Module ActiveSupport::CoreExtensions::Array::Conversions
In: vendor/rails/activesupport/lib/active_support/core_ext/array/conversions.rb

Methods

Public Instance methods

Converts a collection of elements into a formatted string by calling to_s on all elements and joining them:

  Blog.find(:all).to_formatted_s # => "First PostSecond PostThird Post"

Adding in the :db argument as the format yields a prettier output:

  Blog.find(:all).to_formatted_s(:db) # => "First Post,Second Post,Third Post"

[Source]

    # File vendor/rails/activesupport/lib/active_support/core_ext/array/conversions.rb, line 57
57:         def to_formatted_s(format = :default)
58:           case format
59:             when :db
60:               if respond_to?(:empty?) && self.empty?
61:                 "null"
62:               else
63:                 collect { |element| element.id }.join(",")
64:               end
65:             else
66:               to_default_s
67:           end
68:         end

Calls to_param on all its elements and joins the result with slashes. This is used by url_for in Action Pack.

[Source]

    # File vendor/rails/activesupport/lib/active_support/core_ext/array/conversions.rb, line 29
29:         def to_param
30:           map(&:to_param).join '/'
31:         end

Converts an array into a string suitable for use as a URL query string, using the given key as the param name.

  ['Rails', 'coding'].to_query('hobbies') # => "hobbies%5B%5D=Rails&hobbies%5B%5D=coding"

[Source]

    # File vendor/rails/activesupport/lib/active_support/core_ext/array/conversions.rb, line 37
37:         def to_query(key)
38:           collect { |value| value.to_query("#{key}[]") } * '&'
39:         end

Converts the array to a comma-separated sentence where the last element is joined by the connector word. Options:

  • :connector - The word used to join the last element in arrays with two or more elements (default: "and")
  • :skip_last_comma - Set to true to return "a, b and c" instead of "a, b, and c".

[Source]

    # File vendor/rails/activesupport/lib/active_support/core_ext/array/conversions.rb, line 10
10:         def to_sentence(options = {})
11:           options.assert_valid_keys(:connector, :skip_last_comma)
12:           options.reverse_merge! :connector => 'and', :skip_last_comma => false
13:           options[:connector] = "#{options[:connector]} " unless options[:connector].nil? || options[:connector].strip == ''
14: 
15:           case length
16:             when 0
17:               ""
18:             when 1
19:               self[0].to_s
20:             when 2
21:               "#{self[0]} #{options[:connector]}#{self[1]}"
22:             else
23:               "#{self[0...-1].join(', ')}#{options[:skip_last_comma] ? '' : ','} #{options[:connector]}#{self[-1]}"
24:           end
25:         end

Returns a string that represents this array in XML by sending to_xml to each element. Active Record collections delegate their representation in XML to this method.

All elements are expected to respond to to_xml, if any of them does not an exception is raised.

The root node reflects the class name of the first element in plural if all elements belong to the same type and that‘s not Hash:

  customer.projects.to_xml

  <?xml version="1.0" encoding="UTF-8"?>
  <projects type="array">
    <project>
      <amount type="decimal">20000.0</amount>
      <customer-id type="integer">1567</customer-id>
      <deal-date type="date">2008-04-09</deal-date>
      ...
    </project>
    <project>
      <amount type="decimal">57230.0</amount>
      <customer-id type="integer">1567</customer-id>
      <deal-date type="date">2008-04-15</deal-date>
      ...
    </project>
  </projects>

Otherwise the root element is "records":

  [{:foo => 1, :bar => 2}, {:baz => 3}].to_xml

  <?xml version="1.0" encoding="UTF-8"?>
  <records type="array">
    <record>
      <bar type="integer">2</bar>
      <foo type="integer">1</foo>
    </record>
    <record>
      <baz type="integer">3</baz>
    </record>
  </records>

If the collection is empty the root element is "nil-classes" by default:

  [].to_xml

  <?xml version="1.0" encoding="UTF-8"?>
  <nil-classes type="array"/>

To ensure a meaningful root element use the :root option:

  customer_with_no_projects.projects.to_xml(:root => "projects")

  <?xml version="1.0" encoding="UTF-8"?>
  <projects type="array"/>

By default root children have as node name the one of the root singularized. You can change it with the :children option.

The options hash is passed downwards:

  Message.all.to_xml(:skip_types => true)

  <?xml version="1.0" encoding="UTF-8"?>
  <messages>
    <message>
      <created-at>2008-03-07T09:58:18+01:00</created-at>
      <id>1</id>
      <name>1</name>
      <updated-at>2008-03-07T09:58:18+01:00</updated-at>
      <user-id>1</user-id>
    </message>
  </messages>

[Source]

     # File vendor/rails/activesupport/lib/active_support/core_ext/array/conversions.rb, line 145
145:         def to_xml(options = {})
146:           raise "Not all elements respond to to_xml" unless all? { |e| e.respond_to? :to_xml }
147: 
148:           options[:root]     ||= all? { |e| e.is_a?(first.class) && first.class.to_s != "Hash" } ? first.class.to_s.underscore.pluralize : "records"
149:           options[:children] ||= options[:root].singularize
150:           options[:indent]   ||= 2
151:           options[:builder]  ||= Builder::XmlMarkup.new(:indent => options[:indent])
152: 
153:           root     = options.delete(:root).to_s
154:           children = options.delete(:children)
155: 
156:           if !options.has_key?(:dasherize) || options[:dasherize]
157:             root = root.dasherize
158:           end
159: 
160:           options[:builder].instruct! unless options.delete(:skip_instruct)
161: 
162:           opts = options.merge({ :root => children })
163: 
164:           xml = options[:builder]
165:           if empty?
166:             xml.tag!(root, options[:skip_types] ? {} : {:type => "array"})
167:           else
168:             xml.tag!(root, options[:skip_types] ? {} : {:type => "array"}) {
169:               yield xml if block_given?
170:               each { |e| e.to_xml(opts.merge!({ :skip_instruct => true })) }
171:             }
172:           end
173:         end

[Validate]