GroupsBy

Installation

Add this line to your application's Gemfile:

gem 'groups_by'

And then execute:

$ bundle

Or install it yourself as:

$ gem install groups_by

Usage

There are several ways of using groups_by.

Base

The first way is to go through the GroupsBy class itself.

    require 'groups_by'

    # @param source [Array<Hash>]
    # @option [Array<String,Symbol,Proc>] :group_by_rules
    # @option [Proc] :summarizer
    GroupsBy.new.groups_by(
            source,
            group_by_rules: grouping_rules,
            summarizer: summarizer)

CoreExt

The second way is to modify the Array class by including core extension.

    require 'groups_by/core_ext/array'   # extends only Array

    data = [
      { value1: 10, value2: 100, name: 'Stanton',  company: 'Smith Inc', id: '-one-' },
      { value1: 20, value2: 200, name: 'Stanton',  company: 'Fisher LLC', id: '-three-' },
      { value1: 50, value2: 500, name: 'Darrel', company: 'Smith Inc', id: '-three-' }
    ]

    result = data.groups_by(:name, :company, ->(el) { el[:id][/\w+/]})
    # => {"Stanton"=>{"Smith Inc"=>{"one"=>[{:value1=>10, :value2=>100, :name=>"Stanton", :company=>"Smith Inc", :id=>"-one-"}]}, "Fisher LLC"=>{"three"=>[{:value1=>20, :value2=>200, :name=>"Stanton", :company=>"Fisher LLC", :id=>"-three-"}]}}, "Darrel"=>{"Smith Inc"=>{"three"=>[{:value1=>50, :value2=>500, :name=>"Darrel", :company=>"Smith Inc", :id=>"-three-"}]}}}

    GroupsBy.pritify result
    # =>
    #   Stanton
	#   	Smith Inc
	#   		one
	#   			value1    value2    name      company   id
	#   			10        100       Stanton   Smith Inc -one-
	#   	Fisher LLC
	#   		three
	#   			value1     value2     name       company    id
	#   			20         200        Stanton    Fisher LLC -three-
	#   Darrel
	#   	Smith Inc
	#   		three
	#   			value1    value2    name      company   id
	#   			50        500       Darrel    Smith Inc -three-      

Summarizer

You can pass summarize logic into grouper to summarize desirable values

    data = [
      { value1: 10, value2: 100, name: 'Stanton',  company: 'Smith Inc', id: '-one-' },
      { value1: 20, value2: 200, name: 'Stanton',  company: 'Fisher LLC', id: '-three-' },
      { value1: 50, value2: 500, name: 'Darrel', company: 'Smith Inc', id: '-three-' }
    ]

    grouping_rules = [:name, :company, ->(el) { el[:id][/\w+/]}]

    summarizer = lambda do |elements|
      {
        value1_sum: elements.map { |m| m[:value1].to_f }.reduce(&:+),
        value2_sum: elements.map { |m| m[:value2].to_f }.reduce(&:+)
      }
    end

    result = GroupsBy.new.groups_by(
            data,
            group_by_rules: grouping_rules,
            summarizer: summarizer)      
    # => {"Stanton"=>{"Smith Inc"=>{"one"=>{:values=>[{:value1=>10, :value2=>100, :name=>"Stanton", :company=>"Smith Inc", :id=>"-one-"}]}, :totals=>{:value1_sum=>10.0, :value2_sum=>100.0}}, "Fisher LLC"=>{"three"=>{:values=>[{:value1=>20, :value2=>200, :name=>"Stanton", :company=>"Fisher LLC", :id=>"-three-"}]}, :totals=>{:value1_sum=>20.0, :value2_sum=>200.0}}, :totals=>{:value1_sum=>30.0, :value2_sum=>300.0}}, "Darrel"=>{"Smith Inc"=>{"three"=>{:values=>[{:value1=>50, :value2=>500, :name=>"Darrel", :company=>"Smith Inc", :id=>"-three-"}]}, :totals=>{:value1_sum=>50.0, :value2_sum=>500.0}}, :totals=>{:value1_sum=>50.0, :value2_sum=>500.0}}, :totals=>{:value1_sum=>80.0, :value2_sum=>800.0}}

    GroupsBy.pritify result
    # =>
    # Stanton
  	# 	Smith Inc
  	# 		one
  	# 			value1    value2    name      company   id
  	# 			10        100       Stanton   Smith Inc -one-
  	# 		value1_sum value2_sum
  	# 		10.0       100.0
  	# 	Fisher LLC
  	# 		three
  	# 			value1     value2     name       company    id
  	# 			20         200        Stanton    Fisher LLC -three-
  	# 		value1_sum value2_sum
  	# 		20.0       200.0
  	# 	value1_sum value2_sum
  	# 	30.0       300.0
  	# Darrel
  	# 	Smith Inc
  	# 		three
  	# 			value1    value2    name      company   id
  	# 			50        500       Darrel    Smith Inc -three-
  	# 		value1_sum value2_sum
  	# 		50.0       500.0
  	# 	value1_sum value2_sum
  	# 	50.0       500.0
  	# value1_sum value2_sum
  	# 80.0       800.0     

Pritify

Display grouped array in prettified way

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.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/karol-blaszczyk/groups_by. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant 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 GroupsBy project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.