I play around with parse.com
For my little project I wanna download an Integer from Parse User Class (_User) in to a float.
How would I do that?
I tried with that code:
PFQuery *updatingQuery = [PFUser query];
[updatingQuery whereKey:#"objectId" equalTo:objectID];
[updatingQuery getFirstObjectInBackgroundWithBlock:^(PFObject * updating, NSError *error)
{
if (!error)
{
myFloat = [EXPData valueForKey:#"Data"];
}
}];
But I will become an error:
Assigning to 'float' from incompatible type 'id'
How can I retrieve a float?
Basically do the opposite of uploading after you retrieve the object:
PFQuery *updatingQuery = [PFUser query];
[updatingQuery whereKey:#"objectId" equalTo:objectID];
[updatingQuery getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) {
if (!error) {
int someNumber = object[#"IntegerClass"];
self.someLabel.text = [NSString stringWithFormat:#"%d", someNumber];
}
}];
Please read through Parse docs before asking something fundamental, or show that you've exercised some research. This is a fundamental basic of Parse query:
Here are some key sites you should bookmark if you plan on being a Parse developer:
https://parse.com/docs/ios/api/
https://www.parse.com/docs/ios/guide#push-notifications
https://www.parse.com/docs/ios/guide
https://parse.com/docs/downloads
Related
I have a Follower class where stores all following/follower relations of my app. However, when I was trying to retrieve the pointer of each PFUser, I can't get the attributes of each PFUser. Here is my code
PFQuery *query = [PFQuery queryWithClassName:#"Follower"];
[query whereKey:#"from" equalTo:[PFUser currentUser]];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error)
{
if (!error)
{
for(PFObject *o in objects)
{
PFUser *otherUser = (PFUser *)[o objectForKey:#"to"];
NSLog(#"%#",otherUser);
NSLog(#"%#",otherUser.username);
NSString *nickName = otherUser[#"nickName"];
cell.friendNameLabel.text = nickName;
NSLog(#"%#", otherUser[#"nickName"]);
//cell.friendUsrnameLabel.text = otherUser.username;
PFFile *imgFile = otherUser[#"profilePhoto"];
profileView.file = imgFile;
[profileView loadInBackground];
}
}
else
{
NSLog(#"error");
}
}];
when I tried to print every user, here is what i got from the console:
<PFUser: 0x7fc102ec9f70, objectId: GiOIGiNHjK, localId: (null)> {
}
so it didn't find the attributes of each user. Anyone knows the solution? Thanks.
Try to add this line before executing the query.
[query includeKey:#"to"];
I am making an app that registers users and allows them to add friends etc. So I have a LoginViewController where I retrieve the array of user's friends' objectIds when the login is successful. This function is called.
- (void) getFriendList
{
NSString * objectID = [PFUser currentUser].objectId;
NSLog(#"%#", objectID);
PFQuery *query = [PFUser query];
[query getObjectInBackgroundWithId:objectID block:^(PFObject *username, NSError *error) {
sharedClass.sharedInstance->retrievedFriends = username[#"friendsIds"];
friendListLoaded = YES;
[self getFriendsUsernames];
}];
Here i get an array object that contains object ids of all the friends this user has. As you can see when getFriendList is completed, it calls another function called GetFriendsUsernames. This function is supposed to retrieve profile pictures and usernames of those friends so I can populate the Friend List view later.
-(void) getFriendsUsernames
{
NSMutableArray * objectIDs = [[NSMutableArray alloc] initWithArray: sharedClass.sharedInstance->retrievedFriends];
PFQuery *query = [PFUser query];
int friendsCount = [objectIDs count];
for(int i = 0; i<=friendsCount;i++)
{
[query getObjectInBackgroundWithId:objectIDs[i] block:^(PFObject *username, NSError *error) {
[sharedClass.sharedInstance->friendsUsernames addObject:username[#"username"]];
[sharedClass.sharedInstance->friendsProfilePictures addObject:username[#"ProfilePicture"]];
}];
NSLog(#"%#", sharedClass.sharedInstance->friendsUsernames );
}
}
But this seems to be unsuccessful because nothing is logged on the console where it should log username of retrieved friend whenever one query gets finished. Am I doing this the right way? My array count is right so loop runs to the number of friends a user has. It also prints the username of first object in objectIds array if i put the logging command in the loop.
Your NSLog runs immediately after your query objects are queued for execution. Therefore, even if the code is running correctly (and I suspect it might not be), you'll never get the correct results you're after logged to the console.
If you have your Parse classes designed in a certain way, you could collapse this into 1 query by using the include method on PFQuery. This assumes that you've created an array of Pointers on your User object, named "friends". If you actually store the objectId (i.e., the string value) of each friend, this code won't work.
I'm not using Swift yet, so here's how I'd write this query in Objective-C:
- (void)getFriendList {
PFUser *currentUser = [PFUser currentUser];
PFQuery *query = [PFUser query];
[query whereKey:#"objectId" equalTo:currentUser.objectId];
[query includeKey:#"friends.username"];
[query includeKey:#"friends.ProfilePicture"];
[query getFirstObjectInBackgroundWithBlock:^(PFObject *user, NSError *error) {
if (error != nil) {
// Process the error
} else }
// You've got your user and the data you wanted
}
}];
}
Found it. Not the prettiest way out there but well it does what i want. gets me arrays of usernames and profile pictures of every objectID contained in array of friends.
NSMutableArray * objectIDs = [[NSMutableArray alloc] initWithArray: sharedClass.sharedInstance->retrievedFriends];
PFQuery *query = [PFUser query];
PFFile * imageFile;
//UIImage *profilePictureData;
int friendsCount = [objectIDs count];
for(int i = 0; i<friendsCount;i++)
{
PFObject * username = [query getObjectWithId:objectIDs[i]];
[sharedClass.sharedInstance->friendsUsernames addObject:username[#"username"]];
[sharedClass.sharedInstance->friendsEmailAdresses addObject:username[#"email"]];
//NSLog(#"%#",username[#"ProfilePicture"]);
imageFile = [username objectForKey:#"ProfilePicture"];
NSData *imageData = [imageFile getData];
UIImage *imageFromData = [UIImage imageWithData:imageData];
[sharedClass.sharedInstance->friendsProfilePictures addObject:imageFromData];
NSLog(#"%#", sharedClass.sharedInstance->friendsUsernames );
}
However simple it may be, I am still struggling to update PFObject data with
-(IBAction)postMessageTapped:(id)sender{
[self hideTextField:_messageTextField];
NSMutableArray *myNewMessageArray=[[NSMutableArray alloc]init];
[myNewMessageArray insertObject:_messageTextField.text atIndex:0];
[myNewMessageArray insertObject:[PFUser currentUser] atIndex:1];
PFQuery *query = [PFQuery queryWithClassName:ClassName];
[query getObjectInBackgroundWithId:currentId block:^(PFObject *object, NSError *error) {
object[messagingArray] = myNewMessageArray;
[object saveInBackground];
}];
}
The intent is to get message string from text field and current user name, and put that into an array which then updates the array that exists on the parse database. However,
Cannot do a comparison query for type: (null)
comes up when the user taps the button that posts the message.
Does anyone have a possible solution?
Edit:
PFQuery *query = [PFQuery queryWithClassName:ClassName];
[query whereKey:#"location" nearGeoPoint:locationOfSelectedPin];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!objects) {
NSLog(#"The getFirstObject request failed.");
} else {
for(PFObject *objectTest in objects){
NSLog(#"Successfully retrieved the object.");
objectTest[#"messagingArray"]=myNewMessageArray;
[objectTest saveInBackground];
}
}
}];
I have also tried using this to update my data, 'successfully retrieved object' gets printed 3 times, but then that is followed by three lines of 'error, object not found for update'.
Check where you are setting objectId - this error means it cannot get the object because you are passing a nil value to the database for lookup.
Here's a bit of code to handle the exception:
if (!currentId) {
NSLog(#"Your currentId object is nil! Check your assignment.");
}
else {
PFQuery *query = [PFQuery queryWithClassName:ClassName];
[query getObjectInBackgroundWithId:currentId block:^(PFObject *object, NSError *error) {
object[messagingArray] = myNewMessageArray;
[object saveInBackground];
}];
}
So this is my first time working with parse I have simple application which creates a user and allows them to sign in. I'm currently working on something that will allow them to fill in details about themselves using PFObjects, I don't have a problem with that. My issue is I need to get user specific data print out on an UILabel.
Here's my code creating a PFObject this works fine:
- (IBAction)saveProfile:(id)sender {
PFObject *profile = [PFObject objectWithClassName:#"Profile"];
[profile setObject: self.name.text forKey:#"name"];
[profile setObject:[PFUser currentUser] forKey:#"author"];
[profile saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
if (!error) {
NSLog(#"No Error");
}else NSLog(#"Yeah you got an error bro");
}];
}
Here's what I'm having an issue with my PFQuery:
PFQuery *query = [PFQuery queryWithClassName:#"Profile"];
[query whereKey:#"name" equalTo:[PFUser currentUser]];
[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) {
if (!error) {
NSLog(#"Success");
self.nameLabel.text = [NSString stringWithFormat:#"%#", query];
}
else {
NSLog(#"Fail");
}
}];
}
So basicly I want the user to enter their name have it save, and have that specific user's name print out on a label. This is as far as I got so, if you have any suggestions I'm all ears. Thanks!
Updated:
PFQuery *query = [PFQuery queryWithClassName:#"Profile"];
[query whereKey:#"author" equalTo:[PFUser currentUser]];
[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) {
if (!error) {
NSLog(#"Success");
self.nameLabel.text = object[#"name"];
}
else {
NSLog(#"Fails");
}
}];
}
Looks like you're setting the PFObject "name" key to self.name.text, but in your PFQuery you're querying the class and asking for values where "name" is equal to [PFUser currentUser]. You're setting the value one way then using a completely different value in an attempt to query the object; so getFirstObjectInBackgroundWithBlock isn't returning an object since there's no Profile object where "name" equals [PFUser currentUser].
I think you're confusing your "name" and "author" properties...
Edit (in response to your comment):
OK, so in saveProfile: you're creating a PFObject where you're setting "name" to the name string and "author" to the user's PFUser object. When you're using whereKey: to perform a query on this class in an effort to retrieve the object using getFirstObjectInBackgroundWithBlock:, the result returned to you will be the full first PFObject where the object associated with the key is the one specified in the whereKey: criteria. So you don't have to specify which key of the PFObject you want to read before performing getFirstObjectInBackgroundWithBlock:. The query returns the whole object -- name, author, etc.
So in order to access the returned PFObject's "name" within the query block, change:
self.nameLabel.text = [NSString stringWithFormat:#"%#", query];
to (dispatch_aync added to force the label change onto the main thread):
dispatch_async(dispatch_get_main_queue(),^{
self.nameLabel.text = object[#"name"];
});
This line
[query whereKey:#"name" equalTo:[PFUser currentUser]];
only works if the "name" column is a pointer or relation to the User class. If it is the username you're after, you need to use
[query whereKey:#"name" equalTo:[PFUser currentUser][#"username"]];
But why are you querying for the object you just saved?
Your last, updated example should work for your need.
You could fire up a query like the one below
PFQuery *query = [PFQuery queryWithClassName:#"Profile"];
NSString *nameStr = [NSString stringWithFormat:#"%#",[[PFUser currentUser]objectForKey:#"name"]];
[query whereKey:#"name" containsString:nameStr];
[query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error)
{
if (!error)
{
/*object contains all columns and you need only key to obtain value*/
nameLabel = [NSString stringWithFormat:#"%#",object[#"job"];
.
.
.
}
else
{
NSLog(#"Error: %#", [error localizedDescription]);
}
}];
Now you will have object of current user along with its all details. Also you could do a thing, i.e., At time of user filling up profile details save it in a dictionary as below :
NSDictionary *signupDetail = [NSDictionary dictionaryWithObjectsAndKeys:self.userRegisterTextField.text, #"username",
self.nameTextField.text, #"Name",
[ResponseDict objectForKey:#"sessionToken"] ,#"sessionToken",
[ResponseDict objectForKey:#"objectId"], #"objectId",
nil];
//ResponseDict is dictionary you get in response for successful signup.
Then you could store it using [NSUserDefaults standardUserDefaults] so you will have all info of user at one place and call it wherever needed.
I'm querying relation data on parse and I would like the objects to come back ordered by the date they were created. I've had this method work before but haven't been able to get an ordered query using relational data. The query return is in a random order. Thanks in advance! Here's my code:
PFQuery *postQuery = [PFQuery queryWithClassName:#"Post"];
[roomQuery whereKey:#"name" equalTo:self.postName];
NSError *error;
//done on main thread to have data for next query
NSArray *results = [postQuery findObjects:&error];
PFObject *post;
if ([results count]) {
post = [results objectAtIndex:0];
NSLog(#"results were found");
} else {
NSLog(#"results were not found");
}
PFRelation *commentsRelation = [#"Comments"];
[commentsRelation.query orderByAscending:#"createdAt"];
[commentsRelation.query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (error) {
NSLog(#"Error Fetching Comments: %#", error);
} else {
NSArray *comments = objects;
}
I'm a little confused by your code,
you create a "postQuery", and call it, but never use any of its data.
There's also a roomQuery that never seems to have been allocated, or used.
You're querying a specific post by its name. Are you controlling its name? If not, you should use id's
what is PFRelation commentsRelation = [#"Comments"];
Probably because it's just a snippet, this stuff is dealt with elsewhere; however, for my answer, I'm assuming that your "comments" field is an array of "Comment" class objects.
Option 1:
PFQuery * postQuery = [PFQuery queryWithClassName:#"Post"];
[postQuery whereKey:#"name" equalTo:self.postName];
// again, possibly an id field would be more reliable
// [postQuery whereKey:#"objectId" equalTo:self.postId];
[postQuery includeKey:#"Comments"];
PFObject * post = [postQuery getFirstObject];// no need to download all if you just want object at [0]
// this will contain your post and all of it's comments with only one api call
// unfortunately, it's not sorted, so you would have to run a sort.
NSArray * comments = [post[#"Comments"] sortedArrayUsingComparator: ^(id obj1, id obj2) {
return [obj1[#"createdAt" compare: obj2[#"createdAt"];
}];
Option 2:
Perhaps a better option is to rework your data structure and instead of associating the comments to the post, you could associate the post to the comments (as in the parse docs)
PFQuery * postQuery = [PFQuery queryWithClassName:#"Post"];
[postQuery whereKey:#"name" equalTo:self.postName];
// again, possibly an id field would be more reliable
// [postQuery whereKey:#"objectId" equalTo:self.postId];
PFQuery * commentQuery = [PFQuery queryWithClassName:#"Comment"];
[commentsQuery whereKey:#"parent" matchesQuery:postQuery]; // when creating a comment, set your post as its parent
[commentsQuery addOrderDescending:#"createdAt"]
[commentQuery findObjectsInBackgroundWithBlock:^(NSArray *comments, NSError *error) {
// comments now contains the comments for myPost
}];
Both of the above solutions avoid making extra unnecessary api calls (parse charges based on calls after all!).