How to Location Bias Google Places Autocomplete?

Question

I am using this Tutorial by Google to implement Google Places Autocomplete into an iOS app with Swift but I am trying to restrict the results to a particular location as this link says is possible but for the life of me, I cannot see any place to do so..........

this is the view controller:

import UIKit
import GooglePlaces

class ViewController: UIViewController {

  var resultsViewController: GMSAutocompleteResultsViewController?
  var searchController: UISearchController?
  var resultView: UITextView?

  override func viewDidLoad() {
    super.viewDidLoad()

    resultsViewController = GMSAutocompleteResultsViewController()
    resultsViewController?.delegate = self

    searchController = UISearchController(searchResultsController: resultsViewController)
    searchController?.searchResultsUpdater = resultsViewController

    let subView = UIView(frame: CGRect(x: 0, y: 65.0, width: 350.0, height: 45.0))

    subView.addSubview((searchController?.searchBar)!)
    view.addSubview(subView)
    searchController?.searchBar.sizeToFit()
    searchController?.hidesNavigationBarDuringPresentation = false

    // When UISearchController presents the results view, present it in
    // this view controller, not one further up the chain.
    definesPresentationContext = true
  }
}

// Handle the user's selection.
extension ViewController: GMSAutocompleteResultsViewControllerDelegate {
  func resultsController(_ resultsController: GMSAutocompleteResultsViewController,
                         didAutocompleteWith place: GMSPlace) {
    searchController?.isActive = false
    // Do something with the selected place.
    print("Place name: \(place.name)")
    print("Place address: \(place.formattedAddress)")
    print("Place attributions: \(place.attributions)")
  }

  func resultsController(_ resultsController: GMSAutocompleteResultsViewController,
                         didFailAutocompleteWithError error: Error){
    // TODO: handle the error.
    print("Error: ", error.localizedDescription)
  }

  // Turn the network activity indicator on and off again.
  func didRequestAutocompletePredictions(forResultsController resultsController: GMSAutocompleteResultsViewController) {
    UIApplication.shared.isNetworkActivityIndicatorVisible = true
  }

  func didUpdateAutocompletePredictions(forResultsController resultsController: GMSAutocompleteResultsViewController) {
    UIApplication.shared.isNetworkActivityIndicatorVisible = false
  }
}

Answer 1

Just to clarify on NebojsaNadj answer wrt to OP - You can first set the bounds for bias using points to represent the bounding box. So to bias the autocomplete to Omaha, Nebaska, for example:

let northEastBoundsCorner = //Omaha's NE corner in CLCoordinate2D
let southWestBoundsCorner = //Omaha's SW corner in CLCoordinate2D
let bounds = GMSCoordinateBounds(coordinate: neBoundsCorner,
                             coordinate: swBoundsCorner)

So when you instantiate the GMSController you just set it's auto complete bounds to the above boundsmyGMSAutoCompleteController.autocompleteBounds = bounds. In the demo the OP referenced, it would be like this:

import UIKit
import GooglePlaces

class ViewController: UIViewController {

 // Present the Autocomplete view controller when the button is pressed.
 @IBAction func autocompleteClicked(_ sender: UIButton) {
    let autocompleteController = GMSAutocompleteViewController()
//Here's where you add it
    let northEastBoundsCorner = //Omaha's NE corner in CLCoordinate2D
    let southWestBoundsCorner = //Omaha's SW corner in CLCoordinate2D
    let bounds = GMSCoordinateBounds(coordinate: neBoundsCorner,
                             coordinate: swBoundsCorner)
    controller.autocompleteBounds = bounds
//back to demo code
    autocompleteController.delegate = self
    present(autocompleteController, animated: true, completion: nil)
  }
}
//see the demo for the rest of the code

Answer 2

Right in the documentation it says what class is used for this.

A GMSCoordinateBounds object biasing the results to a specific area specified by latitude and longitude bounds.

NOTE: You cannot completely erase everything outside of these bounds, if people search for the eiffel tower, they will still see it. but 99% of the results will probably be within these bounds. It's just a bias search.

Give the GMSCoordinateBounds class corner longitude and latitudes, and that's it.

And it's used like this:

let northEastBoundsCorner = CLLocationCoordinate2D(latitude: -33.843366,
                                            longitude: 151.134002)
let southWestBoundsCorner = CLLocationCoordinate2D(latitude: -33.875725,
                                            longitude: 151.200349)
let bounds = GMSCoordinateBounds(coordinate: neBoundsCorner,
                                 coordinate: swBoundsCorner) 
func placeAutocomplete() {
     let filter = GMSAutocompleteFilter()
     filter.type = .establishment
     placesClient.autocompleteQuery("Sydney Oper", bounds: bounds, filter: filter, callback: {(results, error) -> Void in
     if let error = error {
        print("Autocomplete error \(error)")
        return
     }
     if let results = results {
        for result in results {
            print("Result \(result.attributedFullText) with placeID \(result.placeID)")
        }
     }
}) }

Here is the url from the documentation where they are using it: Set the GMSCoordinateBounds of autocomplete