nested-resources
Nested resources
A resource that belongs to another can be nested under its parent, scoping every
view to the parent record, in the spirit of Active Admin's belongs_to.
MVC::Keayl::Admin.register(Post, {
belongs-to('author');
column('title');
field('title', :as<string>);
permit(<title>);
});belongs-to names a belongs-to association on the model. The admin reads the
target class and foreign key from the ORM reflection.
Nested routes and scoping
Alongside the standalone routes, the resource gains a nested set under its
parent: /admin/authors/:author-id/posts, /admin/authors/:author-id/posts/:id,
and so on. Within those:
the index, show, edit, update, and destroy relations are scoped to the parent, so a record under a different parent is a 404;
the breadcrumbs show the parent chain (Authors, the author, Posts);
the new button, row actions, and form post into the nested path;
a create fixes the foreign key to the parent, so a new record belongs to it.
The standalone routes still work and list every record. The nested resource is left out of the top menu; reach it from the parent's show page, which links to each resource nested under it.
Eager loading
includes names associations to eager-load on the index, avoiding a query per
row when a column or block reads an association:
MVC::Keayl::Admin.register(Post, {
includes('author');
column('author', :display({ .author.name }));
});