Alamofire Library
Alamofire is an HTTP network-based library which is used to handle the web request and response in iOS and MacOS. It is the wrapper class of URLSession and provides an interface on the top of Apple’s networking stack. It simplifies the common networking tasks like preparing HTTP requests and parse the JSON object.
The main advantage of Alamofire is that it is written entirely in swift and does not inherit anything from the AFNetworking library used for networking calls in objective C.
It provides the request and response methods, JSON parameter and response serialization, authentication, and many other features. Since Alamofire simplifies the HTTP networking calls in iOS projects. Before Alamofire, we were used to preparing all the requests by ourselves only. The multipart request and response were also a complicated process, including file uploading and downloading.
In this section of the tutorial, we will discuss the working and uses of the widely used networking library, Alamofire. We will set up a project and see how we can use Alamofire in it.
Setting up Alamofire in the iOS project
Alamofire can be installed in the project using Cocoapods or Carthage. Since we have used Cocoapods in this tutorial, we will stick to cocoapods for the installation. Alamofire project can be found on GitHub as https://github.com/Alamofire/Alamofire, where we can find the documentation regarding its installation.
However, let’s create a new project for network calls and name it as AlamoDemo. Here, we are saving it inside a folder named Alamofire on desktop.
After creating the project, open the terminal and change the directory to the project directory by the following command.
Initialize the Podfile by the following command.
Now, in the Podfile, add the following line to install the pods for Alamofire.
Now run the following command to install the pods, and after successful install, open the project xcworkspace file.
Basic network terminologies
In this tutorial, we have not discussed the basic network terminologies like HTTP, JSON, and REST APIs, which we are going to use in this section of the tutorial. However, this will provide you some exposure regarding the common network terminologies.
HTTP
HTTP stands for Hypertext Transfer Protocol that is an application protocol or set of rules. It governs the data transfer over the internet. HTTP provides the set of rules that every website follows to transfer the data from the webserver to the client’s web browser. Every URL on the internet is prefixed with HTTP of HTTPS. There are other application protocols, such as FTP, Telnet, and SSH. There are the following request methods defined by HTTP that is used by the client to indicate the action.
- GET: A GET request is used to retrieve data from the database. It does not alter the data on the server.
- POST: It is used to send the data to the server to perform an update action.
- HEAD: it is identical to the GET request. However, it only sends the headers and not the actual data.
- PUT: It is used to send the data to a specific location on the webserver.
- DELETE: It is used to delete the data from a specific location.
REST
REST stands for REpresentational State Transfer that defines a set of rules to design consistent and easy-to-use Web APIs. It defines some architecture rules that persist the states across the web requests that make the request cacheable and provide uniform access. As the Application developer, we do not need to track the state of data across the requests while integrating the REST APIs into the Application.
JSON
JSON stands for JavaScript Object Notation. It provides a human-readable mechanism to transfer data between two systems. In simple words, the REST APIs send the data in the JSON format, which needs to be parsed at the client’s side. JSON has a number of data types like string, Boolean, number, array, object, and null.
As an application Developer, our main task is to parse the JSON data coming through the API from the server. We need to convert our objects in memory to JSON and vice versa. For this purpose, we may use the JSONSerialization class or JSONEncoder and JSONDecoder classes. However, we may also use a number of third-party libraries for handling JSON like SwityJSON. The combination of HTTP, REST, and JSON provides an excellent combination to provide us the web services. However, the Alamofire library makes it easy to work with these services. However, with Alamofire set up in the iOS project, we will discuss how to handle the data through the get request using alamofire in the next section of this tutorial.