The fundamentals of software development lay in the fact that systems can share data. REST has its full meaning as Representational State Transfer. It defines the set guidelines a developer should adhere to while creating an application programming interface.
The Restful API works to give the client a series of results once they link to the URL. For Restful API to work, one has to use the correct HTTP procedures. These procedures specify the operation that needs to be carried out with the API.
How Restful API Works
Exact Header Tag Match
The client sends a call to the server for a given resource. Usually, it is an HTTP request. The server receives the request and starts processing the response by checking the available cache resources that include the requested tag header.
The server sends the API’s response with the request’s contents and a status code of 200 if successful. The API renders the browser’s response and simultaneously caches the resource duplicate along with the header data.
Header Tag Has No Match
The server receives the client request and checks for the tag’s logic with the resource content available. The server redefines the header tag and sends new content to the browser with a 200 status code. The browser displays the new header tag and the newly generated value is incorporated into the response. The browser thus uses the header tag and updates its cache with new information.
When the HTTP request has the same header tag as an earlier search, the server sends an empty body to the browser with status code 304 to show no modifications have been made. The browser uses the duplicate cache data from the client’s device.
Users of Restful APIs
Before Restful was built, developers utilized the Remote Procedure Call to write an XML document to make a call. With the development of universal rules on the Restful API constraints, developers can integrate software.
Developers use the commands and protocols available in restful to create or build applications that are easy to use. With this API, developers do not have to create an application from scratch.
Business platforms heavily depend on communication. Through these APIs, e-commerce platforms can update, add, synchronize, delete or retrieve data from the platforms. The API enables the business to obtain clients’ information such as orders, type of product preferred and payment. They are also able to respond to clients by approving the orders and organizing for shipment.
Also, they can exchange information with owners of other e-commerce stores.
This API allows these platforms to explore new features in various applications and optimize these features’ benefits. Also, they can market and reach more clients by using information made available by the APIs.
In their quest to avail information to their readers, bloggers need to incorporate images in their content. This practice not only improves the value of the blog but also attracts more traffic to their site. Restful APIs have provided ways through which bloggers can insert images on their site. One of the common ways is through the use of applications such as Flickr that use Restful APIs.
Constraints of Restful API
According to Dr. Roy Fielding’s doctorate dissertation, RESTFUL must adhere to six constraints. However, take note that these are not restrictions but rather specifications to maximize RESTful API’s capability.
It is a guideline that operates in the philosophy that the client and the server should be differentiated from each other and develop independently. The principle helps to ensure simplified communication between clients and servers since only clients can request and respond to the queries.
Stateless attribute dictates that the client’s calls must be interpreted as new tasks and not stored in the server. Moreover, each request has the necessary data for the server to recognize and service the request. Stateless features drastically reduce the server memory size allowing many requests as the software develops without server overloads.
iii. Uniform Interface
This characteristic requires all calls and responses to follow a standard format of communication. The aim is to eliminate discrepancies in information mandatory requests updates whenever there are updates in the API. Many RESTful APIs have adopted the HTTP request format in data manipulation where:
• GET is used to retrieve data
• POST is for the creation of new resources
• PUT is employed to edit or update an existing resource.
• DELETE is applied when removing a resource.
iv. Layered System
Intermediary server layers are inserted in the architecture to include security protocols, load balancing, shared caches and proxies. Insertion of multiple layers allows the server to call other servers to respond to the client calls, thereby improving the functionality and scalability.
Response resources are required to be implicitly or explicitly classified as cacheable or non-cacheable. The duration of the cacheable response must also be indicated. Cache data is generally stored on the client’s device for quick loading of the site when a client revisits the site without having to fetch data again from the server. This trait eradicates client-server interactions, thereby improving performance.
vi. Code on Demand
This optional principle is the only one that allows client scripts or applets to be downloaded on the API in an executable form without the end-user awareness.
Use Case and Examples of Restful API
There is a specific methodology that the API follows for every request to ensure that the result is achieved.
For a user who requires to know how to:
• Dispatch an easily published push notification to a collection of contacts. The API dispatches a signal to send the notifications to the contact source.
• Use the Watson Campaign automation to publish messages. The API acquires a list of published notifications sorted by order of date and message identification. If the number of messages is many, a next page URL is availed so that the user can access the published messages.
• Dispatch short messages to a contact source; the API sets prerequisites to send the SMS and allows you to send the message.
Other use cases include mapping universal behaviors and sending messages that are personalized to opt-in contacts. Examples of Restful APIs are Google API explorer and public API.
Benefits of Restful API
RESTful API uses HTT. Standard format in calling and retrieving requests making it very easy to understand and use.
Restful API has enhanced performance since it allows cache functionalities that reduce parsing, marshaling and unwrapping data. Using JSON format as the primary response format enhances its scalability and performance.
Restful does not require users to have foreknowledge of procedure names or particular parameters in a specified order. Responses are returned using JSON, XML, YAML, among other formats hinged on the client’s calls.
Restful protects users as it encrypts the data transfer between the client and the server. The good coding practice avoids direct attacks ensures authentication by authorizing users before processing requests.
Cloud-based services are shifting the way everything works and with many applications taking advantage of the service such as Azure and Amazon. The Restful architecture incorporates this principle to allow applications to be programmed and make use of cloud services.
Mobile devices have become so popular and the push to make applications that can serve similarly to the web application is rising. Restful is not keen on the underlying device layer allowing seamless inclusion of mobile applications.
Understanding how the Restful application programming interface works is important for incorporation to your website or mobile application. The ease of use, coupled with the huge community available, makes Restful an ideal API choice. With internet and e-commerce market leaders such as Google, Amazon, eBay, Facebook and Twitter incorporating Restful, it is no doubt that this API is here to stay.