iOS 7 Programming Cookbook

11.5. Sending HTTP GET Requests with NSURLConnection

Problem

You want to send a GET request over the HTTP protocol and perhaps pass parameters along your request to the receiver.

Solution

By convention, GET requests allow parameters through query strings of the familiar form:

http://example.com/?param1=value1&param2=value2...

You can use strings to provide the parameters in the conventional format.

Discussion

A GET request is a request to a web server to retrieve data. The request usually carries some parameters, which are sent in a query string as part of the URL.

In order to test a GET call, you need to find a web server that accepts the GET method and can send you some data back. This is simple. You may already know that when you open a web page in your browser, your browser by default sends a GET request to that end point, so you can use this recipe on any website of your liking.

To simulate sending query string parameters in a GET request to the same web service using NSURLConnection, use a mutable URL request and explicitly specify your HTTP method to GET using the setHTTPMethod: method of NSMutableURLRequest and put your parameters as part of the URL, like so:

- (BOOL)            application:(UIApplication *)application
  didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{

    NSString *urlAsString = <# Place the URL of the web server here #>;
    urlAsString = [urlAsString stringByAppendingString:@"?param1=First"];
    urlAsString = [urlAsString stringByAppendingString:@"&param2=Second"];

    NSURL