Module: ActiveSupport::CoreExtensions::Array::Conversions

Included in:
Array
Defined in:
lib/active_support/core_ext/array/conversions.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object

:nodoc:


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# File 'lib/active_support/core_ext/array/conversions.rb', line 41

def self.included(base) #:nodoc:
  base.class_eval do
    alias_method :to_default_s, :to_s
    alias_method :to_s, :to_formatted_s
  end
end

Instance Method Details

#to_formatted_s(format = :default) ⇒ Object

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"

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# File 'lib/active_support/core_ext/array/conversions.rb', line 57

def to_formatted_s(format = :default)
  case format
    when :db
      if respond_to?(:empty?) && self.empty?
        "null"
      else
        collect { |element| element.id }.join(",")
      end
    else
      to_default_s
  end
end

#to_paramObject

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


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# File 'lib/active_support/core_ext/array/conversions.rb', line 29

def to_param
  map(&:to_param).join '/'
end

#to_query(key) ⇒ Object

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"

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# File 'lib/active_support/core_ext/array/conversions.rb', line 37

def to_query(key)
  collect { |value| value.to_query("#{key}[]") } * '&'
end

#to_sentence(options = {}) ⇒ Object

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”.


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# File 'lib/active_support/core_ext/array/conversions.rb', line 10

def to_sentence(options = {})
  options.assert_valid_keys(:connector, :skip_last_comma)
  options.reverse_merge! :connector => 'and', :skip_last_comma => false
  options[:connector] = "#{options[:connector]} " unless options[:connector].nil? || options[:connector].strip == ''

  case length
    when 0
      ""
    when 1
      self[0].to_s
    when 2
      "#{self[0]} #{options[:connector]}#{self[1]}"
    else
      "#{self[0...-1].join(', ')}#{options[:skip_last_comma] ? '' : ','} #{options[:connector]}#{self[-1]}"
  end
end

#to_xml(options = {}) ⇒ Object

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>

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# File 'lib/active_support/core_ext/array/conversions.rb', line 145

def to_xml(options = {})
  raise "Not all elements respond to to_xml" unless all? { |e| e.respond_to? :to_xml }

  options[:root]     ||= all? { |e| e.is_a?(first.class) && first.class.to_s != "Hash" } ? first.class.to_s.underscore.pluralize : "records"
  options[:children] ||= options[:root].singularize
  options[:indent]   ||= 2
  options[:builder]  ||= Builder::XmlMarkup.new(:indent => options[:indent])

  root     = options.delete(:root).to_s
  children = options.delete(:children)

  if !options.has_key?(:dasherize) || options[:dasherize]
    root = root.dasherize
  end

  options[:builder].instruct! unless options.delete(:skip_instruct)

  opts = options.merge({ :root => children })

  xml = options[:builder]
  if empty?
    xml.tag!(root, options[:skip_types] ? {} : {:type => "array"})
  else
    xml.tag!(root, options[:skip_types] ? {} : {:type => "array"}) {
      yield xml if block_given?
      each { |e| e.to_xml(opts.merge!({ :skip_instruct => true })) }
    }
  end
end