What is Knockout.js?
1. Knockout.js is a MVVM framework
Knockout.js offers the MVVM or Model – View – View Model application design architecture. Let us have a look at the definition of these terms.
Model – A Model represents data or information. It stores information but not behaviors or services that manipulate the information. It is done with the help of View and View Model as they both are interlinked through a two-way data binding mechanism.
View – A View is an actual representation of the data for the end user. A view is an HTML template having Knockout bindings. The view uses data-bind attributes to display and edit data. It contains HTML elements such as buttons, images, grids, links and more.
MVVM frameworks are specifically suitable for developing dynamic user interfaces. MVVM simplifies application development by achieving separation of concerns, I.e. GUI (graphical user interface) rendering logic from application logic.
2. Built-in Templating
Knockout.js provides DOM-based templating and by default uses HTML as its templating engine. But, it also supports other string-based templating. Templating allows applications to render views that are modular and reusable. With Knockout.js, one can perform DOM or string-based templating for modularizing views and rendering them in a programmed way.
Knockout.js also allows creating templates to render HTML for a single element or for every element in an array. This makes code organization pretty neat.
3. Declarative Binding
Knockout.js is quite useful since it allows embedding data binding expressions in your HTML. It allows associating DOM elements with model data using a simple syntax. Knockout.js is a data-binding library and it allows you to create custom bindings inside data-bind. Moreover, it offers declarative binding to connect parts of your UI to your data model.
In short, Knockout.js allows implementing custom behaviors as new declarative bindings for easy reuse in just a few lines of code.
4. Two-way Data Binding
Its two-way data binding mechanism between data model and UI means that any changes done to the data model are automatically reflected in the UI and vice versa. UI elements of an HTML page reflect changes done to the Data Model by updating DOM automatically. Moreover, Knockout.js allows managing the relationships between the view components.
5. Dependency Tracking
Knockout.js automatically tracks dependencies and updates the right parts of the user interface. It offers a simple way to manage complex, data-driven interfaces without relying on or writing event handlers and listeners for dependency tracking.
In Knockout.js, computed observables are used to define data fields. Declarative bindings are simply implemented as computed observables. So, when a binding reads the value of an observable, it causes the binding to re-evaluate if the observable changes.
Knockout.js is a free and open-source project maintained by Steve Sanderson. Though, it is backed by a small community of developers, Knockout.js is steadily increasing in popularity. There is a huge collection of online tutorials, app examples and documentation on its website. Moreover, you can also find information on web development with Knockout.js on Stack Overflow.
7. No Dependencies