If you're looking for a way to write declarative views that only update the
changed parts of the DOM, take a look at Skeletor,
and in particular the ElementView class.
It does the same thing as the VDOMView in this package, but much better and
quicker.
Skeletor is a fork of Backbone that adds various new
features,
but you can continue using Backbone and just start using the ElementView.
This library provides a VirtualDOM-aware Backbone View, called
Backbone.VDOMView.
It depends on snabbdom for the virtual-DOM implementation.
To use it, extend Backbone.VDOMView. Then, instead of implementing a render
method in your view, add a toHTML method which returns the View's HTML as a
string (or alternatively, add a toDOM method which returns a single DOM element).
The HTML of the toHTML must be structured so that there's a root element
containing everything else. This root element is the view's top-level element,
in other words, it's the DOM node represented by the this.el or this.$el
attribute of the View.
React has a similar requirement that JSX returned by a component's render method
should have a root node which contains everything else.
The rest will then be handled by VDOMView, which will automatically
generate a diff between the view's current DOM element and new virtual-DOM
node and then patch the actual DOM with this diff.
For example:
const MyView = Backbone.VDOMView.extend({
tagName: 'span',
className: 'vdom-span',
toHTML () {
return this.template(_.assign(this.model.toJSON()));
}
});
One important difference between Backbone.VDOMView and Backbone.View
that should be noted is that the HTML being rendered (in the case of
Backbone.VDOMView this is done in the toHTML method) should include
the root element of the view.
So in the example above toHTML should return <span class="vdom-span"> ... </span>
as the outer part of the HTML string.
This is different from normal Backbone.View classes, where your template will only return the inner part of the view element.
Snabbdom implements non-core functionality in separate modules.
Backbone.VDOMView makes use of all Snabbdom's modules except for the
eventlisteners module.
The eventlisteners module allows you to add event listeners
when creating a virtual node via the h method.
However Backbone.VDOMView doesn't use the h method of Snabbdom at all (it
doesn't even include the code for it). Instead, it expects you to render the
HTML for the view in the toHTML method, for example by using an underscore or
lodash template.
There's therefore no way to attach these event listeners.
This way of registering event listeners is also in contrast to Backbone's declarative way of registering events, which is more the "Backbone way".
Backbone.VDOMView will make sure that these declaratively registered event listeners will remain active whenever the View's DOM representation changes.
Backbone.VDOMView will call two lifecycle methods (if they exist).
These are beforeRender and afterRender and are respectively called
before and after toHTML is called.
Backbone can be used without jQuery by using Backbone.NativeView instead of Backbone.View.
If Backbone.NativeView is available, then the VDOMView will use that instead of Backbone.View.
Backbone.VDOMView is used in converse.js.
If you have any questions, feel free to create an issue or contact me directly.