Class: Hash

Inherits:
Object show all
Defined in:
lib/to-javascript/encoders/hash.rb

Instance Method Summary collapse

Instance Method Details

#to_js(options = {}) ⇒ Object

Returns a Javascript string representing the hash.

Just like to_json, without any options, the returned javascript equivalent the obejct For example:

{ :name => "Konata Izumi", 'age' => 16, 1 => 2 }.to_js
# => {"name": "Konata Izumi", 1: 2, "age": 16}

The keys in the javascript string are unordered due to the nature of hashes.

Also like to_jason, the :only and :except options can be used to limit the attributes included, and will accept 1 or more hash keys to include/exclude.

{ :name => "Konata Izumi", 'age' => 16, 1 => 2 }.to_js(:only => [:name, 'age'])
# => {"name": "Konata Izumi", "age": 16}

{ :name => "Konata Izumi", 'age' => 16, 1 => 2 }.to_js(:except => 1)
# => {"name": "Konata Izumi", "age": 16}

The options also filter down to any hash values. This is particularly useful for converting hashes containing ActiveRecord objects or any object that responds to options in their to_js method. For example:

users = User.find(:all)
{ :users => users, :count => users.size }.to_js(:include => :posts)

would pass the :include => :posts option to users, allowing the posts association in the User model to be converted to javascript as well.



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# File 'lib/to-javascript/encoders/hash.rb', line 31

def to_js(options = {})
  hash_keys = self.keys

  if options[:except]
    hash_keys = hash_keys - Array(options[:except])
  elsif options[:only]
    hash_keys = hash_keys & Array(options[:only])
  end

  returning result = ActiveSupport::JS::Code.new('{') do
    result << hash_keys.map do |key|
      "#{ActiveSupport::JS.encode(key)}: #{ActiveSupport::JS.encode(self[key], options)}"
    end * ', '
    result << '}'
  end
  
end