How to load JSON Data into FSCalendar Swift 5 - ios

Question

I am trying to load my JSON Data into FSCalendar.
I understand from the documentation that when you use an array that can be show in the calendar with the dots. I am wanting to do that same thing but instead to have the dots appear from my dates listed in my JSON file. I have loaded the JSON file into my bundle as well as made a function to load the JSON data and I have created a structure.
My problem comes in when I am trying to use an array from the structure and then load that array into the "func calendar(_ calendar: FSCalendar, numberOfEventsFor date: Date) -> Int {" function. I have been working on this for a while and could use some help. Thanks
JSON Data: - I titled the JSON file data.json
[
{
"event": "Christmas",
"date": [
"2021-01-02",
"2021-01-03",
"2021-01-04"
]
}
]
View Controller:
import UIKit
import FSCalendar
class ViewController: UIViewController, FSCalendarDelegate, FSCalendarDataSource, FSCalendarDelegateAppearance {
//MARK: - calendar variables
#IBOutlet var calendar: FSCalendar!
#IBOutlet weak var dateLabel: UILabel!
fileprivate let gregorian: Calendar = Calendar(identifier: .gregorian)
fileprivate lazy var dateFormatter1: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy/MM/dd"
return formatter
}()
fileprivate lazy var dateFormatter2: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd"
return formatter
}()
// These are just test data to see the dots on the calendar
var datesWithEvents = ["2021-01-15","2021-01-16","2021-01-17","2021-01-18"]
var datesWithMultipleEvents = ["2021-01-20","2021-01-21","2021-01-22","2021-01-23"]
//MARK: - JSON variable
// var result: Results?
let data = DataLoader().eventData
//MARK: - viewdidload
override func viewDidLoad() {
super.viewDidLoad()
// parseJSON()
let data = DataLoader().eventData
print(data)
calendar.delegate = self
calendar.dataSource = self
}
deinit {
print("\(#function)")
}
//MARK: - calendar functions
func calendar(_ calendar: FSCalendar, didSelect date: Date, at monthPosition: FSCalendarMonthPosition) {
let formatter = DateFormatter()
formatter.dateFormat = "EEEE MM-dd-YYYY"
let string = formatter.string(from: date)
print("\(string)")
}
func calendar(_ calendar: FSCalendar, appearance: FSCalendarAppearance, eventDefaultColorsFor date: Date) -> [UIColor]? {
let key = self.dateFormatter2.string(from: date)
// this is the test with the hard coded arrays, I think i need to
implement the JSON here but am not sure how
if self.datesWithMultipleEvents.contains(key) {
return [UIColor.magenta, appearance.eventDefaultColor, UIColor.red]
}
return nil
}
func calendar(_ calendar: FSCalendar, numberOfEventsFor date: Date) -> Int {
let dateString = self.dateFormatter2.string(from: date)
if self.datesWithEvents.contains(dateString) {
return 1
}
if self.datesWithMultipleEvents.contains(dateString) {
return 3
}
return 0
}
Data Model:
struct EventsData: Codable {
var event: String
var date: [String]
}
JSON loader:
import Foundation
public class DataLoader {
#Published var eventData = [EventsData]()
init() {
load()
}
func load() {
if let fileLocation = Bundle.main.url(forResource: "data", withExtension: "json") {
//do catch incase of error
do {
let data = try Data(contentsOf: fileLocation)
let jsonDecoder = JSONDecoder()
let dataFromJson = try jsonDecoder.decode([EventsData].self, from: data)
self.eventData = dataFromJson
} catch {
print(error)
}
}
}
}
EDIT:
func calendar(_ calendar: FSCalendar, numberOfEventsFor date: Date) -> Int {
let dateString = self.dateFormatter2.string(from: date)
if self.eventData.contains(where: //<#T##(EventsData) throws -> Bool#>) //How to get this to do the contains like in the next if statement
if self.datesWithEvents.contains(dateString) {
return 1
}
if self.datesWithMultipleEvents.contains(dateString) {
return 3
}
return 0
}

Answer 1

Check if you have this in your code:
// FSCalendarDataSource
func calendar(calendar: FSCalendar!, hasEventForDate date: NSDate!) -> Bool {
return shouldShowEventDot
}

Answer 2

Just convert your string date into Date with DateFormatter and then just go through your array and check if the date (from the calendar function) matches any of your dates in the event.

Answer 3

You have a number of problems.
First, you are trying to use SwiftUI constructs (#Published) in a Swift app. That won't work.
Second, you have your dates coming in as an array of strings. I suggest setting up your Codable protocol conformance using a custom Date decoding stategy.
This link shows how to set up your JSONDecoder to use a custom date decoding strategy that takes a custom DateFormatter.
Next, you need some way to update your UI when new data is read from your JSON input. SwiftUI has built-in mechanisms for automatically responding to state changes, but you're not using SwiftUI, so those don't apply.
You have a DataLoader class that loads JSON data. It currently reads hard-coded JSON from a file, synchronously. I assume that you want to load the data from the internet, which would be async. Thus your approach won't work.
I suggest you set up your DataLoader class to either have a delegate that it notifies when it has completed loading new data, or set it up to take requests with a completion handler.
If you don't know how to do either of those things then you need to stop and learn some fundamentals. Read up on Swift async networking, completion handlers, and the delegate design pattern before you continue.