Fetch events from EKEventStore and show in tableView in Swift iOS8

Question

I'm trying to create a small application that will fetch all events and will show them in a tableView. My specific questions are: - Is my `fetchEvents()` method is implemented correctly? - Where should I call the `fetchEvent()` method in order to show the list when the app opens (is it in `viewDidLoad`?) and to refresh it after the addition/edit of a new event? Thanks! This is my code for the `MasterViewController.swift` file: ``` import UIKit import EventKitUI class MasterViewController: UITableViewController , EKEventEditViewDelegate{ var objects = NSMutableArray() let eventStore = EKEventStore() override func awakeFromNib() { super.awakeFromNib() } override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. self.navigationItem.leftBarButtonItem = self.editButtonItem() let addButton = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "insertNewObject:") self.navigationItem.rightBarButtonItem = addButton //…

Accepted Answer

First off, You should be doing the rest of the work in your `fetchEvents` function inside the callback for `eventStore.requestAccessToEntityType`:

```
func fetchEvents() -> NSMutableArray {
    eventStore.requestAccessToEntityType(EKEntityType()) completion: {
        granted, error in
        ... the rest of the code ...
    })
}
```

of course now that it's async, you'll need to return the data in a callback instead of returning it:

```
func fetchEvents(completed: (NSMutableArray) -> ()) {
    eventStore.requestAccessToEntityType(EKEntityType()) completion: {
        granted, error in
        let endDate = NSDate(timeIntervalSinceNow: 604800*10);   //This is 10 weeks in seconds
        let predicate = self.eventStore.predicateForEventsWithStartDate(NSDate(), endDate: NSDate(), calendars: nil)
        let events = NSMutableArray(array: self.eventStore.eventsMatchingPredicate(predicate))
        completed(events)
    })
}
```

But now you have another problem... you're using self in the closure, thereby capturing a reference, which can lead to a "reference cycle". In this particular case, I'm pretty sure that won't happen because `requestAccessToEntityType()` won't keep a reference to your closure (I'm pretty sure), but it's a good idea to use `[weak self]` whenever you you use `self` inside a callback function:

once you've done that, self is an optional though, so you need to make sure it's not nil…

```
func fetchEvents(completed: (NSMutableArray) -> ()) {
    eventStore.requestAccessToEntityType(EKEntityType()) completion: { [weak self]
        granted, error in
        if let strongSelf = self {
            let endDate = NSDate(timeIntervalSinceNow: 604800*10);   //This is 10 weeks in seconds
            let predicate = strongSelf.eventStore.predicateForEventsWithStartDate(NSDate(), endDate: NSDate(), calendars: nil)
            let events = NSMutableArray(array: strongSelf.eventStore.eventsMatchingPredicate(predicate))
            completed(events)
        }
    })
}
```

but looking a little closer, we never use `self` just `self.eventStore`, so we can capture a weak reference to that directly instead:

```
func fetchEvents(completed: (NSMutableArray) -> ()) {
    eventStore.requestAccessToEntityType(EKEntityType()) completion: { [weak weakEventStore = self.eventStore]
        granted, error in
        if let eventStore = weakEventStore {
            let endDate = NSDate(timeIntervalSinceNow: 604800*10);   //This is 10 weeks in seconds
            let predicate = eventStore.predicateForEventsWithStartDate(NSDate(), endDate: NSDate(), calendars: nil)
            let events = NSMutableArray(array: eventStore.eventsMatchingPredicate(predicate))
            completed(events)
        }
    })
}
```

finally, you really ought to check for errors instead of ignoring them, (`granted` could be false, meaning the user didn't give you access, or there could have been an error (so you need to check if `error` is nil (`if error { /* handle failure */ }`)

PS - I have working code which uses event kit on github which you may find useful.

Fetch events from EKEventStore and show in tableView in Swift iOS8

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