Filter Array of [AnyObject] in Swift

Onichan picture Onichan · Dec 30, 2014 · Viewed 60.6k times · Source

I have an array of AnyObject objects in Swift. Each object has attributes of a restaurant, such as name, type, loc, etc. How can I filter the array if I want to keep all objects in the array that contain type: "Sushi".

Sample array of [AnyObject] with 2 objects. The filter should keep the first object (type: sushi):

[<Restaurant: 0x7ff302c8a4e0, objectId: LA74J92QDA, localId: (null)> {
    City = "New York";
    Country = "United States";
    Name = Sumo Japan;
    Type = Sushi, Japanese, Asian;
}, <Restaurant: 0x7ff302daa790, objectId: 0aKFrpKN46, localId: (null)> {
    City = "New York";
    Country = "United States";
    Name = Little Italy;
    Type = Italian, Pizza;
}]

Current Code (but I'm not sure if the filter can search through an array of [AnyObject]) :

var query = PFQuery(className:"Restaurant")
query.whereKey("RestaurantLoc", nearGeoPoint:userGeoPoint, withinMiles:50)
query.limit = 2
query.findObjectsInBackgroundWithBlock {
    (objects: [AnyObject]!, error: NSError!) -> Void in
    if objects != nil {
        println("list of objects of nearby")
        println(objects)
        let searchString = "Sushi"
        let predicate = NSPredicate(format: "Type CONTAINS[cd] %@", searchString);

        //Line below gives error: '[AnyObject]' does not have a member named 'filteredArrayUsingPredicate'
        //let filteredArray = objects.filteredArrayUsingPredicate(predicate!)

Answer

Rob picture Rob · Dec 30, 2014

Your array, objects, is an array of PFObject objects. Thus, to filter the array, you might do something like:

let filteredArray = objects.filter() {
    if let type = ($0 as PFObject)["Type"] as String {
        return type.rangeOfString("Sushi") != nil
    } else {
        return false
    }
}

My original answer, based upon an assumption that we were dealing with custom Restaurant objects, is below:


You can use the filter method.

Let's assume Restaurant was defined as follows:

class Restaurant {
    var city: String
    var name: String
    var country: String
    var type: [String]!

    init (city: String, name: String, country: String, type: [String]!) {
        ...
    }
}

So, assuming that type is an array of strings, you'd do something like:

let filteredArray = objects.filter() {contains(($0 as Restaurant).type, "Sushi")}

If your array of types could be nil, you'd do a conditional unwrapping of it:

let filteredArray = objects.filter() {
    if let type = ($0 as Restaurant).type as [String]! {
        return contains(type, "Sushi")
    } else {
        return false
    }
}

The particulars will vary a little depending upon your declaration of Restaurant, which you haven't shared with us, but hopefully this illustrates the idea.