I am making a simple like button. When a person presses the like button, the code is checking if the user already pressed like before. If not, it sends data to Firebase saying the user is liking this post, and it is then changing the textColor of the button to blue.
My problem is, when the user closes the app and opens it again, none of the buttons are blue. Even though the user liked several posts. I need some kind of code that can check if the user already liked the post and change the textColor to blue when the UITableViewController is loading, I guess?
I tried to do that in my code, but it gets an error. So can anyone tell me how to go from here? My like button code:
func checkClickOnLikeButton() {
let dataPathen = self.pathDB
// print(dataPathen)
if let user = FIRAuth.auth()?.currentUser {
let userId = user.uid
FIRDatabase.database().reference().child("feed-items").child(dataPathen).child("likesForPost").observeSingleEventOfType(.Value, withBlock: { (snapshot) in
// Get user value
self.gottenUserId = snapshot.value![userId] as? Bool
// print(self.gottenUserId)
if self.gottenUserId == true {
print("Der er trykket high five før")
} else {
print("Der er IKKE trykket like før")
let quoteString = [userId: true]
FIRDatabase.database().reference().child("feed-items").child(dataPathen).child("likesForPost").updateChildValues(quoteString)
let blueButtonColor = UIColor(red: 0/255, green: 122/255, blue: 255/255, alpha: 1.0)
self.highFiveButton.setTitleColor(blueButtonColor, forState: UIControlState.Normal)
}
// ...
}) { (error) in
print(error.localizedDescription)
}
}
}
Id create a struct that fits your data. I would then keep the data you pull from the database locally in an array.
While building the table i.e cellForRowAtIndexPath, check indexPath.row against the value in your array to see if you've liked it.
If you have liked it, i.e arrayOfUsers[indexPath.row].contains("myUserID"), then adjust your button to show already liked, and assign a number to the counter. Else, Do nothing.
Also - It wouldn't hurt to keep the query updated rather than doing observeSingleEventOfType(...), The reason I say this is you can then tell the query to persist data so even if the user closes app. launches your app on an iPad, and then goes back to the phone, the iPhone will be updated thanks to firebase.
So, to summarize that last bit, I would recommend changing the query not to observer once, and have it call specific functions when a child is removed / added
Related
So my goal is to smoothly load the viewController with no split second bugs. I have a function that is used to determine what buttons to show when the view loads based off a field in a Firestore document. Here is the function:
func determinePurchasedStatusVerification() {
db.collection("student_users/\(user?.uid)/events_bought").whereField("event_name", isEqualTo: selectedEventName!).whereField("isEventPurchased", isEqualTo: true).getDocuments { (querySnapshot, error) in
if let error = error {
print("\(error)")
} else {
guard let querySnap = querySnapshot?.isEmpty else { return }
if querySnap == true {
self.purchaseTicketButton.isHidden = false
self.viewPurchaseButton.isHidden = true
self.cancelPurchaseButton.isHidden = true
} else {
self.purchaseTicketButton.isHidden = true
self.viewPurchaseButton.isHidden = false
self.cancelPurchaseButton.isHidden = false
}
}
}
}
I call this function in the viewWillAppear() of the vc but when I instantiate to that vc, this is the result...
The extra purchase ticket button shows up for a split second. Even though it's very quick, you can still see it and it's just not something a user would need to see. It's also the other way around when you click on a cell that's not purchased, the two bottom buttons show up for a split second. I just want to know how I can prevent this quick bug and be able to display a smooth segue with no delays in the button hiding. Thanks.
getDocuments is an asynchronous function, meaning it doesn't call its callback function immediately -- it calls it when it gets data back from the server. It may seem like a split second just because your internet connection is fast and the Firebase servers are definitely fast, but it's a non-zero time for sure. And, someone with a slower connection might experience much more of a delay.
Unless your callback is getting called twice with different results (which seems doubtful), the only solution here is to make sure that your initial state has all of the buttons hidden (and maybe a loading indicator) and then show the buttons that you want once you get the data back (as you are right now). My guess is, though, that you have an initial state where the buttons are visible, which causes the flicker.
I'm working on a project where I should save data locally with Core Data.
Here is my workflow :
To start, I ask the user to fill a form, let's say his firstname and lastname.
He clicks on the submit button, then data is saved on the device using Core Data
User is redirected to the "last filled form" view controller.
I have a bar button item that when clicked can show the latest filled form.
I should test if the array of filled forms is empty, then the button should be disabled.
Otherwise, the button should be enabled ...
I tried this piece of code, where I fetch data from the database and affected to an array but the button seams not working at all and it never gets disabled ...
class ViewController: UIViewController {
var userIdentity: UserIDentity = UserIDentity(context: PersistanceService.context)
var identityArray = [UserIDentity]()
override func viewDidLoad() {
super.viewDidLoad()
self.fetchIdentityHistoryArray()
}
func fetchIdentityHistoryArray(){
let fetchRequest: NSFetchRequest<UserIDentity> = UserIDentity.fetchRequest()
do {
let identityArray = try PersistanceService.context.fetch(fetchRequest)
if identityArray.isEmpty {
self.identityHistoryButton.isEnabled = false
}
else {
self.identityHistoryButton.isEnabled = true
}
}
catch {
print("Error fetching sworn statement history !")
}
}
}
So I have 2 questions :
What's wrong with my code ?
How can I manage that when the user clicks on the "back button" for the first form filled ever, the "history button" can refresh itself and turn from disabled to enabled button ?
Any help is much appreciated. Thank you
You are initialising a core data object directly in your code
var userIdentity: UserIDentity = UserIDentity(context: PersistanceService.context)
This new object will exist in Core Data and will be included everytime you execute the fetch request. You must understand that Core Data is not a database layer it is an object mapping layer so even if you haven't called save() yet the object exists in the Core Data context.
Either change the declaration to
var userIdentity: UserIDentity?
or remove it completely if it isn't used.
I was wondering how to create a favorite button in swift that when that button is pressed the object that is "favorited" becomes part of a tableview and stays that way. I hear that core data is a way to do this, but I am still struggling to have the button change when pressed.
When I was creating a button all I get is a button that only changes the first time it presses. An example is I have an empty star button, which means that it is not a favorite, and when i pressed it it changes to a filled heart, which means that it is favorited. When I press the button a second time, when it is currently a filled star, it doesn't change and still remains a filled star.
The other problem that I am having is sending the information from the object to a favorite tableview. I am not sure how to keep something in a tableview as long as the favorite button is switched to filled star.
What I am seeing a lot of is this topic but it is all about making a favorite button in table views. I am not looking for tableviews. An example of what I am trying to do is like a favorite book app. The app opens as a tableview full of books, and when a cell is pressed it opens a new view controller with that book's information, and at the top is a favorite button that is normally an empty star. If I like that book I would like to press that button and the empty star becomes a filled star button, indicating that I like it. The book's information is then sent to a new table view that holds all of the liked books i have done before. If I no longer like that book i would like to press the filled star button again and it is removed from the favorite tableview list.
I am some experience with mysql in regards to swift, and I know that someone people have made comments about using some kind of persistence to save the state of the button.
My biggest problem is that I don't even know where to start. Every attempt I make seems to end the same way, so i don't really have any source code for others to see. I have looked online and through github but the closest thing I could find was a cocoapod named DoButton, but it hasn't been updated in a long time and I am worried that it won't last with another swift update. If someone could lead me in the right path or know a good tutorial, I would greatly appreciate it. If there are any questions I can answer i will answer them to the best of my ability.
Another Update: I managed to get the button to work. It connects to core data and saves the state of the button even when it is quit. Now all that is left is creating a favorite tableView to store the favorites.
Here is the code:
class ViewController: UIViewController {
var buttonIsSelected = false
var favorites = [Favorite]()
#IBOutlet var onOffButton: UIButton!
let image1 = UIImage(named: "empty") as UIImage?
let image2 = UIImage(named: "filled") as UIImage?
override func viewDidLoad() {
super.viewDidLoad()
print("buttonIsSelected: \(buttonIsSelected)")
let fetchedRequest: NSFetchRequest<Favorite> = Favorite.fetchRequest()
do {
let favorite = try PersistenceService.context.fetch(fetchedRequest)
for fav in favorite {
resetAllRecord(entity: fav.favorite)
buttonIsSelected = fav.favorite
print("fav.favorite: \(fav.favorite)")
print("button: \(buttonIsSelected)")
if fav.favorite == true {
onOffButton.setImage(image2, for: .normal)
}
}
} catch {
}
}
//button Action
#IBAction func onOffButtonPressed(_ sender: Any) {
buttonIsSelected = !buttonIsSelected
if buttonIsSelected == true {
onOffButton.setImage(image2, for: .normal)
} else if buttonIsSelected == false {
onOffButton.setImage(image1, for: .normal)
}
saveBool(bool: buttonIsSelected)
}
//save to core data
func saveBool(bool: Bool) {
if bool == true {
print("favorite")
print("buttonIsSelected \(buttonIsSelected)")
let liked = Favorite(context: PersistenceService.context)
liked.favorite = bool
PersistenceService.saveContext()
favorites.append(liked)
} else if bool == false {
print("unfavorite")
print("buttonIsSelected \(buttonIsSelected)")
let liked = Favorite(context: PersistenceService.context)
liked.favorite = bool
PersistenceService.saveContext()
favorites.append(liked)
}
}
//clears core data so it doens't get full
func resetAllRecord(entity: Bool) {
let context = PersistenceService.persistentContainer.viewContext
let deleteFetch = NSFetchRequest<NSFetchRequestResult>(entityName: "Favorite")
let deleteRequest = NSBatchDeleteRequest(fetchRequest: deleteFetch)
do
{
try context.execute(deleteRequest)
try context.save()
}
catch
{
print ("There was an error")
}
}
}
In the object class create a bool parameter called isFavorite and default set it to false. When the favorite button is pressed the bool should change from false to true. When you have to access only the "favorite" objects, with a for loop iterate through your array of objects and through an if statement check if the isFavorite parameter is true. If it is, the element must be appended to a new object array maybe called favoriteObjects, and there you have all your favorite objects. The rest is pretty straightforward.
I've got a class where I handle my touches functions on buttons, and those buttons are also a Post class.
The logic I'm going for is "If the post.user is equal to the current firebaseuser, don't allow the user to move the button"
Here's what I tried:
In my "DragButtonsClass" I've got a notification being sent to my view controller on TouchesBegan.
In the view I've got
func touchesStarted(notif : NSNotification) {
if let dict = notif.userInfo! as? [NSObject: AnyObject] {
let tag = dict["tag"]!
let tagInt = Int(String((tag))) //this is probably super sloppy, don't know how else to change an AnyObject to an Int though.
let post = postArray[tagInt! - 1]
let postbutton = self.view.viewWithTag(tagInt!)
if post.user == currentUser {
postbutton?.userInteractionEnabled = false
print("Should be working")
} else {
print("Didn't work")
}
}
}
Basically I'm assigning tags to the buttons as they're created and those tags line up with my Posts array. I'm trying to check if the Post's user is the same as the current user by sending it over and then shut off user interaction.
I'm getting "Should be working" to print out but the button is still draggable.
This seems like a super sloppy and roundabout way to do this and most importantly it isn't working. I've read that turning off userInteraction is a way to stop touches from being recognized.
Any ideas?
Ended up just setting a bool "canBeDragged" in my button's class, and when the button is created the current user's ID is compared to the information being pulled from firebase and the bool is set. Then I just checked if the button could be dragged before my touchesMoved.
A quick overview of what I'm trying to make. I'm making an app to show my film reviews. I have a PFQueryTableviewController of which I use a custom cell. This table shows films which come from my Parse database. In each cell, there a 3 UIButtons, of which I want the user to use to vote for the film (happyVote, OkVote, sadVote). Over the top of each button is a UILabel that simply displays a count.
How I want it to work
When a user presses one of the buttons, the vote increases by 1.
When a user presses the same button again, the vote decreases by 1. Or,
If the user had pressed a different button, the vote decreases on the first button and increases on the button just pressed.
The user can only ever vote on one of the buttons.
The vote is shown by the UILabel showing the count, and by the button image changing.
See below for a visual:
This is what I've added in Parse:
So far, I've added the code to increase the vote count in Parse, in my TableViewController.swift:
#IBAction func upVoteButton(sender: AnyObject) {
let hitPoint = sender.convertPoint(CGPointZero, toView: self.tableView)
let hitIndex = self.tableView.indexPathForRowAtPoint(hitPoint)
let object = objectAtIndexPath(hitIndex)
object!.incrementKey("UpVoteCount")
object!.saveInBackground()
self.tableView.reloadData()
}
This kind of works, except, the user can keep increasing the count, and they can vote on all 3 buttons. And it doesn't change the Button Image when pressed.
In my cellForRowAtIndexPath method, I've put:
let downVote = object!.valueForKey("DownVoteCount") as! Int
cell.downVoteLabel.text = "\(downVote)"
let middleVote = object!.valueForKey("MiddleVoteCount") as! Int
cell.middleVoteLabel.text = "\(middleVote)"
let upVote = object!.valueForKey("UpVoteCount") as! Int
cell.upVoteLabel.text = "\(upVote)"
I have searched for a while for some examples of how to figure the rest out, but can't find anything, and I'm really struggling to figure the next steps out.
Any help will be greatly appreciated, and please let me know if you need/want to see anymore of my code. Thanks
In your upVoteButton() method, you can add the other two buttons and set them button.enabled = false inside an if statement like:
if downVoteButton.enabled == true {
downVoteButton.enabled = false
} else if downVoteButton.enabled == false {
downVoteButton.enabled = True
}
And do the same with the middleVoteButton in antoher if statement or the same, whatever floats your boat, also within the other button methods with the appropriate buttons. This helps disables the buttons when pressed and then enables it when it's pressed again.
And for the image changing you can follow this.