CODEWITHSUNDEEP
iosswiftalamofire
Sayanee
Sayanee

Reputation: 5167

reload view / data after json request is completed in iOS Swift 2.1

I have a SectionsData.swift file where I get some data from a get http request:

import Foundation
import Alamofire

class SectionsData {
    func getSectionsFromData() -> [Section] {
        var sectionsArray = [Section]()

        let animals = Section(title: "Animals", objects:  ["Cats", "Dogs", "Lions", "Birds"], place: "Jungle")
        let vehicles = Section(title: "Vehicles", objects: ["Cars", "Bicycle"], place: "Road")
        let movies = Section(title: "Movies", objects: ["Sound", "Music"], place: "Cinema")

        sectionsArray.append(animals)
        sectionsArray.append(vehicles)
        sectionsArray.append(movies)

        Alamofire.request(.GET, "https://example.com")
            .responseJSON { response in
                if let JSON = response.result.value {
                    var openEvents = Section(title: "Events", objects: [], place: "Rooms")
                    for index in 0...9 {
                        let eventName = JSON["events"]!![index]["name"]! as! String
                        openEvents.items.append(eventName)
                    }

                    sectionsArray.append(openEvents)

                }
        }

        return sectionsArray
    }
}

And in the ViewController.swift file, I'm trying to reload the view after the JSON request is complete:

import UIKit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet weak var tableView: UITableView!

    var sections: [Section] = SectionsData().getSectionsFromData()

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return sections.count
    }

    func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return sections[section].heading
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return sections[section].items.count 
    }
    ...

Currently, I only see the static data with table view sections for "Animals", "Vehicles" and "Movies" and no "Events" section.

I believe I will need to reload the view somewhere. How can I do so?

Upvotes: 1

Views: 1478

Answers (1)

Laffen
Laffen

Reputation: 2771

First of all, inside your getSectionsFromData() you're calling an asynchronously call to Alamofire.request() which will not be executed in due time for the sectionsArray to have the returned data. You're in fact returning the static array from getSectionsFromData.

To fix this you could use a callback in the getSectionsFromData()

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate     {    

    var sections: [Section] = []

    override func viewDidLoad() {
        super.viewDidLoad()

        SecionsData().getSectionsFromData({
            sections in

            self.sections = sections

            self.tableView.reloadData()
        })
    }
}

class SectionsData {

    func getSectionsFromData(callback: (sections: [Section]) -> ()) {

        var sectionsArray = [Section]()

        let animals = Section(title: "Animals", objects:  ["Cats", "Dogs", "Lions", "Birds"], place: "Jungle")
        let vehicles = Section(title: "Vehicles", objects: ["Cars", "Bicycle"], place: "Road")
        let movies = Section(title: "Movies", objects: ["Sound", "Music"], place: "Cinema")

        sectionsArray.append(animals)
        sectionsArray.append(vehicles)
        sectionsArray.append(movies)


        Alamofire.request(.Get, "https://example.com")
            .responseJSON { response in

            if let JSON = response.result.value {
                var openEvents = Section(title: "Events", objects: [], place: "Rooms")
                for index in 0...9 {
                    let eventName = JSON["events"]!![index]["name"]! as! String
                    openEvents.items.append(eventName)
                }

                sectionsArray.append(openEvents)
            }

            // This will pass the sections with or without any fetched data into the callback
            callback(sections: sectionsArray)
        }
    }
}

Swift Closures

Upvotes: 4

Related Questions