Computed property is observable (i.e., they notify on change) and they are computed based on the values of other observables.
A computed property value is calculated based on the other observables properties. For example, we want to say Hello to the user who logged-in into your application, then we need to have the computed observable as like the above example.
It should look like the image below: Required functions: search function, navigation function, display folders path, ability to rename a file or folder name within the grid, ability to add new file or folder, ability to delete file or folder with confirmation dialog, display a different icon for a different file type, attach to an Enter and Esc key.
Here’s a simple model object: property changes, the effect will propagate out incrementally through the whole dependency graph with the minimum of callback-invoking, meaning a snappy user experience even with large data sets and low-end mobile devices.
knockout-projections is open source under the Apache 2.0 license.
Three main properties of Knockout JS As I told, the three main properties of Knocout JS are given below.
Observable is the property that automatically will issue notifications whenever their value changes Yes, Observable is a magic property of Knockout JS which will notify the underlying viewmodal when there is change happens in the property.
Basically computed observable property is readonly but KO provides the option to write into the computed observable property.
To make the computed observable writable, KO has different way, we need to pass a object with read & write callbacks.
As compared to any other Java Script engine or framework such as Back Bone, Java Script MVC, Ember or Angular, Knockout is a lightweight library while most of the others are frameworks.
That’s why Knockout usually is faster (it depends on OS and browser).
As we have bound the name property with the label's text attribute, the value is displayed at the label.
Extender in Knockout JS is nothing but adding a new feature to the existing observable property.
Any section of UI that should update dynamically (e.g., changing depending on the user’s actions or when an external data source changes) with Knockout can be handled more simply and in a maintainable fashion. It works without , or any other Java Script library, and it is compatible with all popular web browsers, such as Chrome, Firefox, Safari, Internet Explorer and Opera.