We are building a series of applications for the IPhone (IOS5), where we use reverse geocoding. Most of the time, CLGeocoder returns a range for the address number (eg. "someaddress 2-5"). We want to retrieve the exact street number for every reverse geocoding request.
As I have come to understand, this is not controlled by me as a developer but rather by Apple, which makes a call to Google and returns the results (the range of street numbers). Has anybody else encountered the same problem and found a solution?
One solution I was advised to do is purchase the google maps API for business. In its documentation it states that it offers "advanced geocoding", but no details are given for reverse geocoding and street numbers. Has anybody had any experience with this API?
Another thing that comes in mind is to use some third-party service that does reverse geocoding. But the thing I am not sure is if Apple will accept it. Does anybody has to suggest a third-party service that does reverse geocoding and returns the exact street number for a given position on the map?
Thank you in advance
It looks like GeoNames would fit your needs well.
From the Wikipedia page:
GeoNames is a geographical database available and accessible through
various Web services, under a Creative Commons attribution license.
I myself have been using CLGeocoder, and haven't experienced any issues with it returning a range of street numbers.
I am trying to find the long and lat of a city on the iphone. Say the user is searching for London, I would call some function that would retrieve the long and lat of London. I have looked on the web and found you can use a Google API but there must be an Apple function somewhere to handle this?
I have come accross the MKReverseGeocoder which takes the long and lat and tells you what city you are near. e.g.
// reverse geocode the user location
geocoder = [[[MKReverseGeocoder alloc] initWithCoordinate:mapView.userLocation.location.coordinate] autorelease];
If it can reverse the process there must be some form of MKGeocoder class?
but there must be an Apple function somewhere to handle this
Why must there be? Because there isn't.
There are a number of web services you can use (e.g. Google) or you could download a place name database such as http://www.geonames.org/ and import it into your app. It's probably best to import it into an SQL database which you can then search from your app.
See OpenStreetMap. It gives you more flexibility in accessing its data. You could pre-populate a CoreData store with the informations you need.
There are some api-clients, i.e. route-me or cloudmade.
The iOS5 SDK has added support for both forward and reverse geocoding. Take a look at at the CLGeocoder class class for more info.
First, give up that there "must be" an Apple way. There really isn't. If you don't believe me and my nearly 2k of experience points, listen to Ole and his 13k.
There are three services I've seen.
I tried Google's geocoding API. It's decent, but a bit complicated, and they throttle your queries pretty harshly.
Then I tried MapQuest's, which I found to be surprisingly excellent. I have two apps bound for the app store in the next month or so that use MapQuest's API.
Then I found Geonames, which I'm very impressed by but haven't had the opportunity to use yet. Note that Geonames DOES allow you to download their data, so if you really need network-free service, this might be a solution.
Apart from that, you're going to be calling something off the device. Which, by the way, you are when you use MKReverseGeocoder--that's just a wrapper around Google's reverse geocoding service.
In our iPhone application we have a requirement to display UK County and Area name of a location ( we have latitude and longitude) . Initially we used MAPKit framework (reverse geocoding) to get this information. But during testing we found that we are not getting correct data from Google always.
Can somebody suggest any alternative method to get this information ? We are ready to use paid services also.
You can take a look at CloudMade. They have pretty decent solutions for anything map service related. They use source from OpenStreetMap but you can do all sorts of customization to the maps. Another option is through Bing maps. It looks neat but I haven't tried it myself.
Does anyone know the best way to use the iPhone location services (lat/long) to determine the zip code+4 of the user? Does MKReverseGeocoder have the ability to pull back zip+4?
Thanks!
-tony
My favorite place to go for anything having to do with geocoding is geonames.org.
You may be able to use a free Reverse Geocoding service to do this for you.
Google has such a service: http://code.google.com/apis/maps/documentation/services.html#ReverseGeocoding
Alternately, this Google Groups post has a listing of other Reverse Geocoding services: http://groups.google.com/group/Google-Maps-API/web/resources-non-google-geocoders?pli=1
Apple's documentation says that the MKPlacemark that MKReverseGeocoder only returns a five-digit zip code. You may have to use an outside reverse geocoder as described in the other answers to get the extra four digits.
Update: iPhone SDk 3.0 now addresses the question here, however the NDA prevents any in depth discussion. Log in to the iPhone Dev Center if you need more info.
Ok, I have to admit I'm a little lost here.
I am fairly comfortable with Cocoa, but am having trouble picking up the bit of javascript needed to solve this problem.
I am trying to send a request to Google for a reverse geo code.
I have looked over the Google documentation I have viewed here:
http://code.google.com/apis/maps/documentation/index.html
http://code.google.com/apis/maps/documentation/geocoding/
Even after a rough reading, I am missing a basic concept:
How do I talk to google? In some examples, they show a url being sent to google (which seems easy enough), but in others they show javascript. It seems for reverse geocoding, the request might be be harder than sending the url with some parameters (but I hope I am wrong).
Can someone point me to the correct way to make a request? (In objective-C, so I can wrap my head around it)
UPDATE - iPhone 0.3 includes MapKit, which will hopefully be significantly faster than using the JS API. The blurb says that it will include reverse geocoding.
You can't make a request directly in objective-C, at least not within the terms of the Google API. The Google API is written in Javascript. You could use an objective-c to JS bridge, as the Google Maps Component does, but that doesn't really solve the issue - you're still making JS calls!
Unfortunately, that means you
a) need to use a webview
b) need to use the JS API which is slow... compare with the Google Maps application which uses a completely different OTA protocol (try packet sniffing it).
The Google Maps Component is, however, a useful tutorial in how to make simple calls to the API.
I have created SVGeocoder, a simple forward and reverse geocoder class for iOS. It uses the Google Geocoding API, returns SVPlacemark objects (an MKPlacemark subclass with a coordinate property) and uses blocks.
This is how you geocode an address string:
[SVGeocoder geocode:addressString
completion:^(NSArray *placemarks, NSError *error) {
// do something with placemarks, handle errors
}];
You can also reverse geocode a coordinate like this:
[SVGeocoder reverseGeocode:CLLocationCoordinate2DMake(45.53264, -73.60518)
completion:^(NSArray *placemarks, NSError *error) {
// do something with placemarks, handle errors
}];
The easiest way to get a Google map using Cocoa is to use the "Static Maps API". In practice, you need to prepare an NSURL that you use to contact Google. You get back your map as NSData, that you transform to an NSImage. Note that you can do both geocoding and reverse geocoding. You can also embed markers on the map. However, you loose the full controls you have access to if you use their JavaScript API.
Take a look at their reference guide here:
http://code.google.com/apis/maps/documentation/staticmaps/
Now that apple have release the MapKit API for OS 3.0, I think your question has been answered. Having looked at the API docs, I can see a heck of a lot of potential! I still would like to see reverse geocoding webservice from Google, but Yahoo will do in the meantime.
For your information: The reverse geocoding API from Google for requests by XML isn't public, so it's illegal to use. The only legal way is going through their JavaScript-API, which as you found out is harder to do in Cocoa than to simply send an HTTP request.
Alternatives: Reverse geocoding with simple XML/JSON requests is also available from Geonames or Yahoo.
Since iOS5 we have the following options as stated in the development doc:
* "A geocoder object uses a network service to convert between latitude and longitude values and a user-friendly placemark, which is a collection of data such as the street, city, state, and country information. Reverse geocoding is the process of converting a latitude and longitude into a placemark. Forward geocoding is the process of converting place name information into a latitude and longitude value. Reverse geocoding is supported in all versions of iOS but forward geocoding is supported only in iOS 5.0 and later."*
You can now use a CLGeocoder object.
Also try to take a look at google maps component.
Actually, I did not meant reverse geocoding as "translating a point into a human-readable address", but rather visualizing a point using a Google Map (that can also, depending on the accuracy level, show a human-readable address). This is the basic functionality that was required.
In practice, I just wanted to suggest the static maps API as a clean and fast way to:
1) given the coordinates obtained from the iPhone GPS sensor, retrieve a Google Map showing the point
2) given an address, transform it in the corresponding geographical coordinates and then use the coords to retrieve a Google Map showing the address given
Both are possible using simple NSURLs involving the staticmap and geo services
http://maps.google.com/staticmap?
http://maps.google.com/maps/geo?
passing of course the needed parameters to provide a suitable query string.
Kind regards
The big issue of course, is that the license agreement of both google and yahoo state you can't use these API's in "commercial applications". would hate to pub an app on the app store only to have it taken down and sued by yahoo or google. In reading the iPhone 3.0 map api and associated license this isn't mentioned but if you want an app to run on phones not upgraded....
Is there an answer for this that won't get one in trouble?
http://blog.cloudmade.com/2009/06/12/how-to-get-forward-geocoding-in-iphone-mapkit/
CloudMade seems to be an open-source map/location provider - the above blog post lists details on how to get forward geocoding.