问题
I am trying to use the Google Places Web Service through iOS (using swift). The reason I want to do so - I want to allow browsing places on a map, even if they are not nearby (the only search allowed using the iOS provided library). I also need to do it programmatically (since in one use-case I want to allow browsing the map, while in another use case - I want the places to be constant and not change based on the map camera). I can't use the iOS place picker, since I want the map to display information about the places on it (and in one use-case to not change)... (If you have a better design idea for this problem, let me know..)
When calling the Google Places API web service I get error 303. On the Google API web service it doesn't count the call, so I assume it failed, although 303 should be redirect.
I built a class for communicating with the web service (I save the server address in the configuration). This class is also structured in a way to provide the results immediately (and not in a callback).
Why do I get an error instead of a redirect? Is there any way to handle it? Any ideas to what can I do to avoid redirection at all?
Thanks!!
Here is (a template) of my code -- I reduced much of my logic and left the call for the web service (PlaceMarker is just a class I return, you can modify it to String):
class GooglePlacesWS : NSObject, NSURLConnectionDelegate, NSURLConnectionDataDelegate , URLSessionDelegate{
var DataReady : Bool!;
var Data : Foundation.Data!;
var opQueue : OperationQueue!;
var _responseData : NSMutableData!;
var error = false;
func getPlacesNear(_ point : CLLocationCoordinate2D, _ radius: Double)->[PlaceMarker]!
{
var retVal = [PlaceMarker]();
var locationJson = ["location": String(format:"%f, %f",point.latitude,point.longitude), "key": “MyKey”];
if (radius > 0){
locationJson["raidus"] = String(format:"%d",Int(radius));
}
// Fires the request to the server
var reply : String = HtmlToText(FireRequest(locationJson));
if reply == "" { return nil}
return retVal;
}
//MARK: Connection
var session : URLSession? = nil;
var dataTasks : URLSessionTask? = nil;
func sendRequestNew(_ request : URLRequest)
{
DataReady = false;
Data = nil;
let task = session!.dataTask(with: request, completionHandler: {data, response,error in
if (error != nil){
NSLog("Error reading data from web service: " + error!.localizedDescription);
self.Data = nil;
self.error = true;
self.DataReady = true;
}
else{
if (data != nil){
self.Data = data;
OSMemoryBarrier();
self.DataReady = true;
}
}
});
task.resume();
dataTasks = task;
}
// Changes a string to an HTML friendly tags (so the XML will transfer a string)
func textToHtml (_ htmlString : String) -> String
{
var retHtml = htmlString;
retHtml = retHtml.replacingOccurrences(of: "&", with: "&");
retHtml = retHtml.replacingOccurrences(of: "<", with: "<");
retHtml = retHtml.replacingOccurrences(of: ">", with: ">");
retHtml = retHtml.replacingOccurrences(of: "\"", with: """);
retHtml = retHtml.replacingOccurrences(of: "'", with: "'");
//retHtml = retHtml.stringByReplacingOccurrencesOfString("\n", withString: "<br>");
return retHtml;
}
// Changes an HTML string to a regular xml (changes the & tags to actual signs)
func HtmlToText(_ textString : String)->String
{
var retString: String = textString;
retString = retString.replacingOccurrences(of: "&", with:"&");
retString = retString.replacingOccurrences(of: "<", with:"<");
retString = retString.replacingOccurrences(of: ">", with:">");
retString = retString.replacingOccurrences(of: """, with:"\"");
retString = retString.replacingOccurrences(of: "'", with:"'");
retString = retString.replacingOccurrences(of: "<br>", with:"\n");
return retString;
}
// Sends the request to the server
func FireRequest (_ query : [String:String]) ->String
{
var retVal : String = "";
do{
// Builds the final URL request (adds the headers, and the WS addy)
let config :UserDefaults = UserDefaults();
//var myDict: NSDictionary?
if let path : String = config.object(forKey: "googleServerAddy") as? String
{
let url = URL(string: path);
//let theRequest = NSMutableURLRequest(url: url!);
var request = URLRequest(url: url!);
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.httpMethod = "GET";
request.httpBody = try JSONSerialization.data(withJSONObject: query, options: []);
sendRequestNew(request);
while (DataReady == false)
{
Thread.sleep(forTimeInterval: 0.01);
}
if (!error)
{
let result : Foundation.Data = Data!;
// Reads the response...
retVal = NSString(data: result, encoding:String.Encoding.utf8.rawValue)! as String;
}
else
{
retVal = "";
}
}
}
catch{
}
return retVal;
}
//MARK: NSURLConnection delegates
func connection(_ connection: NSURLConnection, willSend request: URLRequest, redirectResponse response: URLResponse?) -> URLRequest? {
return request;
}
override init() {
super.init();
opQueue = OperationQueue();
session = URLSession(configuration: URLSessionConfiguration.default, delegate: self, delegateQueue: opQueue);
}
}
回答1:
you could use Alamofire, works fine. used it for google streetview images
import Foundation
import Alamofire
import AlamofireImage
class GoogleData {
static let dataService = GoogleData()
func getGoogleImages(_ latitude: Double, longitude: Double, heading: Double, id: String, key: Int){
let url = "https://maps.googleapis.com/maps/api/streetview?size=400x300&location=" + String(latitude) + "," + String(longitude) + "&heading=" + String(heading) + "&fov=120&&pitch=-0.76&key=" + GOOGLE_API_KEY
Alamofire.request(url).responseImage { (response) -> Void in
print(response)
guard let image = response.result.value else { return }
print("alamo \(url) ")
let returnObj = [image]
ImageUtils.saveGoogleImageToFile(image , key: key, id: id)
NotificationCenter.default.post(name: NSNotification.Name(rawValue: googleGetImagesNotificationKey), object: returnObj)
}
}
}
to call it:
GoogleData.dataService.getGoogleImages(yourlatitude, longitude: your.longitude, heading: someHeading, id: someId, key: someKey )
回答2:
So the problem I had is sourced here:
let url = URL(string: path);
var request = URLRequest(url: url!);
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.httpMethod = "GET";
request.httpBody = try JSONSerialization.data(withJSONObject: query, options: []);
It appears - this solution forces a redirect.
I was not aware of the function addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed) so I wanted to use the httpBody for transferring the GET data, which apparently is wrong...
Changing the code to:
let actPath = path + "?" + query;
let url = URL(string: actPath);
var request = URLRequest(url: url!);
request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
request.httpMethod = "GET";
solved the issue for me.
notice query is the query for the get string -- something like
location=1.1, 2.2&radius=5&key=MY_KEY
来源：https://stackoverflow.com/questions/40157305/google-places-api-web-service-using-swift-returns-error-303