If you'd like to add rows or columns that aggregate the table's data, you can use report_options.aggregations. Currently, the only supported operator is sum, but others may be supported in the future.

For example, if you want to add a row at the bottom of a table that shows the sum of each column and a column at the end of the table that shows the sum of each row, use the following:

report_options:
  aggregations:
    - from: columns
      operator: sum
      label: Total
    - from: rows
      operator: sum
      label: Total

To create the chart above, simply add the following YAML file and call render_report in any view:

YAML

config/reports_kit/reports/table_with_aggregations.yml

measure: post
filters:
- key: author
- key: created_at
  criteria:
    operator: between
    value: "-3M - now"
dimensions:
- key: tags
  label: Tag
- key: author
  limit: 5
order: dimension1.label
format: table
report_options:
  aggregations:
  - from: columns
    operator: sum
    label: Total
  - from: rows
    operator: sum
    label: Total

View

app/views/my_controller/my_view.html.haml

= render_report 'table_with_aggregations' do |report|
  = report.form do |f|
    .pull-right
      = f.date_range :created_at
    = f.multi_autocomplete :author, placeholder: 'Author...'

Model

app/models/post.rb

class Post < ApplicationRecord
  belongs_to :author
  has_many :post_views, dependent: :destroy
  has_many :posts_tags, dependent: :destroy
  has_many :tags, through: :posts_tags

  include ReportsKit::Model
  reports_kit do
    aggregation :average_time_to_publish, [:average, 'posts.published_at - posts.created_at']
    contextual_filter :for_author, ->(relation, context_params) { relation.where(author_id: context_params[:author_id]) }
    dimension :approximate_views_count, group: 'ROUND(posts.views_count, -1)'
    filter :is_published, :boolean, conditions: ->(relation) { relation.where(status: 'published') }
  end

  STATUSES = %w(draft private published).freeze

  def to_s
    title
  end
end

Model's Columns

id              integer
author_id       integer
title           string
status          string
published_at    datetime
is_featured     boolean
views_count     integer
created_at      datetime
updated_at      datetime