Module: ActiveSupport::DeepMergeable

Included in:
ActionController::Parameters, Hash
Defined in:
activesupport/lib/active_support/deep_mergeable.rb

Overview

Provides deep_merge and deep_merge! methods. Expects the including class to provide a merge!(other, &block) method.

Instance Method Summary collapse

Instance Method Details

#deep_merge(other, &block) ⇒ Object

Returns a new instance with the values from other merged recursively.

class Hash
  include ActiveSupport::DeepMergeable
end

hash_1 = { a: true, b: { c: [1, 2, 3] } }
hash_2 = { a: false, b: { x: [3, 4, 5] } }

hash_1.deep_merge(hash_2)
# => { a: false, b: { c: [1, 2, 3], x: [3, 4, 5] } }

A block can be provided to merge non-DeepMergeable values:

hash_1 = { a: 100, b: 200, c: { c1: 100 } }
hash_2 = { b: 250, c: { c1: 200 } }

hash_1.deep_merge(hash_2) do |key, this_val, other_val|
  this_val + other_val
end
# => { a: 100, b: 450, c: { c1: 300 } }



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# File 'activesupport/lib/active_support/deep_mergeable.rb', line 29

def deep_merge(other, &block)
  dup.deep_merge!(other, &block)
end

#deep_merge!(other, &block) ⇒ Object

Same as #deep_merge, but modifies self.



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# File 'activesupport/lib/active_support/deep_mergeable.rb', line 34

def deep_merge!(other, &block)
  merge!(other) do |key, this_val, other_val|
    if this_val.is_a?(DeepMergeable) && this_val.deep_merge?(other_val)
      this_val.deep_merge(other_val, &block)
    elsif block_given?
      block.call(key, this_val, other_val)
    else
      other_val
    end
  end
end

#deep_merge?(other) ⇒ Boolean

Returns true if other can be deep merged into self. Classes may override this method to restrict or expand the domain of deep mergeable values. Defaults to checking that other is of type self.class.

Returns:

  • (Boolean) 


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# File 'activesupport/lib/active_support/deep_mergeable.rb', line 49

def deep_merge?(other)
  other.is_a?(self.class)
end