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 10 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 2
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 ✓
Scifi 4
The Silent Tower 3 Stanisław Lem and Martha Wells Scifi 43.93 € Vintage ✓
The Burning Machine 7 Octavia Butler Scifi 10.40 € — ✓
The Hidden Dune 9 Iain Banks Scifi 42.43 € Orbit ✓
— The Broken Dune 10 Liu Cixin, Margaret Atwood, and Martha Wells Scifi 13.54 € Del Rey ✓
Nonfiction 4
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 ✓