Module: Institutions::Merge

Included in:
Institution
Defined in:
lib/institutions/institution/merge.rb

Overview

:no_doc

Instance Method Summary collapse

Instance Method Details

#merge(arg = {}) ⇒ Object

Merges the given arguments into the Institution. Internally uses a “recursive merge” algorithm to preserve as much of the original Institution as possible. Assumes the argument has a to_hash method Example.

require 'institutions'
hash1 = { "string_attribute" => "first string",
          :nested_hash_attribute => {
            :h1 => {:h1_2 => "first12"},
            :h2 => {:h2_1 => "first21", :h2_2 => "first22"}},
          :array_attribute => [1, 2, 4] }
institution1 = Institutions::Institution.new("first_inst", "First Institution", hash1)
p institution1        # -> #<Institutions::Institution @code=:first_inst, @name="First Institution", @array_attribute=[1, 2, 4], @default=false, @string_attribute="first string", @nested_hash_attribute={:h1=>{:h1_2=>"first12"}, :h2=>{:h2_1=>"first21", :h2_2=>"first22"}}>
hash2 = { "string_attribute" => "second string",
          :nested_hash_attribute => {:h1 => {
            :h1_2 => "second12"},
            :h2 => {:h2_2 => "second22"}},
          :array_attribute => [1, 2, 3], :default => true }
institution2 = Institutions::Institution.new("second_inst", "Second Institution", hash2)
p institution2        # -> <Institutions::Institution @code=:second_inst, @name="Second Institution", @array_attribute=[1, 2, 3], @default=true, @string_attribute="second string", @nested_hash_attribute={:h1=>{:h1_2=>"second12"}, :h2=>{:h2_2=>"second22"}}>
institution1.merge(institution2)
p institution1        # -> #<Institutions::Institution @code=:first_inst, @name="First Institution", @array_attribute=[1, 2, 4, 3], @default=true, @string_attribute="second string", @nested_hash_attribute={:h1=>{:h1_2=>"second12"}, :h2=>{:h2_1=>"first21", :h2_2=>"second22"}}>



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# File 'lib/institutions/institution/merge.rb', line 28

def merge(arg={})
  arg.to_hash.each do |key, value|
    next unless valid_instance_variable? key
    instance_variable = instance_variablize(key)
    if instance_variable_defined? instance_variable
      instance_variable_set(instance_variable, deep_merge(instance_variable_get(instance_variable), value, key))
    else
      writer_method = "#{key}=".to_sym
      if respond_to? writer_method
        send writer_method, value
      else
        next if [:code, :name].include? key.to_sym
        # Set each hash value as an instance variable, but don't overwrite code or name values.
        instance_variable_set(instance_variable, value)
      end
    end
  end
end