Ajax, the abbreviation for Asynchronous Javascript and XML, commonly refers to the web development technique that enables web pages to update consistently without reloading the complete page. Ajax allows web applications to be more interactive, responsive and user friendly. It is used widely in web 2.0 which is the second generation of web design and development emphasizing on social networking, collaboration and rich media.
Web 2.0 refers to websites and applications that utilize user generated content for end users. It is characterized by increasing user interaction and collaboration, more prevalent network connectivity and improvised communication mediums.
The basics of Ajax
Before diving deep into Ajax’s recent trends and developments, it is crucial to know its basics working functionalities. It does not fall into a single specific technology, instead a combination of multiple technologies, which allows data exchange among the web browsers and the server. This combination includes Javascript, a scripting language that runs in the browser and assists dynamic behavior and server communication. XML is a markup language that structures information for exchange XMLHttpRequest which is an object that enables the JavaScript for sending and receiving data from the server without interrupting the page display.
DOM (Document Object Model) is a representation of the webpage inside the browser that can be manipulated by the JavaScript in order to update the page content.
Through the utilization of these concepts, web applications can be developed by Ajax along with features like autocomplete, drag and drop, live search, and partial page refresh which are similar to desktop applications.
The framework and libraries of Ajax
A major challenge of Ajax development is that it has a requirement for several codes and compatibility testing across different platforms and browsers. In order to simplify and streamline the process of development, a lot of Ajax frameworks and libraries are created to offer ready made functions, tools, and widgets for common Ajax tasks.
Some famous examples include jQuery, which is a lightweight and a versatile library of JavaScript, Prototype, a framework of JavaScript that is responsible for the enhancement of the language along with an object oriented feature, it includes functional programming, and Ajax support, Dojotoolkit, a modular library of JavaScript, Angular JS, a framework of JavaScript that allows for the creation of single page applications by utilizing the MVC model ( Model-View-Controller) pattern and data binding. React is a JavaScript library that is focused on building user interfaces by utilizing reusable elements and a virtual DOM.
The design patterns and best practices of Ajax
With the evolution of the Ajax development in complexity and sophistication, it is becoming crucial to employ design patterns along with the best practices that ensures the quality, performance and the utility of web applications.
Among them are the progressive enhancement, that provides a fundamental functionality and user experience for the entire web browsers and devices while improving it by using Ajax features for compatible browsers, Restful web services, which uses HTTP methods for manipulating resources that are identified by URLs, JSON, a lightweight and human readable data format that is simple to generate than XML for the purpose of Ajax data exchange.
SPA is a web application that updates a single HTML page dynamically with Ajax requests without requiring reloading the entire page.
SEO is the process of optimizing the visibility and rankings of web pages in search engines which can prove to be difficult for Ajax applications that rely on dynamic content.
The security and testing of Ajax
Ajax development poses security and testing challenges that have to be addressed to ensure the credibility and safety of web applications. Common Ajax testing and security issues consists of Cross site request forgery, Cross site scripting, along with cross origin resource sharing. Unit testing and integration testing are also crucial practices for verifying the functionalities and accuracy of individual units or elements of code, as well as how they work together as a system.
The trends and innovations of Ajax
Ajax development is continuously evolving to fulfill the user expectations and technologies. For instance, Web sockets which is a protocol for enabling real time communication among the browser and server without polling or non polling. Web workers enable the Javascript to run in the background without affecting the user interface. Service workers play the role of a proxy between the browser and the network by enabling offline access, caching and push notifications. Web components are a set of standards that allows the developers to create reusable and customized HTML components that are encapsulated. PWAs or Progressive Web Apps are a type of web applications that provide installation, offline access, push notifications, along with device integration.