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 20 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 7
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 ✓
The Hidden Garden 16 Joe Abercrombie, Ted Chiang, and Becky Chambers Fiction 30.44 € Tor Books ✓
The Ancient Ocean 17 Martha Wells, Ted Chiang, and Stanisław Lem Fiction 34.01 € Baen ✓
The Ancient Ocean 19 Frank Herbert Fiction 43.54 € Baen ✓
Scifi 7
Nonfiction 6