Mixins provide a way to compose and reuse commonly-used sets of component properties. They are defined using the
<a-mixin> element and are placed in
<a-assets>. Mixins should be set with an id, and when an entity sets that id as its mixin attribute, the entity will absorb all of the mixin’s attributes.
The mixin classes provide the actions that are used to provide the basic view behavior. Note that the mixin classes provide action methods rather than defining the handler methods, such as
.post(), directly. This allows for more flexible composition of behavior. -Official Django rest Framework Documentation-
Getting started guide using Sass exentsion Compass. Compass is very useful when dealing with CSS3 as it provides mixins to write 1 line in order to support every browser using CSS3 features. It is also great to include sprite images.