The knockout.js framework is a minimalist JavaScript framework for developing web applications. HTML elements can be bound to any data model using this JavaScript library. The main purpose of the framework is to create a multi-dimensional, rich and responsive user interface as well as cleaner underlying data models. No matter what kind of client-side or server-side technology you use, Knockout.js works. Many popular websites use Knockout.js. A variety of approaches are available today that can be used to develop an effective website. The type of framework being employed usually determines these approaches.

Most modern website development company in usa is done using MVC or MVVM.  JavaScript’s knockout.js implements the MVVM pattern with templates based on the MVVM pattern. A number of advantages are offered by Knockout.js’ MVVM architecture design.  And many features will make you choose Knockout.js for your web development.

Background

Today’s web applications are built using JavaScript, which is extremely important. For a while, data validation was done from the client with just a few JavaScript lines. JavaScript helps create responsive, robust web interfaces not only with data validation but also with data validation. This is why new JavaScript frameworks and libraries are released day by day. Developing smart applications means adopting these features and integrating them into our applications.

What is Knockout.js?

We have been hearing the Knockout.js for some time now, so what is this Knockout.js? A Javascript library called Knockout facilitates the creation of desktop-like web UIs. Steve Sanderson, an employee of Microsoft, developed and maintained it. Users interact with KO simplified, and data sources can be modified while responsive. With the help of this mechanism, the data model is linked to the UI in a simple two-way manner, which makes it relatively easy to synchronize these two components.

So let us now dig deep into the features of Knockout.js to understand whether it is something worth trying out or not.

Features of Knockout.js

MVVM Framework

The first and foremost feature would be that Knockout.js has an MVVM framework. What is MVVM?

An MVVM architecture separates UI code from non-UI code by using a model-view-ViewModel pattern. You define your user interface declaratively in XAML using data binding. You then link your UI to the data and commands contained in other layers. A data binding infrastructure maintains data synchronization and routes the user’s input to the appropriate authorities while synchronizing the UI and the linked data. With data binding, different kinds of code are less dependent on each other because of the loose coupling it allows. Changing one code unit (method, class, control, etc.) without causing unintended side effects in another is made easier.

Decoupling is an example of the separation of concerns, a design pattern with many applications. MVC and MVP together are known as the MVVM pattern, combining the best of both worlds. MVVM can use both the separation of concerns benefits of MVC and the data binding capabilities of MVP. The MVVM approach focuses only on the user interface, leaving the server to handle any business logic and the presentation layer to handle any presentation logic. There are three parts to MVVM: Model, View, ViewModel

Model: Holds application data. User entered data will be saved to a Model when entering it through UI elements. Hence, we can consider it the data element of the pattern.

View: The view provides data to the user about the model. Views include user-facing elements. User Interface structure/layout is presented to the user through the User Interface.

ViewModel: Connector between Model and View. Primarily responsible for establishing communications between them. It stores data as well as performs functions. Those functions modify the data, which is reflected in the user interface. As data changes, the UI also changes, and when the UI changes, the data changes as well. Viewpoint will take care of it for us with the help of data binding.

The main advantages of MVVM can be summed up as follows

• Allow designers and developers to work in a more flexible manner
• Unit testing should be thorough
• To enable the ability to change user interfaces without needing to refactor the rest of the codebase
• Provide more re-usability for UI components

Relation between ViewModel and View

When implementing MVVM to your web application, you may face how many ViewModels are required for a view and vice versa. This means what kind of relationship is needed between a view and the model/ViewModel. Market opinions are few and far between:

• From One-View-Model to One-View-View
• ViewModels with many views
• Models with many views in one view

Neither hard nor fixed rules apply here. Many people fully support every view having a single ViewModel and every ViewModel having a single model. Doing so reduces complexity and allows us to organize code better.

Templating, which is built-in

The template engine in Knockout.js is DOM-based, and by default, uses HTML as its templating language. Other string-based templating languages can also be used. The use of templates allows applications to render views that can be reused and rearranged. Knockout.js will enable one to create DOM or string-based templated views and generate them in a programmed way using DOM or string-based templating. You can also create templates for HTML rendering for a single element or all elements in an array with Knockout.js. The code can be organized much more efficiently this way.

The decelerative binding

When using a JavaScript client with a business application or REST service, a client-side HTML document is often constructed to present data to the user. jQuery is most commonly used to generate HTML on the client-side by JavaScript developers. It often leads to large chunks of complex code being written. Data binding expressions can be embedded in your HTML thanks to Knockout.js. The library provides a simple syntax to associate DOM elements with model data.  Many font end devopment company uses knockout.js for this purpose.

A data-binding library, Knockout.js, can make custom bindings within the data-bind. Also, declarative bindings allow you to connect your UI to your data model. With Knockout.js, you can implement custom behaviors as new declarative bindings so that they can be reused easily with just a few lines of code.

Data Binding in both directions

A two-way data binding mechanism between the database and the user interface means that changes made to the database are automatically reflected in the user interface and vice versa. By updating the DOM automatically, HTML elements reflect changes made to the Data Model. As well, Knockout.js provides the ability to manage relationships between components on a view.

Flexible

Declarative bindings are used to implement custom behaviors, which can be reused in just a few lines of code. The technology behind Knockout is also very adaptable and can be used with a wide variety of other libraries and technologies.

Refreshing The UI automatically

UI changes (view model changes) are automatically reflected in the view model.

Tracking dependencies

With Knockout.js, dependencies are tracked automatically, and the right parts of the user interface are updated. With this solution, you don’t have to write event handlers and listeners for tracking dependency relationships. It offers an easy way to manage complex, data-driven interfaces. It is the observables that make Knockout.js possible. Subscribers are notified when they change, and dependencies are automatically detected. Data fields are defined using computed observables in Knockout.js. Knockout.js defines data fields as computed observables. Declarative bindings are defined as computed observables. As a result, whenever a binding reads a value from an observable, it reevaluates the detectable changes.

It’s open-source

Steve Sanderson is the creator of the open-source project Knockout.js. Knockout.js was initially backed by a small developer community but gained traction over time. The website offers an excellent collection of tutorials, examples, and documentation. As well as Knockout.js information on Stack Overflow, Stack Overflow provides information about web development.

There are no dependencies

Unless otherwise specified, Knockout.js requires no dependencies. It also does not need jQuery, Prototype.js or any other JavaScript library. Besides being trivially extensible, it is cross-browser compatible and supports various browsers, such as Internet Explorer, Firefox, Safari, Google Chrome and Opera.

Comparing Knockout.js and jQuery

jQuery and Knockout are comparable JavaScript libraries. jQuery uses DOM manipulation to handle DOM manipulation, while Knockout employs the MVVM framework. Knockout is designed to make app development easier by tying raw data to a model, similar to how jQuery is designed to make JavaScript more developer-friendly. Knockout.js also supports jQuery and MooTools, two popular Web technologies.

CONCLUSION

Despite what this article briefly touches upon, Knockout.js is extremely powerful. You might access your data by using a web API that serves it as JSON data in a real-world application. In JavaScript, we would interpret this JSON as an object and could use it as a data model incorporated into the View Model. An input of some of the returned data can modify the view.  The key thing to remember is that Knockout.js is 100% JavaScript. This means that if it’s possible in JavaScript, it’s also possible in Knockout.js. So if you know how to use Java, then Knockout is simple for you to use.

Author Bio:- Prashant Pujara is the CEO of MultiQoS Technologies, a leading website and Mobile App Development Company specialized in android and iOS app development. He has more than 10 years’ experience in app & web development with a strong focus on mobile app development for all kinds of platforms including iOS and Android.