activeadmin_calendar

Adds index as: :calendar to ActiveAdmin — renders the resource list as a month grid with one cell per day. The index block is yielded (date, records_for_that_day).

Works with ActiveAdmin 3.5+ and 4.x.

ActiveAdmin 4

ActiveAdmin 3

Install

# Gemfile
gem "activeadmin_calendar"

For Sprockets (AA 3):

/* app/assets/stylesheets/active_admin.scss */
@import "activeadmin_calendar";

Propshaft / Tailwind (AA 4) picks the bundled CSS up automatically.

Usage

Single-date events — `group_by:`

One SQL query per visible month, rows bucketed in Ruby.

ActiveAdmin.register Payment do
  config.paginate = false
  filter :card_type, as: :select, collection: Payment::CARD_TYPES

  index as: :calendar, group_by: :paid_at do |date, payments|
    by_card = payments.group_by(&:card_type)
                      .transform_values { |ps| ps.sum(&:amount) }
    ul do
      by_card.each { |c, sum| li "#{c.upcase}: #{number_to_currency(sum)}" }
      total = by_card.values.sum
      li { strong "Total: #{number_to_currency(total)}" } unless total.zero?
    end
  end
end

Range / fan-out events — `group_by_scope:`

One row appears in every day in its active range. Use a custom scope:

ActiveAdmin 4

ActiveAdmin 3

class Booking < ApplicationRecord
  scope :active_on, ->(date) { where("check_in <= ? AND check_out > ?", date, date) }
end

ActiveAdmin.register Booking do
  filter :room_number
  filter :guest_name_cont, label: "Guest name contains"

  index as: :calendar, group_by_scope: :active_on do |date, bookings|
    ul do
      bookings.sort_by(&:room_number).each do |b|
        first, last = b.check_in == date, b.check_out - 1.day == date
        marker = first && last ? "•" : first ? "→" : last ? "←" : "·"
        li { text_node "#{marker} ##{b.room_number} #{b.guest_name}" }
      end
    end
  end
end

May 18 → 21 booking shows on 18 (→), 19 (·), 20 (←).

Options

Option	Effect
`group_by:` (Symbol)	Bucket by a date/datetime column. 1 SQL per month (prefetched).
`group_by_scope:` (Symbol)	Call `Model.scope(date)` per cell — for ranges, joins, or any bucket logic that simple `where(col = date)` can't express. N SQL per month (one per visible day).

URL params ?year=2026&month=5 drive the visible month. Today / Previous / Next links are rendered automatically and preserve current filter params.

Ransack filters apply transparently — the gem buckets the already-scoped collection. ?q[card_type_eq]=visa narrows what's shown in each cell.

Compatibility

AA	Status
4.0.0.beta22	✅
3.5	✅

License

MIT