phucnm

func getPost() -> Observable<Post> {
    let postRef = Database.database().reference()
        .child("posts")
    return postRef.rx_observeEvent(event: .childAdded)
        .map { Post(snapshot: $0) }
        .unwrap()
}

getPost()
//It will emit an Error Event in case timed out 

phucnm

class Post: Mappable {
    var postId: String?
    var title: String?
    var content: String?
    var author: String?
    var likes: [String]?
    
    func mapping(map: Map) {
        postId <- map[Post.firebaseIdKey]
        title <- map["title"]

phucnm

class DictionaryKeyTransform: TransformType {
    typealias Object = [String]
    typealias JSON = [String: Bool]
    
    func transformFromJSON(_ value: Any?) -> [String]? {
        guard let v = value as? JSON else { return [String]() }
        return Array(v.keys)
    }
    
    func transformToJSON(_ value: [String]?) -> [String : Bool]? {

phucnm

func getPosts() -> Observable<[Post]> {
    let postRef = Database.database().reference()
        .child("posts")
    return postRef.rx_observeSingleEvent(of: .value)
        .map { Mapper<Post>().mapArray(snapshot: $0) }
}
    
getPosts().subscribe(onNext: { posts in
    //show the data or do whatever you want
}, onError: { error in

phucnm

extension DatabaseQuery {
    
    func rx_observeSingleEvent(of event: DataEventType) -> Observable<DataSnapshot> {
        return Observable.create({ (observer) -> Disposable in
            self.observeSingleEvent(of: event, with: { (snapshot) in
                observer.onNext(snapshot)
                observer.onCompleted()
            }, withCancel: { (error) in
                observer.onError(error)
            })

phucnm

extension Mapper {
    func mapArray(snapshot: DataSnapshot) -> [N] {
        return snapshot.children.map { (child) -> N? in
            if let childSnap = child as? DataSnapshot {
                return N(snapshot: childSnap)
            }
            return nil
        //flatMap here is a trick
        //to filter out `nil` values
        }.flatMap { $0 }

phucnm

func getPost(postId: String, completion:@escaping ((Post?) -> Void)) {
    let postRef = Database.database()
        .reference().child("posts").child("postId")
    postRef.observeSingleEvent(of: .value, with: { (snapshot) in
        completion(Post(snapshot: snapshot))
    })
}

phucnm

extension BaseMappable {
    static var firebaseIdKey : String {
        get {
            return "FirebaseIdKey"
        }
    }
    init?(snapshot: DataSnapshot) {
        guard var json = snapshot.value as? [String: Any] else {
            return nil
        }

phucnm

class Post: Mappable {
    var postId: String?
    var title: String?
    var content: String?
    var author: String?
    
    func mapping(map: Map) {
        postId <- map["postId"]
        title <- map["title"]
        content <- map["content"]

phucnm

//Implement this delegate function
- (NSIndexPath *)tableView:(UITableView *)tableView willDeselectRowAtIndexPath:(NSIndexPath *)indexPath {
    if (<#condition#>) {
        return nil;
    }
    return indexPath;
}

//To disable selection a table view cell
//Implement tableView:willSelectRowAtIndexPath: