Module ActiveSupport::CoreExtensions::Hash::Slice
In: vendor/rails/activesupport/lib/active_support/core_ext/hash/slice.rb

Slice a hash to include only the given keys. This is useful for limiting an options hash to valid keys before passing to a method:

  def search(criteria = {})
    assert_valid_keys(:mass, :velocity, :time)
  end

  search(options.slice(:mass, :velocity, :time))

If you have an array of keys you want to limit to, you should splat them:

  valid_keys = [:mass, :velocity, :time]
  search(options.slice(*valid_keys))

Methods

slice   slice!  

Public Instance methods

Returns a new hash with only the given keys.

[Source]

    # File vendor/rails/activesupport/lib/active_support/core_ext/hash/slice.rb, line 19
19:         def slice(*keys)
20:           keys = keys.map! { |key| convert_key(key) } if respond_to?(:convert_key)
21:           hash = self.class.new
22:           keys.each { |k| hash[k] = self[k] if has_key?(k) }
23:           hash
24:         end

Replaces the hash with only the given keys.

[Source]

    # File vendor/rails/activesupport/lib/active_support/core_ext/hash/slice.rb, line 27
27:         def slice!(*keys)
28:           replace(slice(*keys))
29:         end

[Validate]