Single property components have to return the default value when the …

[dmarcos]

No description provided.

[ngokevin]

Going to assume work-in-progress based on discussion yesterday.

[dmarcos]

The code is simpler now and works as expected but It introduces a wrinkle in the consistency of the system that I don't know how to do differently. Look at the following entity with a single property component called dummy with true as default value.

  <a-entity position="" rotation="" scale="" visible="" dummy=""></a-entity>

position, rotation, scale and visible are default components so they're not really defined on the entity (a mixin would take precedence) On the contrary dummy is not a default component and hence really defined on the entity. When calling getAttribute default and non default components will produce different values:
entityEl.getAttribute('dummy') === true
entityEl.getAttribute('position') === undefined
entityEl.getComputedAttribute('position') === { x: 0, y: 0, z: 0 }
Does it make sense?

[dmarcos]

After discussion with @ngokevin this is how the API behaves with the latest changes. Given a single property component dummywith a default value true and the following entity:

<a-entity dummy></a-entity>

These are the values returned for the components

el.getAttribute('dummy') === true;
el.getAttribute('position') === null;
el.getComputedAttribute('position') === { x: 0, y: 0, z: 0 };

The only inconsistency left it's when opening the DOM inspector the entity above will appear as:

<a-entity position="" rotation="" scale="" scale="" visible="" dummy></a-entity>

When calling getAttribute on those components you would expect to get the default values as it happens with dummy. Default components will return null instead because they're not really defined on the entity element despite of being shown as attributes. To retrieve the value of the default components one has to call getComputedAttribute. We can live with this small inconsistency for now and revisit the getAttribute / getComputedAttribute API for next version.

[ngokevin]

Don't need to assign to this.attrValue here since it gets replaced.

[ngokevin]

r+