Contents.swift

//: [Previous](@previous)

//: For this page, make sure your build target is set to ParseSwift (iOS) and targeting
//: an iPhone, iPod, or iPad. Also be sure your `Playground Settings`
//: in the `File Inspector` is `Platform = iOS`. This is because
//: SwiftUI in macOS Playgrounds doesn't seem to build correctly
//: Be sure to switch your target and `Playground Settings` back to
//: macOS after leaving this page.

import PlaygroundSupport
import Foundation
import ParseSwift
import SwiftUI
PlaygroundPage.current.needsIndefiniteExecution = true

initializeParse()

//: Create your own value typed ParseObject.
struct GameScore: ParseObject {
    //: These are required for any Object.
    var objectId: String?
    var createdAt: Date?
    var updatedAt: Date?
    var ACL: ParseACL?

    //: Your own properties.
    var score: Int = 0
    var location: ParseGeoPoint?
    var name: String?

    //: Custom initializer.
    init(name: String, score: Int) {
        self.name = name
        self.score = score
    }
}

//: Be sure you have LiveQuery enabled on your server.

//: Create a query just as you normally would.
var query = GameScore.query("score" > 9)

//: To use subscriptions inside of SwiftUI
struct ContentView: View {

    //: A LiveQuery subscription can be used as a view model in SwiftUI
    @ObservedObject var subscription = query.subscribe!

    var body: some View {
        VStack {

            if subscription.subscribed != nil {
                Text("Subscribed to query!")
            } else if subscription.unsubscribed != nil {
                Text("Unsubscribed from query!")
            } else if let event = subscription.event {

                //: This is how you register to receive notificaitons of events related to your LiveQuery.
                switch event.event {

                case .entered(let object):
                    Text("Entered with score: \(object.score)")
                case .left(let object):
                    Text("Left with score: \(object.score)")
                case .created(let object):
                    Text("Created with score: \(object.score)")
                case .updated(let object):
                    Text("Updated with score: \(object.score)")
                case .deleted(let object):
                    Text("Deleted with score: \(object.score)")
                }
            } else {
                Text("Not subscribed to a query")
            }

            Spacer()

            Text("Update GameScore in Parse Dashboard to see changes here")

            Button(action: {
                try? query.unsubscribe()
            }, label: {
                Text("Unsubscribe")
                    .font(.headline)
                    .background(Color.red)
                    .foregroundColor(.white)
                    .padding()
                    .cornerRadius(20.0)
                    .frame(width: 300, height: 50)
            })
        }
    }
}

PlaygroundPage.current.setLiveView(ContentView())

//: This is how you subscribe to your created query using callbacks.
let subscription = query.subscribeCallback!

//: This is how you receive notifications about the success
//: of your subscription.
subscription.handleSubscribe { subscribedQuery, isNew in

    //: You can check this subscription is for this query
    if isNew {
        print("Successfully subscribed to new query \(subscribedQuery)")
    } else {
        print("Successfully updated subscription to new query \(subscribedQuery)")
    }
}

//: This is how you register to receive notificaitons of events related to your LiveQuery.
subscription.handleEvent { _, event in
    switch event {

    case .entered(let object):
        print("Entered: \(object)")
    case .left(let object):
        print("Left: \(object)")
    case .created(let object):
        print("Created: \(object)")
    case .updated(let object):
        print("Updated: \(object)")
    case .deleted(let object):
        print("Deleted: \(object)")
    }
}

//: Now go to your dashboard, go to the GameScore table and add, update or remove rows.
//: You should receive notifications for each.

//: This is how you register to receive notificaitons about being unsubscribed.
subscription.handleUnsubscribe { query in
    print("Unsubscribed from \(query)")
}

//: To unsubscribe from your query.
do {
    try query.unsubscribe()
} catch {
    print(error)
}

//: Create a new query.
var query2 = GameScore.query("score" > 50)

//: Select the fields you are interested in receiving.
query2.fields("score")

//: Subscribe to your new query.
let subscription2 = query2.subscribeCallback!

//: As before, setup your subscription and event handlers.
subscription2.handleSubscribe { subscribedQuery, isNew in

    //: You can check this subscription is for this query.
    if isNew {
        print("Successfully subscribed to new query \(subscribedQuery)")
    } else {
        print("Successfully updated subscription to new query \(subscribedQuery)")
    }
}

subscription2.handleEvent { _, event in
    switch event {

    case .entered(let object):
        print("Entered: \(object)")
    case .left(let object):
        print("Left: \(object)")
    case .created(let object):
        print("Created: \(object)")
    case .updated(let object):
        print("Updated: \(object)")
    case .deleted(let object):
        print("Deleted: \(object)")
    }
}

//: Now go to your dashboard, go to the GameScore table and add, update or remove rows.
//: You should receive notifications for each, but only with your fields information.

//: This is how you register to receive notificaitons about being unsubscribed.
subscription2.handleUnsubscribe { query in
    print("Unsubscribed from \(query)")
}

//: To unsubscribe from your query.
do {
    try query2.unsubscribe()
} catch {
    print(error)
}

PlaygroundPage.current.finishExecution()
//: [Next](@next)