问题
I am trying to create a like button for my UITableViewCell. What I have managed to do so far is update the number of likes with +1 everytime the button is clicked. I, however, only want the user to be able to press the button once, and if it is clicked again by the same user, the user is unliking the post - just as the facebook like button.
If it is any help, I am signing in to my app via facebook.
My code:
@IBAction func likeTapped(sender: AnyObject) {
//print(pathDB)
FIRDatabase.database().reference().child("feed-items").child(pathDB).observeSingleEventOfType(.Value, withBlock: { (snapshot) in
// Get user value
let antalLikes = snapshot.value!["likesForPost"] as! Int
print(antalLikes)
let dataPathen = self.pathDB
print(dataPathen)
self.updateTotalNoOfPost{
print("Updated")
}
// ...
}) { (error) in
print(error.localizedDescription)
}
}
func updateTotalNoOfPost(completionBlock : (() -> Void)){
let prntRef = FIRDatabase.database().reference().child("feed-items").child(pathDB).child("likesForPost")
prntRef.runTransactionBlock({ (resul) -> FIRTransactionResult in
if let dealResul_Initial = resul.value as? Int{
resul.value = dealResul_Initial + 1
//Or HowSoEver you want to update your dealResul.
return FIRTransactionResult.successWithValue(resul)
}else{
return FIRTransactionResult.successWithValue(resul)
}
}, andCompletionBlock: {(error,completion,snap) in
print(error?.localizedDescription)
print(completion)
print(snap)
if !completion {
print("Couldn't Update the node")
}else{
completionBlock()
}
})
}
Here you have my structure in firebase:
Hope you guys can help me :)
回答1:
If your JSON is something like this:-
{
feed-items: {
feedItem1 :{
feedText : "This is feed1",
feedLikes : {uid1 : "true",
uid2 : "true"
}
},
feedItem2 :{
feedText : "This is feed2",
feedLikes : {uid13 : "true",
uid2 : "true"
}
},
feedItem3 :{
feedText : "This is feed4",
feedLikes : {uid4 : "true",
uid10 : "true"
}
},
}
}
Before retrieving you will have to check if the user had already liked this post, and set the state of the like button accordingly:-
For storing the retrieved dictionary use:-
struct feed {
var feedLikes : NSMutableDictionary!
var feedText : String!
var doILikeThisPost : Bool!
var feedNameI : String!
init(likes:NSMutableDictionary!, feed : String!, likeTisPost : Bool!, feedNM : String!){
self.doILikeThisPost = likeTisPost
self.feedLikes = likes
self.feedText = feed
self.feedNameI = feedNM
}
}
In your tableViewController:-
import UIKit
import Firebase
class customTableViewController : UIViewController, UITableViewDelegate ,UITableViewDataSource{
var feedD = [feed]()
@IBOutlet wear var customTableView : UITableView!
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
customTableView.delegate = self
customTableView.dataSource = self
retrieveTheData()
}
func retrieveTheData(){
FIRDatabase.database().reference().child("feed-items").observeSingleEventOfType(.Value, withBlock: {(allFeeds) in
if let feedDict = allFeeds.value as? [String: AnyObject]{
for each in feedDict{
if let feedLikesDict = each.1["feedLikes"] as? NSMutableDictionary{
if feedLikesDict[currentUerID] != nil{
let temp = feed.init(likes: feedLikesDict, feed: each.1["feedText"] as! String, likeTisPost: true, feedNM : each.0)
self.feedD.insert(temp, atIndex: 0)
self.customTableView.reloadData()
}else{
let temp = feed.init(likes: feedLikesDict, feed: each.1["feedText"] as! String, likeTisPost: false, feedNM : each.0)
self.feedD.insert(temp, atIndex: 0)
self.customTableView.reloadData()
}
}else{
let temp = feed.init(likes: nil, feed: each.1["feedText"] as! String, likeTisPost: false, feedNM : each.0)
self.feedD.insert(temp, atIndex: 0)
self.customTableView.reloadData()
}
}
}
})
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return feedD.count ?? 0
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = self.customTableView.dequeueReusableCellWithIdentifier("CELL") as! customCell
if feedD[indexPath.row].doILikeThisPost == true{
cell.feedLikeBtn.selected = true
cell.feedTextPost = feedD[indexPath.row].feedText
cell.feedName = feedD[indexPath.row].feedNameI
cell.parentTableViewController = self
cell.indexPathForRow = indexPath.row
}else{
cell.feedLikeBtn.selected = false
cell.feedTextPost = feedD[indexPath.row].feedText
cell.feedName = feedD[indexPath.row].feedNameI
cell.parentTableViewController = self
cell.indexPathForRow = indexPath.row
}
return cell
}
}
You customTableViewCell:-
class customCell : UITableViewCell{
@IBOutlet weak var feedLikeBtn : UIButton!
var feedTextPost = String()
var feedName = String()
var indexPathForRow : Int!
var parentTableViewController : customTableViewController!
@IBAction func likeBtn(sender:UIButton!){
if sender.selected == false{
FIRDatabase.database().reference().child("feed-items").child(feedName).child("feedLikes").updateChildValues([currentUserID : "true"])
self.parentTableViewController.feedD[self.indexPathForRow].feedLikes.setObject("true", forKey: currentUserID)
self.parentTableViewController.feedD[self.indexPathForRow].doILikeThisPost = true
self.parentTableViewController.customTableView.reloadData()
}else if sender.selected == true{
FIRDatabase.database().reference().child("feed-items").child(feedName).child("feedLikes").child(currentUserID).removeValue()
self.parentTableViewController.feedD[self.indexPathForRow].feedLikes.removeObjectForKey(currentUserID)
self.parentTableViewController.feedD[self.indexPathForRow].doILikeThisPost = false
self.parentTableViewController.customTableView.reloadData()
}
}
}
Also see :-https://stackoverflow.com/a/39458044/6297658
来源：https://stackoverflow.com/questions/39489362/like-button-in-firebase-swift