Obj-C: Check if object exists in NSMutableArray? - ios

I'm trying to check if NSString 'testing' (47) exists inside of my NSMutableArray 'self.checkfriendData'. I'm using the code below, though after logging my if statement it appears as though it's never executed (even though the statement is true - see console data below, uid = 47, and thus hiding my object should fire?) Any idea as to why this isn't working? Help is much appreciated!
ViewController.m
NSMutableDictionary *viewParams3 = [NSMutableDictionary new];
[viewParams3 setValue:#"accepted_friends" forKey:#"view_name"];
[DIOSView viewGet:viewParams3 success:^(AFHTTPRequestOperation *operation, id responseObject) {
self.checkfriendData = (NSMutableArray *)responseObject;
NSString *testing = #"47";
NSArray *friendorNo = self.checkfriendData;
if ([friendorNo containsObject:testing]) // YES
{
self.addFriend.hidden = YES;
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
}];
Here's what's inside self.checkfriendData:
2017-05-18 19:36:07.266529-0700 This is the friend data check (
{
body = "My name is Britt";
friendphoto = "/sites/default/files/stored/x.jpg";
"node_title" = "Britt";
uid = 47;
}
)

It appears that your NSArray contains NSDictionarys and you are asking if the array contains an NSString. The answer will always be no as the array doesn't directly contain any NSStrings.
If you want to search for the uid of 47 you will have to iterate over the array and check the uid key of each NSDictionary for the value 47.
The code for this would look something like:
for (NSDictionary *dict in friendorNo) {
if ([dict[#"uid"] isEqualToString:testing]) {
self.addFriend.hidden = YES;
}
}

Related

Best way to fetch child and parent objects with Parse Server in iOS

I'm trying out the "Sample Blog App" on Parse Server for iOS and cannot figure out what is the smartes way to fetch all child objects of another class (together with the parent objects).
The "Sample Blog App" (which creates automatically when you create a new account) contains the classes Comment and Post. The Comment class contains a relation to the Post class as shown below (from the dashboard), but there is no relation in the opposite direction.
Now, I want to fetch all posts and all the comments related to each post. The code below does that, but I'm assuming there must be a smarter way...? If you know how, please share. Thanks in advance!
- (void)fetchPosts {
NSString *commentsKey = #"comments";
NSString *postKey = #"post";
PFQuery *query = [PFQuery queryWithClassName:#"Comment"];
[query includeKey:postKey];
[query findObjectsInBackgroundWithBlock:^(NSArray * _Nullable objects, NSError * _Nullable error) {
if (error == nil) {
NSMutableArray *array = [[NSMutableArray alloc]init];
for (PFObject *comment in objects) {
PFObject *post = [comment objectForKey:postKey];
NSDictionary *existingPostDict = [[array filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"%K = %#", #"post.objectId", post.objectId]] firstObject];
if (existingPostDict) {
// update comments
NSArray *comments = [[existingPostDict objectForKey:commentsKey] arrayByAddingObject:comment];
// create new dictionary and replace the old one
NSDictionary *newPostDict = [[NSDictionary alloc]initWithObjectsAndKeys:[existingPostDict objectForKey:postKey], postKey, comments, commentsKey, nil];
[array replaceObjectAtIndex:[array indexOfObject:existingPostDict] withObject:newPostDict];
}
else {
// first post, create a new dict
NSDictionary *newPostDict = [[NSDictionary alloc]initWithObjectsAndKeys:post, postKey, #[comment], commentsKey, nil];
[array addObject:newPostDict];
}
}
self.posts = array; // assuming: #property (nonatomic, strong) NSArray *posts;
}
else {
NSLog(#"Error fetching posts: %#", error.localizedDescription);
}
}];
}
Instead of using include on your query you should use whereKey:equals: and pass the post object as the second argument. This will filter and return only the comment objects that contain that have that post as their value for post
One problem I see with your query is that there is a possibility this will not fetch every post in the database. If a post has 0 comments, none of the Comment objects will have a reference to it and thus you will not receive it.
Therefore you should actually do a query on "Post" and in its completion do a query on "Comment". This way you will not miss any posts with 0 comments. When you do this, you will not need to include the "post" key in the Comment query. This has multiple benefits.
First, each include is also another query for that object. So each new Comment object will create another query in the backend. You will get rid of this automatically.
Second, for a "Post" with multiple comments, you will be querying for the same post multiple times and that same post will be returned multiple times which consumes unnecessary bandwidth.
After getting Posts and Comments separately just combine them.
Apart from that I would do the combining like so which I find more readable but that is just personal preference.
- (void)fetchPosts {
NSString *commentsKey = #"comments";
NSString *postKey = #"post";
PFQuery *query = [PFQuery queryWithClassName:#"Comment"];
[query includeKey:postKey];
[query findObjectsInBackgroundWithBlock:^(NSArray * _Nullable objects, NSError * _Nullable error) {
if (error == nil) {
NSMutableArray *array = [[NSMutableArray alloc]init];
NSMutableDictionary *d = [NSMutableDictionary dictionary];
for (PFObject *comment in objects) {
PFObject *post = [comment objectForKey:postKey];
if (d[post.objectId]) {
[d[post.objectId][commentsKey] addObject:comment];
}
else{
d[post.objectId] = [NSMutableDictionary dictionary];
d[post.objectId][postKey]=post;
d[post.objectId][commentsKey] = [NSMutableArray arrayWithObject:comment];
}
}
for (NSString *key in [d allKeys]) {
[array addObject:d[key]];
}
self.posts = array; // assuming: #property (nonatomic, strong) NSArray *posts;
}
else {
NSLog(#"Error fetching posts: %#", error.localizedDescription);
}
}];
}
This is how I did it, using findObjectsInBackground together with continueWithSuccessBlock: methods (for better error handling one can choose continueWithBlock: instead):
- (void)fetchPosts {
/**
create "post" and "comment" queries and use a BFTask-method from
Bolts.framework to chain downloading tasks together (bundled with Parse SDK)
*/
NSMutableArray *posts = [NSMutableArray new];
PFQuery *postQuery = [PFQuery queryWithClassName:#"Post"];
[[[postQuery findObjectsInBackground] continueWithSuccessBlock:^id(BFTask * task) {
[posts addObjectsFromArray:task.result];
PFQuery *commentsQuery = [PFQuery queryWithClassName:#"Comment"];
return [commentsQuery findObjectsInBackground];
}] continueWithSuccessBlock:^id(BFTask * task) {
/**
loop through posts and filter out comments with the same objectId in post,
then create a dictionary with post and related comments. done! :)
*/
NSMutableArray *postsAndComments = [NSMutableArray new];
for (PFObject *post in posts) {
NSArray *comments = [task.result filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:#"%K == %#", #"post.objectId", post.objectId]];
[postsAndComments addObject:#{#"post":post, #"comments":comments}];
}
/**
note: BFTask-blocks not running in main thread!
*/
dispatch_async(dispatch_get_main_queue(), ^{
self.posts = postsAndComments; // assuming: #property (nonatomic, strong) NSArray *posts;
});
return nil;
}];
}

JSON Data retrieved, how do I display it in my label?

I've retrieved data to my iOS app from my Drupal database using the below code:
.h
#property (strong, nonatomic) NSMutableArray *userData;
.m
self.userData = [NSMutableArray new];
NSMutableDictionary *viewParams = [NSMutableDictionary new];
[viewParams setValue:#"u000" forKey:#"view_name"];
[DIOSView viewGet:viewParams success:^(AFHTTPRequestOperation *operation, id responseObject) {
self.userData = [responseObject mutableCopy];
NSLog(#"%#",self.userData);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"Failure: %#", [error localizedDescription]);
}];
self.userData = [[NSMutableArray alloc] init];
self.userBio.text = self.userData[0][#"userbio"];
self.userData is populated, so I know my data has successfully been returned. Does anyone know how I would display the JSON returned field in a UIlabel? I'm just not sure how I would write this line of code (newb, sorry). My field name is userbio.
Here's how the data structure is returned (incase it's of any use):
UPDATE: NSLog(#"userData = %#", self.userData); returns this in the console:
2015-10-25 11:22:06.601 [7605:2738034]
userData = (
> {
> userbio = "No user bio available at this time.";
> "users_name" = "<a href=\"/user/20\" title=\"View user profile.\" class=\"username\" xml:lang=\"\" about=\"/user/20\"
> typeof=\"sioc:UserAccount\" property=\"foaf:name\"
> datatype=\"\">Brittany</a>";
> },
If it's an NSDictionary the code would look like this:
self.myLabelName.text = self.userData[#"userbio"];
If it's an NSArray of NSDictionaries it would look like:
self.myLabelName.text = [self.userData firstObject][#"userbio"];
That's assuming that the array contains only one dictionary, otherwise you would have to access each element: self.userData[0], self.userData[1], etc.

Add Key and Values from NSDictionary to NSMutableArray

I have an NSMutableArray with keys UserID and UserName.
I also have an NSDictionary with keys UserID and UserScore.
How do I add the key and values for UserScore from the NSDictionary to the NSMutableArray so that the UserName and UserScore represent the same UserID?
NSMutableArray:
UserID = 123,
UserName = JohnP
NSDictionary:
UserID = 123,
UserScore = 100
Desired output as NSMutableArray:
UserID = 123,
UserName = JohnP,
UserScore = 100
Below is how I retrieve data into the NSMutableArray using Parse and then grab data to a label:
[FBRequestConnection startWithGraphPath:#"/me/friends"
parameters:nil
HTTPMethod:#"GET"
completionHandler:^(
FBRequestConnection *connection,
id result,
NSError *error
) {
FacebookFriends = [result objectForKey:#"data"];
}];
NSString *friendname = [[NSString alloc] initWithFormat:#"%#",[[FacebookFriends objectAtIndex:indexPath.row] objectForKey:#"name"]];
I think you really just wanna use an NSMutableDictionary which is made to store value-key pairs.
You can give your mutable dictionary values from your other dictionary simply by pointing to its key-value (objectForKey).
It looks to me like you want to combine two dictionaries into one:
NSDictionary *dict1 = ...;
NSDictionary *dict2 = ...;
NSMutableDictionary *combined = [NSMutableDictionary new];
NSNumber *userid = dict1[#"UserID"];
NSAssert(userid, #"UserID missing from dict1");
NSAssert([userid isEqualToString:dict2[#"UserID"]], #"Mismatched UserIDs");
NSString *username = dict1[#"UserName"];
NSAssert(username, #"Username missing from dict1");
NSNumber *score = dict2[#"UserScore"];
NSAssert(score, #"Score missing from dict2");
combined[#"UserID"] = userid;
combined[#"UserName"] = username;
combined[#"UserScore"] = score;
However I also suspect you have an array of dictionaries. If so, let me know.

NSArray arrayByAddingObjectsFromArray

I have this code, but when I log the mediaDictionaryArray, I get null. Does the receiver array have to be initialized with a value first or can I add objects to an empty array? Does [NSArray array] vs. [[NSArray alloc]init] have anything to do with it?
Adding dictionary from API call that happens i times. Asynch call will return the dictionary - can't be sure if NSMutableArray will work in catchJSONArray since asynch nature of call will make the array of indeterminate size which will make it hard to use later on.
Updated with relevant bit.
for (int i = 0; i<[array count]; i++) {
NSString *getString = array[i];
NSLog(#"getstring %#", getString);
[client GET:getString parameters:nil success:^(NSURLSessionDataTask *task, id responseObject) {
{
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)task.response;
if (httpResponse.statusCode == 200) {
dispatch_async(dispatch_get_main_queue(), ^{
_locationMediaArray = (NSArray*)responseObject[#"data"];
[self catchJSONArray:_locationMediaArray];
then here is method with the array issue
-(void)catchJSONArray:(NSArray*)array{
NSArray *catchJSONArray = [NSArray array];
_mediaDictionaryArray = [catchJSONArray arrayByAddingObjectsFromArray:array];
NSLog(#"mediaDictionaryArray %#", _mediaDictionaryArray);
}
arrayByAddingObjectsFromArray returns a new array containing your objects, as an NSArray can not be changed once created.
If you want to change an existing array, you should be using an NSMutableArray.
The best way you could do this is:
_mediaDictionaryArray=[NSArray arrayWithArray:otherArray];
That will create a new array with the contents of otherArray and assign it to _mediaDictionary.
No need to alloc init your array just pass the refrence of your other array. If
_mediaDictionaryArray is mutable array then use below:-
_mediaDictionaryArray=[array mutableCopy];
If it is non mutable array then use below
_mediaDictionaryArray=[array copy];

-[__NSCFArray objectForKeyedSubscript:] error?

I'm trying to get the data from a JSON response object in my iOS app after I log in. I keep getting this error though.
Error:
'NSInvalidArgumentException', reason: '-[__NSCFArray objectForKeyedSubscript:]: unrecognized selector sent to instance 0x8fc29b0'
Here is my code for the request, I'm using AFNetworking:
self.operation = [manager GET:urlString parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSDictionary *JSON = (NSDictionary *)responseObject;
NSDictionary *user = JSON[#"user"];
NSString *token = user[#"auth_token"];
NSString *userID = user[#"id"];
// NSString *avatarURL = user[#"avatar_url"];
// weakSelf.credentialStore.avatarURL = avatarURL;
weakSelf.credentialStore.authToken = token;
weakSelf.credentialStore.userId = userID;
weakSelf.credentialStore.username = self.usernameField.text;
weakSelf.credentialStore.password = self.passwordField.text;
[SVProgressHUD dismiss];
[self dismissViewControllerAnimated:YES completion:nil];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
if (operation.isCancelled) {
return;
}
[SVProgressHUD showErrorWithStatus:#"Login Failed"];
NSLog(#"%#", error);
}];
What the JSON response object looks like logged:
<__NSCFArray 0x8cac0b0>(
{
user = {
"auth_token" = b3a18e0fb278739649a23f0ae325fee1e29fe5d6;
email = "jack#jack.com";
id = 1;
username = jack;
};
}
)
I'm converting the array to a Dictionary using pointers like this:
EDIT: As pointed out in the comments incase anyone else stumbles across this with limited knowledge in iOS. I'm casting here not converting. See the answers for a full explanation.
NSDictionary *JSON = (NSDictionary *)responseObject;
I'm new to iOS, apologies if problem is obvious.
Thanks for any help.
The "conversion" you do is not doing any conversion, it's a cast. This simply tells the compiler to ignore the type it knows for this object and act as if it's the type you pass it.
Looking at the output you have, you don't get a dictionary back, but an array of dictionaries with a single dictionary. To get to the first dictionary you can use this instead of the cast:
NSDictionary *JSON = [responseObject objectAtIndex:0];
Note that since you get your data from a web service, you should probably also check if the contents you get are what you expect.
You say:
I'm converting the array to a Dictionary using pointers like this:
But that is not what you are doing. You are casting it, but the underlying object is still an array.
From the JSON response you can see that those JSON is constructed as an array with a single element which is a dictionary. You can get to the dictionary by calling [responseObject firstObject];. Of course, so that you don't get error going in the other direction, you should check how the input is constructed before calling any array or dictionary specific methods on the response object.
You have to convert your self but do not use casting.
Or, this is the code to detect if a json object is an array or dictionary
NSError *jsonError = nil;
id jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&jsonError];
if ([jsonObject isKindOfClass:[NSArray class]]) {
NSLog(#"its an array!");
NSArray *jsonArray = (NSArray *)jsonObject;
NSLog(#"jsonArray - %#",jsonArray);
}
else {
NSLog(#"its probably a dictionary");
NSDictionary *jsonDictionary = (NSDictionary *)jsonObject;
NSLog(#"jsonDictionary - %#",jsonDictionary);
}

Resources