Autofill city and state from zip code in iOS - ios

Question

I have three textfields in my view.
1. Zip code, 2. City and 3. State.
How to autofill city and state field from the zip code in iOS?
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSString *currentString = [textField.text stringByReplacingCharactersInRange:range withString:string];
int length = [currentString length];
if(length > 5)
{
return NO;
}
if(length == 5)
{
[self getCityAndState];
}
return YES;
}
- (void) getCityAndState
{
//How to use google (or any) api to autofill city and state in objective - c?
}

Answer 1

I try to avoid Google's services because they tend to charge at a certain level of usage. Here's the solution using Apple's frameworks:
#import <CoreLocation/CoreLocation.h>
#import <AddressBookUI/AddressBookUI.h>
- (void)didEnterZip:(NSString*)zip
{
CLGeocoder* geoCoder = [[CLGeocoder alloc] init];
[geoCoder geocodeAddressDictionary:#{(NSString*)kABPersonAddressZIPKey : zip}
completionHandler:^(NSArray *placemarks, NSError *error) {
if ([placemarks count] > 0) {
CLPlacemark* placemark = [placemarks objectAtIndex:0];
NSString* city = placemark.addressDictionary[(NSString*)kABPersonAddressCityKey];
NSString* state = placemark.addressDictionary[(NSString*)kABPersonAddressStateKey];
NSString* country = placemark.addressDictionary[(NSString*)kABPersonAddressCountryCodeKey];
} else {
// Lookup Failed
}
}];
}

Answer 2

Use the Google GeoCoding API to extract Information, if you want to send zip code to receive other information, use this:
NSString *strRequestParams = [NSString stringWithFormat:#"http://maps.googleapis.com/maps/api/geocode/json?address=&components=postal_code:%#&sensor=false",zipCode];
strRequestParams = [strRequestParams stringByAddingPercentEscapesUsingEncoding:NSStringEncodingConversionExternalRepresentation];
NSURL *url = [NSURL URLWithString:strRequestParams];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:#"GET"];
NSError *error;
NSURLResponse *response;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if (!response) {
// "Connection Error", "Failed to Connect to the Internet"
}
NSString *respString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding] ;
//NSLog(#"RECEIVED DATA : %#", respString);
If your zipcode variable is 32000, you will get the this JSON result:
You can parse this json to extract any information you want including Country, City, longitude, latitude etc

Answer 3

The answer by a-r-studios is spot on, since it doesn't introduce a dependency on Google's service.
However, I would also restrict the country code based either on the user's input or US-only if it makes sense. Not restricting it gives unpredictable results because the geocoder can return multiple hits from different countries.
#import <CoreLocation/CoreLocation.h>
#import <AddressBookUI/AddressBookUI.h>
- (void)didEnterZip:(NSString*)zip
{
CLGeocoder* geoCoder = [[CLGeocoder alloc] init];
[geoCoder geocodeAddressDictionary:#{(NSString*)kABPersonAddressZIPKey : zip,
(NSString*)kABPersonAddressCountryCodeKey : #"US"}
completionHandler:^(NSArray *placemarks, NSError *error) {
if ([placemarks count] > 0) {
CLPlacemark* placemark = [placemarks objectAtIndex:0];
NSString* city = placemark.addressDictionary[(NSString*)kABPersonAddressCityKey];
NSString* state = placemark.addressDictionary[(NSString*)kABPersonAddressStateKey];
NSString* country = placemark.addressDictionary[(NSString*)kABPersonAddressCountryCodeKey];
} else {
// Lookup Failed
}
}];
}

Answer 4

While the answers from alex_c and a-r-studios work well, if you don't feel like fussing with AddressBookUI or dictionaries, you can simply use the geocodeAddressString:completionHandler: method on the geocoder passing in the zip code alone which is sufficient for the lookup:
[[CLGeocoder new] geocodeAddressString:zip completionHandler:^(NSArray *placemarks, NSError *error) {
if (placemarks.count) {
CLPlacemark *placemark = placemarks.firstObject;
NSString *city = placemark.locality;
NSString *state = placemark.administrativeArea;
}
}];
In Swift:
CLGeocoder().geocodeAddressString(zip) { (placemarks, error) in
if let result = placemarks?.first {
let city = result.locality
let state = result.administrativeArea
}
}

Answer 5

Here is the Swift 3 version with all above corrections.
func zipToAddress(zip: String, onSuccess: #escaping (String, String, String) -> Void, onFail: #escaping () -> Void) {
let geoCoder = CLGeocoder();
let params = [
String(CNPostalAddressPostalCodeKey): zip,
String(CNPostalAddressISOCountryCodeKey): "US",
]
geoCoder.geocodeAddressDictionary(params) {
(plasemarks, error) -> Void in
if let plases = plasemarks {
if plases.count > 0 {
let firstPlace = plases[0]
print( "City \(firstPlace.locality) state \(firstPlace.administrativeArea) and country \(firstPlace.country) and iso country \(firstPlace.country)")
let city = firstPlace.locality
let state = firstPlace.administrativeArea
let country = firstPlace.country
onSuccess(city != nil ? city! : "", state != nil ? state! : "", country ?? "Not found")
return;
}
}
onFail()
}
}

Answer 6

Here is the Swift 4 version, with a proper optionals handling as a bonus.
Use this if you want to manually specify the country of the queried ZIP code.
private func zipToAddress(zip: String?, onSuccess: #escaping (String, String) -> Void, onFail: ((Error?) -> Void)?) {
guard let zip = zip else {
onFail?(nil)
return
}
let geoCoder = CLGeocoder()
let params: [String: Any] = [
String(CNPostalAddressPostalCodeKey): zip,
String(CNPostalAddressISOCountryCodeKey): "US"
]
geoCoder.geocodeAddressDictionary(params) { placemarks, error -> Void in
/// Read CLPlacemark documentation to see all available fields
if let place = placemarks?[0], let city = place.locality, let state = place.administrativeArea {
onSuccess(city, state)
} else {
onFail?(error)
}
}
}
And here is the solution based on the Nathan's answer.
Use this to query for the city and the administrative area, based on user locale.
private func localZipToAddress(zip: String?, onSuccess: #escaping (String, String) -> Void, onFail: ((Error?) -> Void)?) {
guard let zip = zip else {
onFail?(nil)
return
}
CLGeocoder().geocodeAddressString(zip) { placemarks, error in
if let result = placemarks?.first, let city = result.locality, let state = result.administrativeArea {
onSuccess(city, state)
} else {
onFail?(error)
}
}
}

Answer 7

static func zipToAddress(zip: String, onSuccess: (String, String) -> Void, onFail: () -> Void) {
var geoCoder = CLGeocoder();
var params = [
String(kABPersonAddressZIPKey): zip,
String(kABPersonAddressCountryCodeKey): "US",
]
geoCoder.geocodeAddressDictionary(params) {
(plasemarks, error) -> Void in
var plases = plasemarks as? Array<CLPlacemark>
if plases != nil && plases?.count > 0 {
var firstPlace = plases?[0]
var city = firstPlace?.addressDictionary[String(kABPersonAddressCityKey)] as? String
var state = firstPlace?.addressDictionary[String(kABPersonAddressStateKey)] as? String
var country = firstPlace?.addressDictionary[String(kABPersonAddressCountryKey)] as? String // US
onSuccess(city != nil ? city! : "", state != nil ? state! : "")
return;
}
onFail()
}
}
same with swift, I can't add this as comment(points doesn't enoght)