When developing a page type or component type, Page Designer developers can preassign components to regions. When a merchant creates the page in the Visual Editor, the preassigned components are already in the region. The merchant can remove or modify the preassigned components as necessary.
Why: Preassigning a region with components makes it easier for a merchant to create a page. For example, a page layout for a Product List Page can have a preassigned Product Grid component in the main region of the page. When the merchant creates a page using the Product List Page layout, the Product Grid is already in the main region. The merchant immediately knows that the Product Grid component is the appropriate component to use on the page.
You can also preassign a Promotional Content component to one of the Product Grid’s own regions. Populating the Promotional Content component guides the merchant to use the component to highlight a particular promotion within the grid of product tiles on the page.
Preassigning a Product Tile component to a region within a Carousel component is another good use case. When merchants add the Carousel component to a page, the Carousel already contains a Product Tile component, making it clearer to the merchant how to configure the Carousel.
How: The developer uses the default_component_constructors property in the meta definition file for a page
type or a component type to indicate which components are preassigned to a region.