I intend to write an iOS app to retrieve objects from Parse. The documentation shows you how to retrieve a particular object (with certain id). But I want to retrieve objects based on a particular field in the table.
How do I do it?
Something like this:
PFQuery *query = [PFQuery queryWithClassName:#"GameScore"];
[query whereKey:#"playerName" equalTo:#"Dan Stemkoski"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// The find succeeded.
NSLog(#"Successfully retrieved %d scores.", objects.count);
// Do something with the found objects
for (PFObject *object in objects) {
NSLog(#"%#", object.objectId);
}
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
https://www.parse.com/docs/ios_guide#queries-basic/iOS
Related
I am currently using the query whereKey:#"name" equalTo:#"Tom Coomer" and it is working.
However I would like to create an array of the usernames from the results.
How would I approach this?
Thanks
I am using Parse.com and Xcode to write the app.
Well, I assume you're saving your query results to an array, so what you want to do is this:
NSMutableArray *array = [NSMutableArray array]
for(PFUser *user in arrayFromQuery)
{
[array addObject:user.username];
}
What this does is traverse through your array and gets the username from each user and adds it to a new array.
If you want to fetch only the username from the Parse :
PFQuery *query = [PFQuery queryWithClassName:#"_User"];
[query selectKeys:#[#"username"]];
[query findObjectsInBackgroundWithBlock:^(NSArray *results, NSError *error) {
// objects in results will only contain the username fields
}];
result array contains the name of all user.
And if u want to fetch all records and then create a array of username:
PFQuery *query = [PFQuery queryWithClassName:#"_User"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// The find succeeded.
NSLog(#"Successfully retrieved %d user.", objects.count);
// Do something with the found objects
for (PFUser *object in objects)
{
[self.usernameArray addObject:object.username];
NSLog(#"%#", object.objectId);
}
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
where usernameArray is a NSMutableArray.
I'm trying to retrieve data from parse.com which i have already sent.
I'm using following code to send the data:
-(IBAction)msgSend:(id)sender {
PFObject *appMsg = [PFObject objectWithClassName:#"appMsg"];
appMsg[#"besked"] = msg.text;
[appMsg saveInBackground];
msg.text = #"";
}
And to get the data I'm trying this:
PFQuery *query = [PFQuery queryWithClassName:#"appMsg"];
[query getObjectInBackgroundWithId:#"*******" block:^(PFObject *appMsg, NSError *error) {
NSString *besked = appMsg[#"besked"];
msgRecieved.text = besked;
}];
At last I'm trying to display the data into a textView.
Im not really loading any data?
PFQuery *query = [PFQuery queryWithClassName:#"tempClass"];
[query orderByDescending:#"createdAt"];
query.limit =10;
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// Retrive values like below,object id is retrieved by objects.objectId
NSLog(#"Object values %#",[objects valueForKey:#"columnName"]);
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
I'm new to Parse and I'm trying to retrieve a list of friends for my current user, but my result is always nil.
Here's how my data is on the server:
Class User (auto-created when first user signed up using the PFUser class)
Inside the class User I have a field called "array_friends_id" which is an array and it contains multiple objectIds inside. This field already has an array in it with 1 string inside
Here's my code for iOS:
- (IBAction)button_login:(id)sender
{
[PFUser logInWithUsernameInBackground:[textField_username text]
password:[textField_password text]
block:^(PFUser *user, NSError *error)
{
if (!error)
{
NSLog(#"logged in!");
// find friends
PFQuery *query = [PFQuery queryWithClassName:#"Users"];
[query whereKey:#"user" equalTo:[PFUser currentUser]];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error)
{
NSLog(#"objects = %#", objects);
}
}];
}
else
{
NSLog(#"can't login. Error = %# %#", error, [error userInfo]);
}
}];
}
My idea is to allow the user to log into the app, and as soon as the user logs in I want to retrieve his list of friends, even before pushing to the next view controller.
What am I doing wrong?
This is how I query in Parse,
PFQuery *query = [PFUser query];
[query orderByAscending:#"username"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (error) {
NSString *errorString = [error userInfo][#"error"];
NSLog(#"Log %#", errorString);
}
else {
// all good
}
}];
I am stuck for a long time with boolean show/hide image. Image is placed in my cell. Only boolean is needed. Could anyone tell me what I am doing wrong?
PFQuery *query = [PFQuery queryWithClassName:#"Parseclass"];
[query whereKey:#"imagebool" equalTo:[NSNumber numberWithBool:[NSNumber numberWithBool:YES]];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
cell.discounts.hidden =YES;
}else{
cell.discounts.hidden =NO;
}
}];
EDIT:
PFQuery *query = [PFQuery queryWithClassName:#"parsecell"];
[query whereKey:#"imagebool" equalTo:[NSNumber numberWithBool:YES]];
[query findObjectsInBackgroundWithBlock:^(NSArray *object, NSError *error)
{
if (!error)
{
NSLog(#"Successfully retrieved: %#", object);
NSDictionary *dict = [object objectAtIndex:0];
BOOL boolean;
boolean = [[dict objectForKey:#"imagebool"] boolValue];
if(boolean==YES)
{
NSLog(#"BOOL1: %hhd", boolean);
cell.discounts.hidden = YES;
} else {
cell.discounts.hidden = NO;
NSLog(#"BOOL2: %hhd", boolean);
}
}
else
{
NSLog(#"Error: %#", [error localizedDescription]);
}
}];
Change below stuff :-
[NSNumber numberWithBool:[NSNumber numberWithBool:YES]] //No need for this double encoding.
Simple go with [NSNumber numberWithBool: YES].
Also
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error)
{
if (!error && objects) //Checking for object's just to know if your getting any result for condition that you provided in query.
{
//Then hide your image.
}else{
//Or show your image.
}
}];
Just in case if your storing image on parse and check if image is nil or stored. Then just simple call for column that is storing image and no boolean check condition. That way you would get object's and know which row/column in your app is to show/hide image. Also in that object you will get image and provide it in your app and no need to store on local memory of phone. Anything else do let me know.
UPDATE:-
As you will get the object(array).
[query findObjectsInBackgroundWithBlock:^(NSArray *object, NSError *error)
{
if (!error)
{
NSLog(#"Successfully retrieved: %#", object);
NSDictionary *dict = [object objectAtIndex:0];
//Now with dict you could simply check for key(boolean) and then depending on YES/NO ,you could hide/Show the image.
}
else
{
NSLog(#"Error: %#", [error localizedDescription]);
}
}];
Hope this might help you.
Two problems I see with your code:
For some reason you're double encoding YES, i.e. [NSNumber numberWithBool:[NSNumber numberWithBool:YES]], probably won't break things, but fix it
In the block you're checking for an error, but you're not checking the objects returned. The array will come back empty if nothing matched the query, add a check for objects.count > 0
I have looked ALL over the internet and found nothing, Please help me. Im trying to figure out how I can display a username from parse in my table view (detailTextLabel). When I do the code below my app only shows the PFUser Id not the username. It will display: <PFUser:H2AhEbYGal:(null)> { but I'm trying to display the username of that post.
Heres me saving the object:
PFUser *user = [PFUser currentUser];
PFObject *quoteNew = [PFObject objectWithClassName:#"New"];
quoteNew[#"author"] = user;
[quoteNew setObject:[[self quoteText] text] forKey:#"quoteText"];
Here is me trying to retrieve the user in a PFQuery:
PFQuery *query = [PFQuery queryWithClassName:#"New"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// The find succeeded. The first 100 objects are available in objects'
[query includeKey:#"author"];
// PFObject *testObject = [query findObjects];
// PFUser *testUser = [testObject objectForKey:#"author"];
// NSLog(#"username: %#",testUser.username);
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
Here is me trying to display it:
cell.detailTextLabel.text = [NSString stringWithFormat:#"%#: %#",[object objectForKey:#"author"],[dateFormat stringFromDate:updated]];
You can just worry about [object objectForKey:#"author"] in that cell.detailTextLabel.text code.
This:
PFQuery *query = [PFQuery queryWithClassName:#"New"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// The find succeeded. The first 100 objects are available in objects'
[query includeKey:#"author"];
// PFObject *testObject = [query findObjects];
// PFUser *testUser = [testObject objectForKey:#"author"];
// NSLog(#"username: %#",testUser.username);
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
Should be:
PFQuery *query = [PFQuery queryWithClassName:#"New"];
// BEFORE WE QUERY
[query includeKey:#"author"];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// Get your objects here
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
And this:
cell.detailTextLabel.text = [NSString stringWithFormat:#"%#: %#",[object objectForKey:#"author"],[dateFormat stringFromDate:updated]];
Should be:
PFUser *userToDisplay = object[#"author"];
cell.detailTextLabel.text = [NSString stringWithFormat:#"%#: %#",userToDisplay.username,[dateFormat stringFromDate:updated]];
Because, as it stands, problem 1 is you're saying to include the author AFTER you have already queried parse. Problem 2 is that you're trying to display the whole user, you need to get the user, and then print the username value.