CrazyHashFilter

Hash filtering by advanced rules.

Can be used to reduce API data throughput if you are building API responses from hashes.

Installation

Add this line to your application's Gemfile:

gem 'crazy_hash_filter'

Usage

You can use hash filter like this:

  filtered_hash = CrazyHashFilter.process(hash, rules)

Or shorthand versions:

  filtered_hash = hash.crazy_filter(rules)

Filtering in place:

  hash.crazy_filter!(rules)

Sample hash

  @sample = {
    :code => 0,
    :items => [
      { :id => 1,
        :title => 'First item',
        :thumbs => [
          { :code => '50', :url => 'http://some-url/1/50' },
          { :code => '100', :url => 'http://some-url/1/100' },
          { :code => '150', :url => 'http://some-url/1/150' }
        ]
      },
      { :id => 2,
        :title => 'Second item',
        :thumbs => [
          { :code => '50', :url => 'http://some-url/2/50' },
          { :code => '100', :url => 'http://some-url/2/100' },
          { :code => '150', :url => 'http://some-url/2/150' }
        ]
      },
    ]
  }

Simple filtering

  rules  = { :select => [ :code ] }

Result

  result = CrazyHashFilter.process(@sample, rules)

  { :code => 0 }

Filtering with nested rules

  rules = {
    :select => [ :code, :items ],
    :child_rules => {
      :items => { :select => [ :id, :title ] }
    }
  }

Result

  result = CrazyHashFilter.process(@sample, rules)

  { :code=>0,
    :items=> [
      {:id=>1, :title=>"First item"},
      {:id=>2, :title=>"Second item"}
    ]
  }

Filtering with conditions

  rules = {
    :select => [ :code, :items ],
      :child_rules => {
      :items => {
        :select => [ :id, :thumbs ],

        :child_rules => {
          :thumbs => {
            :conditions => {
              :code => '50'
            }
          }
        }
      }
    }
  }

Result

  result = CrazyHashFilter.process(@sample, rules)

  { :code=>0,
    :items=> [
      { :id=>1, :thumbs=> [ { :code=>"50", :url=> "http://some-url/1/50" } ] },
      { :id=>2, :thumbs=> [ { :code=>"50", :url=> "http://some-url/2/50" } ] }
  ]}

Filtering with conditions array

  rules = {
    :select => [ :code, :items ],
      :child_rules => {
      :items => {
        :select => [ :id, :thumbs ],

        :child_rules => {
          :thumbs => {
            :conditions => {
              :code => [ '50', '100' ]
            }
          }
        }
      }
    }
  }

Result

  result = CrazyHashFilter.process(@sample, rules)

  { :code => 0,
    :items=> [
      { :id=>1,
        :thumbs=>[
          { :code => "50", :url => "http://some-url/1/50" },
          { :code => "100", :url => "http://some-url/1/100" }
        ]
      },
      { :id => 2,
        :thumbs => [
          { :code => "50", :url => "http://some-url/2/50" },
          { :code => "100", :url => "http://some-url/2/100" }
        ]
      }
    ]
  }