.whereEqualTo("objectId", textList.get(i).getString("user"));
The selectKeys statement is telling it to only return the contents of the objectId column, which you are passing in to the whereEqualTo statement as a parameter... seems silly to run a query to get a value you already have!?. I would not user selectKeys until you think you need to optimise your queries. The only use this query would have is to let you know if the objectId is valid, since the query will return null if it isn't a valid objectId for a User.
I'm hoping that you want to get more information about the user, so if you remove selectKeys then the other columns will be returned.
The fact that fetchIfNeeded is throwing an exception on due to this line:
queryUser.whereEqualTo("objectId", textList.get(i).getString("user"));
That suggests that textList.get(i).getString("user") is not returning an objectId for a user. If that is instead returning a username as suggested by some of your other comments (not sure here), then you need to change that line of code to read:
queryUser.whereEqualTo("username", textList.get(i).getString("user"));
If there are some other questions you have, you'll need to be a bit more precise in your questions as it isn't really clear what you're asking at the moment.
My Class in parse is called "MyClass" and this one has several objects like
| ObjectId | Names | owners | users | (owners is a pointer of another class)
I want to do a query that gives me all of the names in my object "Names" that belong to the owner but, when I do this query i get this:
com.parse.ParseObject#41828fe0
com.parse.ParseObject#41829fdd
com.parse.ParseObject#4182aa28
my code is this
final ParseQuery query = new ParseQuery("MyClass");
query.whereEqualTo("owners", ParseUser.getCurrentUser());
query.findInBackground(new FindCallback() {
public void done( List<ParseObject> MyList, ParseException e) {
if (e == null) {
adapter = new ArrayAdapter<ParseObject>(MyActivity.this, android.R.layout.simple_list_item_1, MyList);
listDev.setAdapter(adapter);
}else{
//error
}
please help me how to do that query that gives me all of name that belong to the owner.
EDIT
I found a solution and is something like this.
ParseQuery<ParseObject> query = ParseQuery.getQuery("MyClass");
ParseUser user = ParseUser.getCurrentUser();
query.whereEqualTo("owners", user);
query.findInBackground(new FindCallback<ParseObject>() {
#Override
public void done(List<ParseObject> objects, com.parse.ParseException e) {
if (e == null) {
for (ParseObject parseObject : objects){
String task;
task= parseObject.get("owners").toString();
adapter.add(task);
adapter.notifyDataSetChanged();
}
} else {
// Something went wrong.
Toast.makeText(getActivity(),"Error: " + e.getMessage().toString(),Toast.LENGTH_SHORT).show();
}
}
});
Your real problem here is your ArrayAdapter. You would need a custom adapter if you want to use Parse objects as your data type. The built in adapter doesn't know how to use Parse objects and is outputting the object as a string for you. Instead you should do something like
arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, MyNamesList);
Where MyNamesList is of type String.
It's hard to help on your query without more information but you are getting Parse objects back, you just need to get the name out of them with something like
MyList.get(i).getString("name");
somewhere outside the query method
private ArrayList<YourObjectType> list;
public void done(List<ParseObject> objects, ParseException e) {
if (objects == null || objects.size() == 0) {
return; //no objects
}
list = new ArrayList<YourObjectType>();
for (int i = 0; i < objects.size(); i++) {
YourObjectType myObject = new YourObjectType();
ParseObject object = objects.get(i);
myObject.objectId = object.getObjectId();
myObject.names = object.get("Names");
myObject.owners = object.get("owners");
myObject.users = object.get("users");
list.add(myObject);
}
adapter = new ArrayAdapter<YourObjectType>(MyActivity.this,android.R.layout.simple_list_item_1, MyList);
listDev.setAdapter(adapter);
}
now set the list to your adapter
your adapter should be able to handle objects of your type, so i think you need to create a custom adapter, the one provided by the android sdk, won't do here
The solution is pretty easy, since you are getting com.parse.whatever, all u need to do is ParseUser user = ParseUser.getCurrentUser();
Then query.whereequalto("owner", user.getUsername());
The problem was, u where querying for currentUser instead of usernames.