2013-04-29-mklocalsearch.md

title	author	category	excerpt	status
MKLocalSearch	Mattt	Cocoa	In all of the hubbub of torch burning and pitchfork raising, you may have completely missed a slew of additions to MapKit in iOS 6.1.	swift reviewed 2.0 November 12, 2015

Look, we get it: people are upset about Apple Maps.

What should have been a crowning feature for iOS 6 became the subject of an official apology due to its embarrassing inaccuracies and the removal of public transportation information.

In all of the hubbub of torch burning and pitchfork raising, you may have completely missed a slew of additions to MapKit in iOS 6.1. Namely: MKLocalSearch.

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MKLocalSearch allows developers to find nearby points of interest within a geographic region.

But before you go and rush into using MKLocalSearch, you'll have to know a few things about its friends. You see, MKLocalSearch has its functionality divided across MKLocalSearchRequest and MKLocalSearchResponse:

let request = MKLocalSearchRequest()
request.naturalLanguageQuery = "Restaurants"
request.region = mapView.region

let search = MKLocalSearch(request: request)
search.startWithCompletionHandler { (response, error) in
    guard let response = response else {
        print("Search error: \(error)")
        return
    }
    
    for item in response.mapItems {
        <#...#>
    }
}

MKLocalSearchRequest *request = [[MKLocalSearchRequest alloc] init];
request.naturalLanguageQuery = @"Restaurants";
request.region = mapView.region;
MKLocalSearch *search = [[MKLocalSearch alloc] initWithRequest:request];
[search startWithCompletionHandler:^(MKLocalSearchResponse *response, NSError *error) {
    NSLog(@"Map Items: %@", response.mapItems);
}];

MKLocalSearchRequest takes a naturalLanguageQuery, such as "Taxidermists", and an optional bounding geographic region to constrain results. In practice, the region is usually passed from an MKMapView.

MKLocalSearchResponse is returned in the eponymous block handler of MKLocalSearch -startWithCompletionHandler:, and returns an array of MKMapItem objects. Each MKMapItem contains information like name, phoneNumber, url and address information via the placemark property.

If you keep a reference to your MKLocalSearch object, you can optionally -cancel the request, such as on -viewWillDisappear: or the like.

Where's The Beef?

MKLocalSearch is a relatively straight-forward API (albeit perhaps worse off for eschewing a simpler single-class interface)... so what's the big deal?

API limits. Or rather, the lack of them. Let me explain:

Perhaps the most counter-intuitive things about MapKit in iOS 6 is that it's still widely used. Nevermind the "Apple Maps-gate" melodrama, MapKit, even with the introduction of impressive iOS mapping SDKs from Google and MapBox, developers are still using MapKit.

Part of this may be aesthetics, but a lot has to do with a certain level of home-field advantage, too. Because of MapKit's close ties to UIKit, it can be customized more easily and more extensively by third-party developers.

This brings us back to API call limits. When developing with another mapping SDK or geospatial webservice, licensing terms are almost necessarily going to be more limited than what Apple makes available for free. Free is a tough price to beat, and it's all-the-more compelling because there is no worry of going over API limits for tile loading or API calls.

Where Do We Go From Here?

With the introduction of MKLocalSearch, one can be hopeful of more first-party webservices being exposed in a similar fashion. Expanded geospatial search? Or perhaps first-party APIs to iTunes media streaming?

One can dare to dream, after all...

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MKLocalSearch provides a simple way to find local points of interest. Because of its no-hassle webservice integration and tight integration with MapKit, any location-based app would do well to take advantage of it.