Grouped table

Group by publisher Group by genre
How this page is built the gem renders it — this is all you write

Grouping is a render-time arrangement, like the layout. Add group_by: :genre — the gem orders by the group key, splits the rows into collapsible groups (chevron in the header) and shows a per-group count. With 15 books, groups start collapsed beyond config.group_collapse_threshold (default 50), opening only the first; the open ones live in ?open=, so a half-expanded view is copy-pasteable.

app/views/groups/index.html.erb 
<%= crud_collection @books, group_by: :genre %>   <%# belongs_to, enum or a column %>

Read more: Grouping

Cover Title Author names Genre Price Publisher Active
Fiction 4
The Broken Engine 4 Liu Cixin, Ann Leckie, and Ursula Le Guin Fiction 12.63 € Vintage ✓
The Burning Machine 8 Margaret Atwood and Becky Chambers Fiction 38.02 € Del Rey ✓
The Ancient Tower 11 Ted Chiang, Ann Leckie, and Frank Herbert Fiction 40.82 € Gollancz ✗
The Endless Machine 14 Ann Leckie, Ursula Le Guin, and Joe Abercrombie Fiction 8.37 € Gollancz ✓
Scifi 5
Nonfiction 6
The Broken Archive 1 Frank Herbert, Ted Chiang, and Ann Leckie Nonfiction 9.59 € Orbit ✓
The Endless Mirror 2 Ann Leckie, Mary Shelley, and Ursula Le Guin Nonfiction 28.63 € Vintage ✓
The Endless Empire 5 Ann Leckie Nonfiction 25.88 € Vintage ✓
The Broken Garden 6 Stanisław Lem, Ursula Le Guin, and Iain Banks Nonfiction 19.85 € Orbit ✓
The Hidden Engine 13 Margaret Atwood and Frank Herbert Nonfiction 33.63 € Gollancz ✓
The Endless Garden 15 Ursula Le Guin, Joe Abercrombie, and Adrian Tchaikovsky Nonfiction 29.85 € Orbit ✓