Since Apple's iTunes, APIs use GET requests to retrieve data. In this section, we will use the free http://httpbin.org service to show you how to make a POST request. The POST service that http://httpbin.org provides can be found at http://httpbin.org/post. This service will echo back the parameters that it receives so that we can verify that our request was made properly.
When we make a POST request, we generally have some data that we want to send or post to the server. This data takes the form of key/value pairs. These pairs are separated by an ampersand (&) symbol, and each key is separated from its value by an equals sign (=). As an example, let's say that we want to submit the following data to our service:
firstname: Jon lastname: Hoffman age: 47 years
The body of the POST request would take the following format:
firstname=Jon&lastname=Hoffman&age=47
Once we have the data in the proper format, we will then use the dataUsingEncoding() method, as we...