HashPivot

Pivot Array of Hash or Array of Struct or ActiveRecord::Relation.

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add hash_pivot

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install hash_pivot

Usage

Pivot Array of Hash

Prepare data

Prepare Array of Hash.

id	role	team	age
1	guest	rabbit	1
2	guest	mouse	2
3	guest	rabbit	3
4	admin	mouse	4

 data = [
  { id: 1, role: 'guest', team: 'rabbit', age: 1 },
  { id: 2, role: 'guest', team: 'mouse', age: 2 },
  { id: 3, role: 'guest', team: 'rabbit', age: 3 },
  { id: 4, role: 'admin', team: 'mouse', age: 4 }
]

Basic usage

Grouping by :role and pivot in :team. Pivot column is rabbit or mouse .

HashPivot.pivot(data, :role, :team, %w[rabbit mouse])

# [{ :role => "guest",
#    "rabbit" => [{ :id => 1, :role => "guest", :team => "rabbit", :age => 1 }, { :id => 3, :role => "guest", :team => "rabbit", :age => 3 }],
#    "mouse" => [{ :id => 2, :role => "guest", :team => "mouse", :age => 2 }] },
#  { :role => "admin", "rabbit" => [], "mouse" => [{ :id => 4, :role => "admin", :team => "mouse", :age => 4 }] }]

role	rabbit	mouse
guest	guest rabbit 1 guest rabbit 3	guest mouse 2
admin		admin mouse 4

Grouping by :role and pivot in :team.

Pivot column is nil. This means that pivot column is automatically configured.

HashPivot.pivot(data, :role, :team, nil)

# [{ :role => "guest",
#    "rabbit" => [{ :id => 1, :role => "guest", :team => "rabbit", :age => 1 }, { :id => 3, :role => "guest", :team => "rabbit", :age => 3 }],
#    "mouse" => [{ :id => 2, :role => "guest", :team => "mouse", :age => 2 }] },
#  { :role => "admin", "mouse" => [{ :id => 4, :role => "admin", :team => "mouse", :age => 4 }] }]

Pivot with summarize.

Pivot data is summarized by block.

Age is summarized by block.

HashPivot.pivot(data, :role, :team, %w[rabbit mouse]) { |array| array.sum { |h| h[:age] } }

# [{ :role => "guest", "rabbit" => 4, "mouse" => 2 }, { :role => "admin", "rabbit" => 0, "mouse" => 4 }]

role	rabbit	mouse
guest	4	2
admin	0	4

Pivot with summarize and replacing label.

If you give Hash for pivot kinds like this, pivot data is summarized by block and replace with labels.

pivot_kinds = { 'rabbit' => 'RABBIT AGE',
                'mouse' => 'MOUSE AGE' }

HashPivot.pivot(data, :role, :team, pivot_kinds) { |array| array.sum { |h| h[:age] } }

# [{ :role => "guest", "RABBIT AGE" => 4, "MOUSE AGE" => 2 }, { :role => "admin", "RABBIT AGE" => 0, "MOUSE AGE" => 4 }]

role	RABBIT AGE	MOUSE AGE
guest	4	2
admin	0	4

Pivot Array of Struct

Prepare data

Prepare Array of Struct.

HashPivotUserStruct = Struct.new(:id, :role, :team, :age, keyword_init: true)
data = [
  HashPivotUserStruct.new(id: 1, role: 'guest', team: 'rabbit', age: 1),
  HashPivotUserStruct.new(id: 2, role: 'guest', team: 'mouse', age: 2),
  HashPivotUserStruct.new({ id: 3, role: 'guest', team: 'rabbit', age: 3 }),
  HashPivotUserStruct.new({ id: 4, role: 'admin', team: 'mouse', age: 4 })
]

Basic usage

Grouping by :role and pivot in :team. Pivot column is rabbit or mouse .

HashPivot.pivot(data, :role, :team, %w[rabbit mouse], repository: HashPivot::Repository::StructRepository)

# [{ :role => "guest",
#    "rabbit" => [{ :id => 1, :role => "guest", :team => "rabbit", :age => 1 }, { :id => 3, :role => "guest", :team => "rabbit", :age => 3 }],
#    "mouse" => [{ :id => 2, :role => "guest", :team => "mouse", :age => 2 }] },
#  { :role => "admin", "rabbit" => [], "mouse" => [{ :id => 4, :role => "admin", :team => "mouse", :age => 4 }] }]

Pivot Array of ActiveRecord::Relation

Prepare data

Prepare Array of ActiveRecord::Relation.

class MigrateSqlDatabase < ActiveRecord::Migration[6.1]
  def self.up
    create_table(:hash_pivot_users) do |t|
      t.string :role
      t.string :team
      t.integer :age
    end
  end
end

HashPivotUser.destroy_all
HashPivotUser.create(:hash_pivot_user, id: 1, role: 'guest', team: 'rabbit', age: 1)
HashPivotUser.create(:hash_pivot_user, id: 2, role: 'guest', team: 'mouse', age: 2)
HashPivotUser.create(:hash_pivot_user, id: 3, role: 'guest', team: 'rabbit', age: 3)
HashPivotUser.create(:hash_pivot_user, id: 4, role: 'admin', team: 'mouse', age: 4)

Basic usage

Grouping by :role and pivot in :team. Pivot column is rabbit or mouse .

HashPivot.pivot(data, :role, :team, %w[rabbit mouse], repository: HashPivot::Repository::ActiveRecordRepository)

# [{ :role => "guest",
#    "rabbit" => [{ :id => 1, :role => "guest", :team => "rabbit", :age => 1 }, { :id => 3, :role => "guest", :team => "rabbit", :age => 3 }],
#    "mouse" => [{ :id => 2, :role => "guest", :team => "mouse", :age => 2 }] },
#  { :role => "admin", "rabbit" => [], "mouse" => [{ :id => 4, :role => "admin", :team => "mouse", :age => 4 }] }]

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/hash_pivot. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the HashPivot project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.