How to automatically find nearby locations using my location? - xcode

Question

I am VERY new to xcode but what i am trying to accomplish is when you open the app it shows a map and my location and the current food places that are around me. I dont have my own database for the locations i am trying to use google for this function. what i was able to do is find a tutorial but it has a search bar and when i search for something it shows me but i want it to automatically show me and not have the function of searching.
Is this possible? any help/tutorial is greatly appreciated. Thank you

Answer 1

You can try to use Place search api.
http://code.google.com/apis/maps/documentation/places/#PlaceSearches
They support a "restaurant" and "food" type.
http://code.google.com/apis/maps/documentation/places/supported_types.html
So you can remove the search bar and instead send a request to google places api with current location and types="restaurant" or types="restaurant|food".
You can get the results as JSON data wich you can easily use in your app.
Next step would be to make annotations and add them to a map.
__
Here are details on the first parts.
Once you get this working you can move on to getting an API-key for google places, get current position and then start adding json results to a map using map annotations. :)
The async url connection is the biggest part here. So once you get this working, you are well on your way to finding nearby locations.
To setup the JSON part..
Download a json library.. https://github.com/johnezang/JSONKit
Add JSONKit.h and JSONKit.m to your project. (add files.. or drag them over)
Add #import "JSONKit.h" (in your .m file)
Look in the final method below to see how to setup the variables and get data from json.
For the url connection part...
Based on: http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/URLLoadingSystem/Tasks/UsingNSURLConnection.html
PS: You would make a change later to use google places json api-url, api-key, current location and the "restaurant" type (to get the needed response in json from google).
Create a request:
- (void)viewDidLoad
{
// Create the request.
NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://www.google.com/calendar/feeds/developer-calendar#google.com/public/full?alt=json"]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
// create the connection with the request
// and start loading the data
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if (theConnection) {
// Create the NSMutableData to hold the received data.
receivedData = [[NSMutableData data] retain];
} else {
// Inform the user that the connection failed.
}
}
Then you need to implement the delegate methods.. (copy this into .m file)
This one is invoked when you get response (not the actual data, hence they reset it).
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
// This method is called when the server has determined that it
// has enough information to create the NSURLResponse.
// It can be called multiple times, for example in the case of a
// redirect, so each time we reset the data.
[receivedData setLength:0];
}
This one is invoked when data is received - can happen several times, so they append data each time.
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// Append the new data to receivedData.
[receivedData appendData:data];
}
Sometimes the connection would fail, then this delegate method is invoked - and you can present a message to the user (apple says to always inform users of what is happening)..
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
// release the connection, and the data object
[connection release];
[receivedData release];
// inform the user
NSLog(#"Connection failed! Error - %# %#",
[error localizedDescription],
[[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}
Finally, this method is invoked when the connection finished successfully. Now you have your complete data, and you save it to a variable. Here we also place the data into jsonDict.
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// do something with the data ...
// Your data is now stored in "receivedData",
// set up this mutable variable in the header file, then synthesize.
// in the .h file, inside the #interface block.:
//
// NSMutableData *receivedData;
// NSDictionary *jsonDict;
// }
//
// #protocol (nonatomic, retain) NSMutableData *receivedData;
// #protocol (nonatomic, retain) NSDictionary *jsonDict;
// And in the .m file, under the #implementation line.
// #synthesize receivedData, jsonDict;
// Log to test your connection
NSLog(#"Succeeded! Received %d bytes of data",[receivedData length]);
// Place the received data into a json dictionary
jsonDict = [receivedData objectFromJSONData];
// Get sections from your data
NSString *feed = [jsonDict objectForKey:#"feed"]; // asumes there is only one title in your json data, otherwise you would use an array (with dictionary items) ..look in your feed to find what to use.
// Log your data
NSLog(#"My feed: %#", feed);
// release the connection, and the data object
[connection release];
[receivedData release];
}
Try to get this going, then we can get back to using places search and adding results to a map.

Answer 2

Refer the following link
http://www.raywenderlich.com/13160/using-the-google-places-api-with-mapkit
The link shows the from the scratch development of map API project