instance method `to_xml`

Ruby on Rails 4.2.9

Since v3.0.20

Available in: v3.0.20 v3.1.12 v3.2.22.5 v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

to_xml(options = {})

Returns a string containing an XML representation of its receiver:

{ foo: 1, bar: 2 }.to_xml
# =>
# <?xml version="1.0" encoding="UTF-8"?>
# <hash>
#   <foo type="integer">1</foo>
#   <bar type="integer">2</bar>
# </hash>

To do so, the method loops over the pairs and builds nodes that depend on the values. Given a pair key, value:

If value is a hash there’s a recursive call with key as :root.
If value is an array there’s a recursive call with key as :root, and key singularized as :children.
If value is a callable object it must expect one or two arguments. Depending on the arity, the callable is invoked with the options hash as first argument with key as :root, and key singularized as second argument. The callable can add nodes by using options[:builder].
```
'foo'.to_xml(lambda { |options, key| options[:builder].b(key) })
# => "<b>foo</b>"
```

If value responds to to_xml the method is invoked with key as :root.

class Foo
  def to_xml(options)
    options[:builder].bar 'fooing!'
  end
end

{ foo: Foo.new }.to_xml(skip_instruct: true)
# =>
# <hash>
#   <bar>fooing!</bar>
# </hash>

Otherwise, a node with key as tag is created with a string representation of value as text node. If value is nil an attribute “nil” set to “true” is added. Unless the option :skip_types exists and is true, an attribute “type” is added as well according to the following mapping:

XML_TYPE_NAMES = {
  "Symbol"     => "symbol",
  "Integer"    => "integer",
  "BigDecimal" => "decimal",
  "Float"      => "float",
  "TrueClass"  => "boolean",
  "FalseClass" => "boolean",
  "Date"       => "date",
  "DateTime"   => "dateTime",
  "Time"       => "dateTime"
}

By default the root node is “hash”, but that’s configurable via the :root option.

The default XML builder is a fresh instance of Builder::XmlMarkup. You can configure your own builder with the :builder option. The method also accepts options like :dasherize and friends, they are forwarded to the builder.

Parameters

options opt = {}

Source

# File activesupport/lib/active_support/core_ext/hash/conversions.rb, line 73
  def to_xml(options = {})
    require 'active_support/builder' unless defined?(Builder)

    options = options.dup
    options[:indent]  ||= 2
    options[:root]    ||= 'hash'
    options[:builder] ||= Builder::XmlMarkup.new(indent: options[:indent])

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

    root = ActiveSupport::XmlMini.rename_key(options[:root].to_s, options)

    builder.tag!(root) do
      each { |key, value| ActiveSupport::XmlMini.to_tag(key, value, options) }
      yield builder if block_given?
    end
  end

Defined in activesupport/lib/active_support/core_ext/hash/conversions.rb line 73 · View on GitHub · Improve this page · Find usages on GitHub

Defined in Hash

Signature

Parameters