At the moment I have an app that is using Firebase database to store the users:
Name
School
Subject
Within three separate textfields.
Right now I've managed to allow the user to enter his details within these three text fields and hit a button labeled update, which then sends the data to my firebase console.
This means that the user can enter their details, hit update and see them while they are logged in. however as soon as they logout and login again the textfields are blank, despite the fact that firebase has the info stored on its server.
I've been playing around all day trying to get it to work but to no avail.
Here we have the firebase reference and auth:
self.rootRef = [[FIRDatabase database] reference];
self.user = [FIRAuth auth].currentUser;
And the update button code that sends the users info to the firebase database:
- (IBAction)didTapEditProfile:(id)sender {
if (![_textFieldOne.text isEqual: #""]) {
NSString *item = _textFieldOne.text;
[[[[_rootRef child:#"users"] child:_user.uid] child:#"Name"] setValue:item];
}
if (![_textFieldTwo.text isEqual: #""]) {
NSString *itemTwo = _textFieldTwo.text;
[[[[_rootRef child:#"users"] child:_user.uid] child:#"School"] setValue:itemTwo];
}
if (![_textFieldThree.text isEqual: #""]) {
NSString *itemThree = _textFieldThree.text;
[[[[_rootRef child:#"users"] child:_user.uid] child:#"Subject"] setValue:itemThree];
}
}
The problem i'm having is with retrieving the data within the code below which is situated in the viewDidAppear:
[[_rootRef child:#"users"] observeEventType:FIRDataEventTypeValue withBlock:^(FIRDataSnapshot * _Nonnull snapshot) {
NSDictionary *usersDict = snapshot.value;
NSLog(#"%#",usersDict);
[usersDict objectForKey:_user.uid];
//I've tried numerous solutions here to get the text fields to display the info from the database
mainly:
NSString *field;
field = _textFieldOne.text;
field = [userDict objectForKey #"Name"];
The code i'm attempting to translate from looks like this:
field(userDict?.objectForKey("Name") as? String)
}];
Any ideas?
I managed to get everything sorted as follows:
-(void)configure:(NSString *)field {
_textFieldOne.text = field;
}
and then within the code I was having the problem:
[[_rootRef child:#"users"] observeEventType:FIRDataEventTypeValue withBlock:^(FIRDataSnapshot * _Nonnull snapshot) {
NSDictionary *usersDict = snapshot.value;
NSLog(#"%#",usersDict);
[usersDict objectForKey:_user.uid];
[self configure:[userDict objectForKey:#"Name"]];
}];
Thanks for the help.
Hey Joshua I have implemented the firebase and successfully retrieve the data from the firebase but the problem is i have implemented that in swift... here is my actual code if this helps you......
**rootRef.queryOrderedByChild("search what you want like specific name etc etc").observeEventType(.ChildAdded, withBlock: { snapshot in
if snapshot.value is NSNull {
print("the chat model is null")
SVProgressHUD.dismiss()
SVProgressHUD.showErrorWithStatus("No messages")
}
else {
print(snapshot) }**
Or if you want to fetch the whole database JSON here is the query
**rootref.observeEventType(.ChildAdded) { (snapshot: FDataSnapshot!) in
// 3
let id = snapshot.value["senderId"] as! String
let text = snapshot.value["text"] as! String
// 4
self.addMessage(id, text: text)
// 5
self.finishReceivingMessage()
}**
Here is a nice tutorial on this
https://www.raywenderlich.com/122148/firebase-tutorial-real-time-chat
If you want this to convert in objective-c then of course I will help you
Related
I am using the following code to check for new contents in Firebase / Database.
It is basically working. But when the contents is empty the code crashes.
What is the proper way to handle the case where postDict is coming back empty?
Is there some error code that we can be checked.
I have tried to check the value of postDict.count, but with no result.
FIRDatabaseHandle resultHandle =
[dbRef observeEventType:FIRDataEventTypeValue
withBlock:^(FIRDataSnapshot * _Nonnull snapshot) {
NSDictionary *postDict = snapshot.value;
NSManagedObject *artWorkRcd;
for (NSString* artKey in postDict) {
// Some useful code.
.......
}
}];
FIRDataSnapshot has a method called exists that returns YES if there is actually data in the snapshot. You should check this before using snapshot.value.
This question already has an answer here:
Querying for existing nodes in Firebase is returning null
(1 answer)
Closed 6 years ago.
I am trying to understand how i can do a search in my Firebase database to check if a record exists and if so to grab details under that specific branch.
Currently i can accomplish what i need to by grabbing a specific record and placing it into a textfield and going from there, however i need to do a check on multiple records in the database till a specific record is found and from there load all the details under that branch.
Heres what i am doing currently;
Firebase *ref = [[Firebase alloc] initWithUrl: #"https://sizzling-inferno-255.firebaseio.com/"];
//Refer to users entity
Firebase *usersRef = [ref childByAppendingPath: #"id/"];
// Read data and react to changes
[usersRef observeEventType:FEventTypeValue withBlock:^(FDataSnapshot *snapshot) {
NSLog(#"%# -> %#", snapshot.key, snapshot.value);
NSDictionary *dict=[NSDictionary dictionaryWithDictionary:snapshot.value];
NSString *stri=[NSString stringWithFormat:#"%#",dict];
_textview1.text = stri;
string1 = snapshot.key;
_label1.text = string1;
}];
Feel free to check for yourself using the URL, i only use this for testing anyway.
I found something close to what i need however it is not in Objective C.
I'm new in firebase, but I've been working too much on the new version.
Is Record the name of your key inside of sizzling-inferno-255? So if it is. In this new version you can retrieve some info by:
FIRDatabaseReference *usersRef = [[FIRDatabase database] reference];
[[[[usersRef child:#"results"] child:#"sizzleing-inferno-255"] child:#"record"] observeEventType:FIRDataEventTypeValue withBlock:^(FIRDataSnapshot * _Nonnull snapshot) {
NSString *record = snapshot.value;
if(record.length > 0) {
// Yes! there is a record.
}
}
Is that what you want? Let me know.
I cant seem to retrieve any information from my firebase database. I created a table with both author and title available.
This is the code i ran in my ios app, but the app just keeps crashing.
// Get a reference to our posts
Firebase *ref = [[Firebase alloc] initWithUrl: #"**********"];
[ref observeEventType:FEventTypeChildAdded withBlock:^(FDataSnapshot *snapshot) {
NSLog(#"%#", snapshot.value[#"author"]);
NSLog(#"%#", snapshot.value[#"title"]);
}];
}
I cant tell whats going wrong, any help with this i will be appreciated.
Thank you
change event type to
[ref observeEventType:FEventTypeValue withBlock:^(FDataSnapshot *snapshot) {
NSLog(#"%#", snapshot.value[#"author"]);
NSLog(#"%#", snapshot.value[#"title"]);
}];
You would generally not store data like that right under your root node - it would generally be a child node(s) stored under the root node, like this:
sizzling-inferno-255
book_node_0
author: test_author
title: test title
book_node_1
author: another author
title: another title title
Firebase *ref = [[Firebase alloc] initWithUrl: #"sizzling-inferno-255"];
[ref observeEventType:FEventTypeChildAdded withBlock:^(FDataSnapshot *snapshot) {
NSLog(#"%#", snapshot.value[#"author"]);
NSLog(#"%#", snapshot.value[#"title"]);
}];
will iterate over each book node and return a snapshot of that node. So the first time a snapshot is returned, it will be
book_node_0
author: test_author
title: test title
and the second time a snapshot is returned will be
book_node_1
author: another author
title: another title title
the book_node keys are generated with childByAutoId.
ChildAdded reads in each child node one at a time as a snapshot.
Value reads in everything in the node; all child nodes, those children etc and can be a large amount of data. If the ref node contains children, like in this answer, all of the nodes are returned and they need to be iterated over to get the child data, so within the observe block...
for child in snapshot.children {
NSLog(#"%#", child.value[#"author"]);
}
Edit - and to specifically answer the OP question, here's how you do it with the Firebase structure in the question:
self.myRootRef = [[Firebase alloc] initWithUrl:#"https://**********"];
[ref observeEventType:FEventTypeChildAdded withBlock:^(FDataSnapshot *snapshot) {
NSString *key = snapshot.key;
NSString *value = snapshot.value;
if ( [key isEqualToString:#"author"] ) {
NSLog(#"author = %#", value);
} else if ([snapshot.key isEqualToString:#"title"] ) {
NSLog(#"title = %#", value);
}
}];
I've read that it's important to keep data flatter for Firebase and to also only nest data that you intend to call. I've done those things, but Firebase is still too slow at retrieving data. Here's an example:
My data looks like this:
--English
----Ari : 4
----Philip : 2
----John : 6
And my code looks like this:
[super viewDidLoad];
[[DataSource sharedInstance].selectedLanguageMutableArray removeAllObjects];
//Retrieving Data From Firebase
NSString* selectedLanguagePath = [NSString stringWithFormat:#"languages/%#", [DataSource sharedInstance].languageSelected];
Firebase *languagesRef = [[DataSource sharedInstance].ref childByAppendingPath:selectedLanguagePath];
[[languagesRef queryOrderedByValue] observeEventType:FEventTypeChildAdded withBlock:^(FDataSnapshot *snapshot) {
[self.distanceMutableArray addObject:snapshot.key];
NSLog(#"%#", snapshot.key);
NSLog(#"%#", snapshot.value);
NSLog(#"%#", self.distanceMutableArray);
}];
//Selected Languages Mutable Array
[[DataSource sharedInstance].selectedLanguageMutableArray removeAllObjects];
for (NSInteger i = 0; i < self.distanceMutableArray.count; i++) {
UserCustomizationData *item = [[UserCustomizationData alloc] init];
NSString* selectedUser = self.distanceMutableArray[i];
Firebase* selectedUserRef = [[DataSource sharedInstance].usersRef childByAppendingPath:selectedUser];
if (selectedUser.length > 0) {
Firebase* profilePicRef = [selectedUserRef childByAppendingPath:#"profilePicture"];
[profilePicRef observeEventType:FEventTypeChildAdded withBlock:^(FDataSnapshot *snapshot) {
NSString* profPicString = snapshot.value;
NSData *dataFromBase64=[NSData base64DataFromString:profPicString];
UIImage *profPicImage = [[UIImage alloc]initWithData:dataFromBase64];
item.profilePicture = profPicImage;
}];
[[DataSource sharedInstance].selectedLanguageMutableArray addObject:item];
}
}
However, the for loop runs before the self.distanceMutableArray can populate. This throws everything off because the for loop relies on the self.distanceMutableArray being populated.
Is there a way to retrieve data such that the code will run fluidly and in the order that it is written?
The issue here is that Firebase works via asynchronous calls; your code will not work consistently because the code below the Firebase block may be called before the block completes.
You will need to start coding asynchronously and only perform actions on snapshot data after you know for sure it has been populated (inside the block)
[[languagesRef queryOrderedByValue] observeEventType:FEventTypeChildAdded withBlock:^(FDataSnapshot *snapshot) {
//at this point, firebase has loaded the snapshot
// so its available to work with
[self.distanceMutableArray addObject:snapshot.key];
for (NSInteger i = 0; i < self.distanceMutableArray.count; i++) {
//do some stuff with the items in snapshot
}
}];
//don't work with anything that was from the snapshot as it may have not been filled yet
However there's an issue as the code is using childAdded, so that will iterate over each item in the firebase node, so that code won't work either as it won't load the array correctly (yes we can fix that by populating the array during each loop).
The additional challenge here is that you need to retrieve data from Firebase based on the result of your first snapshot. Again, same situation exists; only perform actions on that retrieved data after you know for sure it has been retrieved.
One solution is to load in the entire dataset at one time and iterate over it (by value instead of added). If your data sets are smaller that works. However, for big datasets that can be too much.
[[languagesRef queryOrderedByValue] observeEventType:FEventTypeValue withBlock:^(FDataSnapshot *snapshot) {
//at this point, firebase has loaded the snapshot
// so its available to work with and loaded with
//everything in the node
for ( FDataSnapshot *child in snapshot.children) {
NSDictionary *dict = child.value;
NSString *uid = child.key;
[self.distanceMutableArray addObject:uid];
}
// now the array is loaded do something with it
}];
Another option is to change how your data is stored in firebase so you can retrieve data together so you dont have to make multiple observe calls.
I am attempting to retrieve a PFUser which is inside a NSDictionary however I am not able to retrieve any data when I run my code. The PFUser in the provided dictionary is the User key. Here is my output:
// My dictionary
{
hours = "10 Hours";
location = j;
notes = h;
title = j;
user = "<PFUser: 0x7fea4d578d90, objectId: h1WOITDkrF, localId: (null)> {\n email = \"XXXXX#yahoo.com\";\n fullName = Pradyumn;\n username = Prnk281;\n }";
}
// Should be displaying the PFUser objectId displays null
2015-12-03 22:11:24.774 XXXXX[16176:816409] User ID: (null)
Here is my code as attempt to retrieve the objectId from within the PFUser,
-(void)savePressed:(UIBarButtonItem * __unused)button
{
NSArray * validationErrors = [self formValidationErrors];
if (validationErrors.count > 0){
[self showFormValidationError:[validationErrors firstObject]];
return;
}
NSLog(#"FormValues: %#",self.formValues);
PFUser *selectedUser = [self.formValues objectForKey:#"user"];
NSLog(#"User ID: %#", [selectedUser objectForKey:#"objectId"]);
[self.tableView endEditing:YES];
}
When you make a query to get this data just add one line in the query.
[query includeKey:#"YOUR COLUMN NAME"];
You will get all the details of user in your current dictionary try this out.
I managed to solve my answer by following the two given comments.
First I checked to see if my selectedUser was a available value, which it was:
NSLog(#"Selected user : %#",selectedUser);
Then I did what #paulw11 said and used selectedUser.objectId