| Module | ActiveRecord::Serialization |
| In: |
lib/active_record/serialization.rb
lib/active_record/serializers/json_serializer.rb lib/active_record/serializers/xml_serializer.rb |
Returns a JSON string representing the model. Some configuration is available through options.
Without any options, the returned JSON string will include all the model‘s attributes. For example:
konata = User.find(1)
konata.to_json
# => {"id": 1, "name": "Konata Izumi", "age": 16,
"created_at": "2006/08/01", "awesome": true}
The :only and :except options can be used to limit the attributes included, and work similar to the attributes method. For example:
konata.to_json(:only => [ :id, :name ])
# => {"id": 1, "name": "Konata Izumi"}
konata.to_json(:except => [ :id, :created_at, :age ])
# => {"name": "Konata Izumi", "awesome": true}
To include any methods on the model, use :methods.
konata.to_json(:methods => :permalink)
# => {"id": 1, "name": "Konata Izumi", "age": 16,
"created_at": "2006/08/01", "awesome": true,
"permalink": "1-konata-izumi"}
To include associations, use :include.
konata.to_json(:include => :posts)
# => {"id": 1, "name": "Konata Izumi", "age": 16,
"created_at": "2006/08/01", "awesome": true,
"posts": [{"id": 1, "author_id": 1, "title": "Welcome to the weblog"},
{"id": 2, author_id: 1, "title": "So I was thinking"}]}
2nd level and higher order associations work as well:
konata.to_json(:include => { :posts => {
:include => { :comments => {
:only => :body } },
:only => :title } })
# => {"id": 1, "name": "Konata Izumi", "age": 16,
"created_at": "2006/08/01", "awesome": true,
"posts": [{"comments": [{"body": "1st post!"}, {"body": "Second!"}],
"title": "Welcome to the weblog"},
{"comments": [{"body": "Don't think too hard"}],
"title": "So I was thinking"}]}
Builds an XML document to represent the model. Some configuration is available through options. However more complicated cases should override ActiveRecord::Base#to_xml.
By default the generated XML document will include the processing instruction and all the object‘s attributes. For example:
<?xml version="1.0" encoding="UTF-8"?>
<topic>
<title>The First Topic</title>
<author-name>David</author-name>
<id type="integer">1</id>
<approved type="boolean">false</approved>
<replies-count type="integer">0</replies-count>
<bonus-time type="datetime">2000-01-01T08:28:00+12:00</bonus-time>
<written-on type="datetime">2003-07-16T09:28:00+1200</written-on>
<content>Have a nice day</content>
<author-email-address>david@loudthinking.com</author-email-address>
<parent-id></parent-id>
<last-read type="date">2004-04-15</last-read>
</topic>
This behavior can be controlled with :only, :except, :skip_instruct, :skip_types and :dasherize. The :only and :except options are the same as for the attributes method. The default is to dasherize all column names, but you can disable this setting :dasherize to false. To not have the column type included in the XML output set :skip_types to true.
For instance:
topic.to_xml(:skip_instruct => true, :except => [ :id, :bonus_time, :written_on, :replies_count ])
<topic>
<title>The First Topic</title>
<author-name>David</author-name>
<approved type="boolean">false</approved>
<content>Have a nice day</content>
<author-email-address>david@loudthinking.com</author-email-address>
<parent-id></parent-id>
<last-read type="date">2004-04-15</last-read>
</topic>
To include first level associations use :include:
firm.to_xml :include => [ :account, :clients ]
<?xml version="1.0" encoding="UTF-8"?>
<firm>
<id type="integer">1</id>
<rating type="integer">1</rating>
<name>37signals</name>
<clients type="array">
<client>
<rating type="integer">1</rating>
<name>Summit</name>
</client>
<client>
<rating type="integer">1</rating>
<name>Microsoft</name>
</client>
</clients>
<account>
<id type="integer">1</id>
<credit-limit type="integer">50</credit-limit>
</account>
</firm>
To include deeper levels of associations pass a hash like this:
firm.to_xml :include => {:account => {}, :clients => {:include => :address}}
<?xml version="1.0" encoding="UTF-8"?>
<firm>
<id type="integer">1</id>
<rating type="integer">1</rating>
<name>37signals</name>
<clients type="array">
<client>
<rating type="integer">1</rating>
<name>Summit</name>
<address>
...
</address>
</client>
<client>
<rating type="integer">1</rating>
<name>Microsoft</name>
<address>
...
</address>
</client>
</clients>
<account>
<id type="integer">1</id>
<credit-limit type="integer">50</credit-limit>
</account>
</firm>
To include any methods on the model being called use :methods:
firm.to_xml :methods => [ :calculated_earnings, :real_earnings ]
<firm>
# ... normal attributes as shown above ...
<calculated-earnings>100000000000000000</calculated-earnings>
<real-earnings>5</real-earnings>
</firm>
To call any additional Procs use :procs. The Procs are passed a modified version of the options hash that was given to to_xml:
proc = Proc.new { |options| options[:builder].tag!('abc', 'def') }
firm.to_xml :procs => [ proc ]
<firm>
# ... normal attributes as shown above ...
<abc>def</abc>
</firm>
Alternatively, you can yield the builder object as part of the to_xml call:
firm.to_xml do |xml|
xml.creator do
xml.first_name "David"
xml.last_name "Heinemeier Hansson"
end
end
<firm>
# ... normal attributes as shown above ...
<creator>
<first_name>David</first_name>
<last_name>Heinemeier Hansson</last_name>
</creator>
</firm>
As noted above, you may override to_xml in your ActiveRecord::Base subclasses to have complete control about what‘s generated. The general form of doing this is:
class IHaveMyOwnXML < ActiveRecord::Base
def to_xml(options = {})
options[:indent] ||= 2
xml = options[:builder] ||= Builder::XmlMarkup.new(:indent => options[:indent])
xml.instruct! unless options[:skip_instruct]
xml.level_one do
xml.tag!(:second_level, 'content')
end
end
end