Grouped table
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 | ✓ | ||