Filter array of objects on property with NSPredicate

Question

I have an array of Studios. Each studio, has a property called studioName.

I need my searchfield to filter the studios, based on the studioName, applied to the searchfield by the user.

Here's my current code:

var studios = [Studio]()
var filteredStudios = [Studio]()
var studiosToDisplay = [Studio]()

func updateSearchResultsForSearchController(searchController: UISearchController) {
    let searchText = searchController.searchBar.text

    print("SEARCH TEXT: \(searchText)")

    if searchText == nil || searchText!.isEmpty {
        studiosToDisplay = studios
        self.resultTableView.reloadData()
        NSNotificationCenter.defaultCenter().postNotificationName("showResultsBeforeSearchingNotification", object: nil) //Calls SearchVC
    } else {
        studiosToDisplay.removeAll()
        let searchPredicate = NSPredicate(format: "studioName CONTAINS[c] %@", searchText!)
        let array = (self.studios as NSArray).filteredArrayUsingPredicate(searchPredicate)
        studiosToDisplay = array as! [Studio]
        self.resultTableView.reloadData()
    }
}

It's just not working wight, right now.. It filters, but I end up with the same Studio left each time, no matter what I put in the searchfield.

I guess I need to make the predicate know, that it has to look at the single object in the array, each time. But I just can't figure out how. I tried to add "ANY" in the format, but that crashes my app.

You should tag your question properly as it seems that you are using Swift 2 (I recommend updating your Xcode to the latest Xcode available at the APP Store) — Leo Dabus
– Leo Dabus, Commented Apr 23, 2017 at 13:51
On a side note: checking for nil with searchText == nil, then force unwrapping (searchText!) is really bad practice — Alexander
– Alexander, Commented Apr 23, 2017 at 15:45

Alexander · Accepted Answer · 2017-05-25 19:03:19Z

9

This is unnecessarily complex. There's no need for NSPredicate here.

var studios = [Studio]()
var filteredStudios = [Studio]()
var studiosToDisplay = [Studio]()

func updateSearchResultsForSearchController(searchController: UISearchController) {
    let searchText = searchController.searchBar.text

    print("SEARCH TEXT: \(searchText)")

    if let searchText = searchText, !searchText.isEmpty {
        studiosToDisplay = studios.filter{ $0.studioName.contains(searchText) }
    }
    else {
        studiosToDisplay = studios
        NSNotificationCenter.defaultCenter().postNotificationName("showResultsBeforeSearchingNotification", object: nil) //Calls SearchVC
    }

    self.resultTableView.reloadData()
}

edited May 25, 2017 at 19:03

answered Apr 23, 2017 at 15:43

Alexander

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Comments

Nicolai Harbo · Accepted Answer · 2017-04-24 09:17:54Z

1

Thanks to @Alexander .. Here's the code I ended up using:

func updateSearchResultsForSearchController(searchController: UISearchController) {

    let searchText = searchController.searchBar.text

    if let searchText = searchText {
        if !searchText.isEmpty {
            self.studiosToDisplay = self.studios.filter { $0.studioName!.containsString(searchText) }
            for studio in self.studiosToDisplay {
                print("\(studio.studioName!)")
            }
        }
        else {
            self.studiosToDisplay = self.studios
            NSNotificationCenter.defaultCenter().postNotificationName("showResultsBeforeSearchingNotification", object: nil) // Calls SearchVC
        }
    }

    self.resultTableView.reloadData()

}

I figured out, that my former code, with the NSPredicate actually was functional - I was just presenting the wrong array in my tableview.. Oops.. But now it works, and I stick to the more simple code. Don't know why I didn't think of using the $0-function :) .. Anyway, thanks!

answered Apr 24, 2017 at 9:17

Nicolai Harbo

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1 Comment

Alexander Over a year ago

You can use a guard statement to bind searchText without that extra level of indentation

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