_Google Places for iOS 5 SDK
I am integrating the Google Places API into an iPhone app that I am building. I found an existing library that uses Google Local Search but that is deprecated. So I forked that solution and came up with Google Places Library.
As the story goes…when the application is configured to allow current location, the fun begins.
First configure your project to include the CoreLocation and the MapKit framework. I am using a single view project for this example but it can be any project really.
In the RootViewController I need to define some delegates. Since I will be embedding a UITableView and UISearchBar I need the following to be added: <UITextFieldDelegate, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate, CLLocationManagerDelegate, GooglePlacesConnectionDelegate>
UITableViewDelegate – will help populate the data on my table.
UISearchBarDelegate – will perform some interactions with the searching of places
CLLocationManagerDelegate – will get the location
GooglePlacesConnectionDelegate – will perform the main search
Once that is complete I can then add some outlets for my UI and set up some properties.
#import
#import
#import "GooglePlacesConnection.h"
@class GooglePlacesObject;
@interface RootViewController : UIViewController
{
IBOutlet UITableView *tableView;
IBOutlet UIButton *btnCancel;
IBOutlet UISearchBar *searchBar;
CLLocationManager *locationManager;
CLLocation *currentLocation;
NSMutableData *responseData;
NSMutableArray *locations;
NSString *searchString;
GooglePlacesConnection *googlePlacesConnection;
}
@property (nonatomic, getter = isResultsLoaded) BOOL resultsLoaded;
@property (nonatomic, retain) CLLocationManager *locationManager;
@property (nonatomic, retain) CLLocation *currentLocation;
@property (nonatomic, retain) NSURLConnection *urlConnection;
@property (nonatomic, retain) NSMutableData *responseData;
@property (nonatomic, retain) NSMutableArray *locations;
@end
Lets move on to the meat and potatoes of this app. Within the .m file I need to initialize some of my variables and get the GoogleConnection going.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
responseData = [[NSMutableData data] init];
[[self locationManager] startUpdatingLocation];
[tableView reloadData];
[tableView setContentOffset:CGPointZero animated:NO];
// [searchBar setDelegate:self];
googlePlacesConnection = [[GooglePlacesConnection alloc] initWithDelegate:self];
}
Do not forget to set the url connection to nil in the viewDidUnload.
Lets move to the Location Manager methods.
The first one returns a location manager or creates one if necessary
- (CLLocationManager *)locationManager
{
if (locationManager != nil)
{
return locationManager;
}
locationManager = [[CLLocationManager alloc] init];
[locationManager setDesiredAccuracy:kCLLocationAccuracyNearestTenMeters];
[locationManager setDelegate:self];
return locationManager;
}
The next method really starts the fun. In my case I am constructing a URL for the Google Places API. If you are not familiar with it you can find more about it here. The url takes the following parameters:
- key: required – your API key
- location: required – latitude/longitude around which to retrieve Place information. Location manager will help here
- radius: required – distance in meters. For the initial search I have 500, for the UISearchBar I moved it out to 1000.
- sensor: required – needs to be set to TRUE if came from a device with a location sensor
- keyword: optional – a term to be matched if searching
- language: optional – language codes
- name: optional – term to be matched against the names of the Places
- types: narrows the search to a specific type of place. Here is a list
At the end of all of this the url will look like this:
https://maps.googleapis.com/maps/api/place/search/json?location=-33.8670522,151.1957362&radius=500&types=food&name=harbour&sensor=false&key=AIzaSyAiFpFd85eMtfbvmVNEYuNds5TEF9FjIPI
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
if ([self isResultsLoaded])
{
return;
}
[self setResultsLoaded:YES];
currentLocation = newLocation;
//What places to search for
NSString *searchLocations = [NSString stringWithFormat:@"%@|%@|%@|%@|%@|%@|%@|%@|%@",
kBar,
kRestaurant,
kCafe,
kBakery,
kFood,
kLodging,
kMealDelivery,
kMealTakeaway,
kNightClub
];
[googlePlacesConnection getGoogleObjects:CLLocationCoordinate2DMake(newLocation.coordinate.latitude, newLocation.coordinate.longitude) andTypes:searchLocations];
}
The last methods are the setting of the objects and some clean up.
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error
{
NSLog(@"locationManager FAIL");
NSLog(@"%@", [error description]);
}
#pragma mark -
#pragma mark NSURLConnections
- (void)googlePlacesConnection:(GooglePlacesConnection *)conn didFinishLoadingWithGooglePlacesObjects:(NSMutableArray *)objects
{
if ([objects count] == 0) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"No matches found near this location"
message:@"Try another place name or address"
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles: nil];
[alert show];
} else {
locations = objects;
[tableView reloadData];
}
}
- (void) googlePlacesConnection:(GooglePlacesConnection *)conn didFailWithError:(NSError *)error
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error finding place - Try again"
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles: nil];
[alert show];
}
I am not going to dive deep into the GooglePlacesConnection class or the GooglePlacesObject. However I will say this, the GooglePlacesObject is just that. An object of the Google Place. It has an init that will take the dictionary object from the JSON results. The GooglePlacesConnection does the work of constructing of the URL and issuing the request. One thing to note, the only error checking on the Google Place request is if there are 0 results or an error with the URL or request. There are other status codes if you want to add them in if needed.
Back into the RootViewController.m, we now should have a locations NSMutableArray so we can now populate our UITableView.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)theTableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)theTableView numberOfRowsInSection:(NSInteger)section
{
return [locations count];
}
- (UITableViewCell *)tableView:(UITableView *)theTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"LocationCell";
// Dequeue or create a cell of the appropriate type.
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
// Get the object to display and set the value in the cell.
GooglePlacesObject *place = [[GooglePlacesObject alloc] init];
place = [locations objectAtIndex:[indexPath row]];
cell.textLabel.text = place.name;
cell.textLabel.adjustsFontSizeToFitWidth = YES;
cell.textLabel.font = [UIFont systemFontOfSize:12.0];
cell.textLabel.minimumFontSize = 10;
cell.textLabel.numberOfLines = 4;
cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;
cell.textLabel.textColor = [UIColor colorWithRed:0.0 green:128.0/255.0 blue:0.0 alpha:1.0];
cell.textLabel.textAlignment = UITextAlignmentLeft;
cell.detailTextLabel.text = place.vicinity;
cell.detailTextLabel.textColor = [UIColor darkGrayColor];
cell.detailTextLabel.font = [UIFont systemFontOfSize:10.0];
return cell;
}
We set the count of the array to the number of rows in section. We then get the locations object at the indexPath and set that to a GooglePlacesObject and populate the cell.
To handle the UISeachBar here is the code:
- (void)updateSearchString:(NSString*)aSearchString
{
searchString = [[NSString alloc]initWithString:aSearchString];
//What places to search for
NSString *searchLocations = [NSString stringWithFormat:@"%@|%@|%@|%@|%@|%@|%@|%@|%@",
kBar,
kRestaurant,
kCafe,
kBakery,
kFood,
kLodging,
kMealDelivery,
kMealTakeaway,
kNightClub
];
[googlePlacesConnection getGoogleObjectsWithQuery:searchString andCoordinates:CLLocationCoordinate2DMake(currentLocation.coordinate.latitude, currentLocation.coordinate.longitude) andTypes:searchLocations];
[tableView reloadData];
}
- (void)searchBarTextDidBeginEditing:(UISearchBar *)theSearchBar
{
[theSearchBar setShowsCancelButton:YES animated:YES];
tableView.allowsSelection = NO;
tableView.scrollEnabled = NO;
}
- (void)searchBarCancelButtonClicked:(UISearchBar *)theSearchBar
{
[theSearchBar setShowsCancelButton:NO animated:YES];
[theSearchBar resignFirstResponder];
tableView.allowsSelection = YES;
tableView.scrollEnabled = YES;
theSearchBar.text = @"";
[self updateSearchString:searchBar.text];
}
- (void)searchBarSearchButtonClicked:(UISearchBar *)theSearchBar
{
tableView.allowsSelection = YES;
tableView.scrollEnabled = YES;
[self updateSearchString:theSearchBar.text];
}
The second, third and fourth method handle the interaction with the UISearchBar itself. Each calls the updateSearchString method and passes in the text from the search bar. updateSearchString performs a similar search to the location manager search, except it is passing in the search string as well. If you look in the GooglePlacesConnection method I am also expanding the search radius to 1000 from 500.
That is it. You can find the source on github.
My next update will be adding a ‘pull to refresh’.
