Mixins
Note: This documentation is for the old 0.8.0 version of A-Frame. Check out the documentation for the current 1.6.0 version
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.
<a-scene> |
The entity with red cube
will take the properties from the red
mixin and
the cube
mixin in that order. Likewise with the blue cube
. Conceptually,
the entities above expand to:
<a-entity material="color: red" geometry="primitive: box"></a-entity> |
Merging Component Properties
Properties of a multi-property component will merge if defined by multiple mixins and/or the entity. For example:
<a-scene> |
All of the geometry component properties will merge since they are included as mixins and defined on the entity. The entity would then be equivalent to:
<a-entity geometry="primitive: box; height: 10; depth: 2; width: 10"></a-entity> |
Order and Precedence
When an entity includes multiple mixins that define the same component
properties, the right-most mixin takes precedence. In the example below, the
entity includes both red
and blue
mixins, and since the blue
mixin is
included last, the final color of the cube will be blue.
<a-scene> |
If an entity itself defines a property that is already defined by a mixin, the entity’s definition takes precedence. In the example below, the entity includes both red
and blue
mixins and also defines a green color. Since the entity directly defines its own color, the final color of the cube will be green.
<a-scene> |