Apps can add elements to a design as part of an app element or as a native element.
An app element is a group of one or more elements that apps can modify after it's added to a design. They're more flexible than native elements but have a more complex lifecycle and some key limitations.
Benefits
- Create new types of elements by combining elements into unique combinations
- Store metadata on elements, allowing them to be edited with the app that created them
How app elements work
At their most basic, app elements are group elements that:
- Can't be un-grouped — that is, they're locked groups
- Can have metadata attached to them
Because app elements are group elements, they can be made up of multiple child elements. Unlike regular group elements though, app elements can contain a single element. To learn more, see Combining elements
Because app elements can have metadata attached to them, the element's settings — for example, color, rotation, etc — can be persisted on the element itself. This allows app elements to be re-opened and edited in the app that created them. To learn more, see Setting app element data.
When to use
In general, an app should create app elements if the app's usefulness would be limited by the use of native elements — for example, if it's important that the element is re-editable.
If your app won't specifically benefit from app elements, use native elements.
Limitations
- Users can't apply effects to app elements (or the elements within them).
- Users can't select the individual elements within an app element.
- Users can't un-group the elements within an app element.
- App elements can only be edited via the apps that created them.