Application programming interfaces – or APIs – are an important programming concept to understand. And if you invest the time to learn more about these interfaces, it can help make your tasks more manageable.
One of the common types of APIs is a REST API. If you’ve ever considered getting data from another website, such as Twitter or GitHub, you’ve probably used this kind of API.
So why is understanding a REST API useful? How does it ensure modern business connectivity?
Before building or operating an API, or a REST API in particular, you should first learn what an API is. This article will walk you through the REST API principles, and how they grew into powerful applications.
APIs represent a set of definitions and protocols. You need them for app development and integration as they facilitate data exchange between two pieces of software, like an information supplier (a server) and a user.
APIs specify the content available to the client making the call from the producer that's returning the response.
Programs use an API to communicate, retrieve information, or perform a function. APIs allow users to work with the system to return their desired result.
To put it simply, an API acts as a mediator between users (clients) and resources (servers).
When users make API requests or visit an online store, they expect a fast response. So you need to optimize Magento TTFB (Time To First Byte) or use other performance enhancement strategies that work best for your CMS.
The reasons to integrate an API include:
RESTful refers to software architecture which stands for “Representational State Transfer”. You may have heard of it in the context of standardizing the use of information exchange systems (web services).
These web services utilize a stateless protocol to make textual representations of their online resources available for reading and processing. A client performs well-known HTTP protocol-based activities like fetch, update, and delete.
REST was first established in 2000 with the goal of improving performance, scalability, and simplicity by enforcing specific limits on an API.
It has gained popularity because of the opportunity to cover various devices and applications. Below you will find some of the purposes of using REST APIs.
There’s no specific client-side technology for REST as it suits diverse projects, such as:
As you won’t have to stick to a specific client-side stack, you can build any infrastructure for your company.
REST API calls are ideal for cloud applications due to their statelessness. If something goes wrong, you can re-deploy stateless components, and they can grow to manage traffic shifts.
An API connection to a service requires controlling how the URL is decoded. That’s why REST has become more useful in cloud services.
RESTful API architecture will become the norm in the future, thanks to cloud computing and microservices.
Data (such as images, videos, and text) embody resources in REST. A client visits a specific URL and sends a server request to receive a response.
A request (the URL you access) contains four components, which are:
--headeroption to send HTTP headers)
--dataoption with POST, PUT, PATCH, or DELETE requests.
The HTTP requests allow you to operate with the database, such as:
These operations stand for four possible actions, known as CRUD: Create, Read, Update and Delete.
The server sends the data to the client in one of the following formats:
Why should you prefer REST over other APIs, such as SOAP? There are numerous reasons, like scalability, flexibility, portability, and independence.
A separate client and server operation means that developers aren’t bound to any project parts. Thanks to adaptive REST APIs, they can develop each aspect without influencing another one.
REST APIs work only when the data from one of the requests is successfully delivered. They allow you to migrate from one server to another and update the database at any moment.
As the client and server act independently, the coders may swiftly develop the product.
Developers have to consider a rigid structure of some APIs, such as SOAP or XML-RPC. But REST APIs are different. They support a wide range of data types and may be written in practically any programming language.
The six REST architectural constraints are principles for designing the solution and are as follows:
This concept dictates that all API queries for the same resource, regardless of their origin, should be identical, that is, in one specific language. One uniform resource identification (URI) is associated with the same data, such as a user’s name or email address.
Another uniform interface principle states that messages should be self-descriptive. They must be comprehensible for the server to determine how to handle it (for example, the type of request, mime types, and so on).
The REST architectural style takes a peculiar approach to the client and server implementations. The thing is, they can be done independently and don’t have to know about the other.
For example, the client has only the uniform resource identification (URI) of the requested resource and can’t communicate with the server program any other way. On the other hand, the server shouldn’t affect the client software. So it sends the essential data over HTTP.
What does this mean? You can modify the client code at any moment without impacting the server’s operation.
The server code is in the same boat: changing the server’s side won’t affect the client’s operation.
You can keep client and server programs both modular and independent as long as each side knows what message format to deliver to the other.
What do we achieve by separating the user interface problems from the data storage constraints? We improve the interface flexibility across platforms and boost scalability.
Furthermore, each component benefits from the separation because it can evolve independently. A REST interface assists different clients in:
REST-based systems are stateless, meaning that the client state remains unknown to the server and vice versa. This constraint allows the server and the client to understand any sent message, even if they haven’t seen the preceding ones.
To enforce this constraint of statelessness, you need to use resources rather than commands. These are the nouns of the web. Their purpose is to describe any object you may want to keep or communicate to other services.
You can control, change, and reuse components without affecting the system as a whole, so the benefits of this constraint include achieving:
Note that each request should include all the information required to complete it. Client applications have to save the session state since server apps shouldn’t store any data linked with a client request.
REST requires caching client-side or server-side resources wherever possible. Data and response caching are critical in today’s world because it results in better client-side performance.
How does it affect a user? Well-managed caching can reduce or eliminate some client-server interactions.
It also gives the server more scalability options due to the smaller burden on the server. Caching increases the page load speed and allows you to access previously viewed content without an Internet connection.
The RESTful layered design structure is the next constraint under discussion. This principle involves grouping different layers with specified functions.
The REST API layers have their responsibilities and come in hierarchical order. For example, one layer may be responsible for storing data on the server, the second for deploying the APIs on another server, and the third for authenticating requests in another server.
These layers act as mediators and prevent direct interaction between the client and server apps. As a result, a client doesn’t know which server or component they address.
What does it mean when each layer performs its function before transferring the data to the next? It improves the API’s overall security and flexibility because adding, altering, or removing APIs doesn’t affect other interface components.
The most common scenario of using REST APIs is to deliver static resource representations in XML or JSON.
When you’ve understood REST API design and architectural constraints, you should know the issues to expect while employing this architectural style:
APIs should remain consistent regardless of the URL construction. But with the growth of possible combinations of methods, it’s harder to maintain uniformity in large codebases.
APIs require regular updating or versioning to prevent issues with compatibility. However, old endpoints remain operational, which increases the workload.
You can specify what resources are available to what user types. For example, you can determine which third-party services can access customer email addresses or other sensitive information and what they can do with these variables.
But the 20 different authorization methods that exist can make your initial API call difficult. That’s why developers don’t proceed with the project due to the initial difficulties.
Although RESTful APIs have a layered structure, there still may be some security concerns. For example, if an application isn’t secure enough due to a lack of encryption, it can expose sensitive data.
Or a hacker may send thousands of API requests per second, causing a DDoS attack or other misuses of the API service to crash your server.
A server may return a request with all the data, which may be unnecessary. Or you might need to run multiple queries to get the needed information.
There’s no surprise that APIs are predicted to streamline web-based communications in the future. Their purpose is to allow any web apps to interact and share data.
For example, they assist growing online businesses in developing robust and inventive systems. As the API architecture evolves, it adopts lighter and more flexible variants, which are critical for mobile apps and scattered networks.
So in this article you learned the basics of what you need to know about using REST APIs.