Filter Array of [AnyObject] in Swift - swift

Question

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 1

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.

Answer 2

Swift 3 Solution
Use the filter method on an array.
let restaurants: [Restaurants] = [...]
restaurants.filter({(restaurant) in
return Bool(restaurant.type == "sushi")
})
or return Bool(restaurant.type.contains("sushi")) if type is an array.

Answer 3

Ok, if the array objects contains only Restaurant(s) the following code does work.
Lets say Restaurant is something like this:
enum RestaurantType {
case Sushi, Japanese, Asian
}
class Restaurant {
var type = [RestaurantType]()
// more properties here...
}
First of all lets define an array of Restaurant(s).
var restaurants = objects as [Restaurant]
Then we can filter it:
var sushiRestaurants = restaurants.filter { (restaurant : Restaurant) -> Bool in
return contains(restaurant.type, .Sushi)
}
Update:
Now I am assuming objects is an array of PFObject(s)
Just ignore my previous code and try this:
var restaurants = objects as [PFObject]
var sushiRestaurants = restaurants.filter { (restaurant : PFObject) -> Bool in
return contains(restaurant["Type"], "Sushi")
}
Maybe it will crash again, the problem is that I don't know the type of Restaurant.Type. I'm trying. Maybe the next error message will provide more useful info.

Answer 4

Modification of Rob's answer as Swift 2.0, In swift 2.0 using Rob's code gives error as follows -
initializer for conditional binding must have optional type, not 'string'
However it can be solved by using guard statement instead of if-let as below -
let filteredArray = objects.filter() {
guard let type = ($0 as PFObject)["Type"] as String else {
return false
}
return type.rangeOfString("Sushi") != nil
}

Answer 5

I have a solution as given below.
func filterByCuisineType(list: [Restaurant]) -> [Restaurant]{
if self.cuisineTypes.count == 0 {
return list
}
let array: [Restaurant] = list.filter { (restaurant) -> Bool in
for cuisineName in self.cuisineTypes{
let isContained: Bool = restaurant.cuisineType.contains(cuisineName)
if isContained {
return true
}
}
return false
}
return array
}