Our Rails application needs to support both xml and json formats. In
some cases, we need to return custom XML that spans several objects
and associations. I've been able to write custom to_xml methods that
use the builder and block functionality. When trying the same thing
with the to_json method, I failed to get the same result.
Basically to_xml has this signature: to_xml(options = {}, &block).
I've perused around and it appears to_json has this signature:
to_json(options = {}). Is there a version of to_json that will yield
to a block
and provide the json builder? Can someone please tell me if I've done
something wrong with the code below? Is there is a plugin or newer
version of Rails that will add the same support for to_json that
to_xml supports?
Here is the relevant code
class Conference < ActiveRecord::Base
has_many :courses, :dependent => :destroy
end
class Course < ActiveRecord::Base
belongs_to :conference
has_many :sessions, :dependent => :destroy
has_one :manual
# just a place holder method so we can serialize it
def pre_requisite
"An open mind"
end
end
class Session < ActiveRecord::Base
belongs_to :courses
has_one :presentation, :dependent=>:destroy
# just a place holder method so we can serialize it
def maximum_capacity_reached?
false;
end
end
class Presentation < ActiveRecord::Base
belongs_to :session
belongs_to :instructor
end
class Manual < ActiveRecord::Base
belongs_to :course
end
class Instructor < ActiveRecord::Base
end
Now let's suppose I have a controller that will return the full detail
of a conference and needs all of the related data and will also
serialize some custom methods.
class ConferencesController < ApplicationController
# GET /conferences/:id
def show
conference_id = params[:id]
respond_to do |format|
format.html # unsupported
format.json {
render(:json=>Conference.full_json(conference_id))
}
format.xml {
render(:xml=>Conference.full_xml(conference_id))
}
end
end
end
So I've extended the conference class so that it can build this nested
xml along with the result of selective methods on various classes.
this code uses the fact that to_xml has this signature: to_xml(options
= {}, &block)
class Conference < ActiveRecord::Base
has_many :courses, :dependent => :destroy
def slogan
"#{name}: Be here or be in the dark!"
end
def self.full_xml(conference_id)
# ensure we've loaded the full structure in the most efficient
manner
conference = Conference.find(conference_id, :include=>{:courses
=>
[:manual, {:sessions=>:presentation}]})
# extract detailed hierarchical xml
conference.to_xml do |xml|
xml.slogan conference.slogan # output the banner
#iterate courses and any custom methods
xml.courses{
conference.courses.each do |course|
course.to_xml(:builder=>xml,
:skip_instruct => true) do |
xml_course|
xml_course.sessions{
#iterate sessions and
any custom methods
course.sessions.each do
|session|
session.to_xml(:builder=>xml_course, :skip_instruct => true)
do |xml_course_session|
xml_course_session.is_at_capacity
session.maximum_capacity_reached?
end
end
}
end
end
}
end
end
def self.full_json(conference_id)
# ensure we've loaded the full structure in the most efficient
manner
conference = Conference.find(conference_id, :include=>{:courses
=>
[:manual, {:sessions=>:presentation}]})
debugger()
# extract detailed hierarchical xml
conference.to_json do |json|
json.slogan conference.slogan # output the banner
#iterate courses and any custom methods
json.courses{
conference.courses.each do |course|
course.to_json(:builder=>json,
:skip_instruct => true) do |
json_course|
json_course.sessions{
#iterate sessions and
any custom methods
course.sessions.each do
|session|
session.to_json(:builder=>json_course, :skip_instruct => true)
do |json_course_session|
json_course_session.is_at_capacity
session.maximum_capacity_reached?
end
end
}
end
end
}
end
end
end
When I invoke the method, via http://localhost:3000/conferences/1.xml,
I get the desired generated XML output:
<conference>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<id type="integer">1</id>
<name>Ruby Live</name>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<slogan>Ruby Live: Be here or be in the dark!</slogan>
-
<courses>
-
<course>
<conference-id type="integer">1</conference-id>
<course-name>Action Controller: In Depth</course-name>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<id type="integer">1</id>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
-
<sessions>
-
<session>
<course-id type="integer">1</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-04T15:59:41-08:00</end-time>
<id type="integer">1</id>
<rating type="integer">4</rating>
<room-number>101</room-number>
<start-time type="datetime">2008-12-04T13:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
-
<session>
<course-id type="integer">1</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-05T15:59:41-08:00</end-time>
<id type="integer">2</id>
<rating type="integer">4</rating>
<room-number>101</room-number>
<start-time type="datetime">2008-12-05T13:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
</sessions>
</course>
+
<course>
<conference-id type="integer">1</conference-id>
<course-name>Active Record: In Depth</course-name>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<id type="integer">2</id>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
-
<sessions>
-
<session>
<course-id type="integer">2</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-04T17:59:41-08:00</end-time>
<id type="integer">3</id>
<rating type="integer">5</rating>
<room-number>201</room-number>
<start-time type="datetime">2008-12-04T15:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
-
<session>
<course-id type="integer">2</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-05T17:59:41-08:00</end-time>
<id type="integer">4</id>
<rating type="integer">5</rating>
<room-number>201</room-number>
<start-time type="datetime">2008-12-05T15:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
</sessions>
</course>
</courses>
</conference>
When I invoke the method, via http://localhost:3000/conferences/1.json,
I get the following undesired generated json output. Basically the
builder and block that acts on to_xml is ignored or defunct.
{"name": "Ruby Live", "updated_at": "2008/11/04 13:59:41 -0800", "id":
1, "created_at": "2008/11/04 13:59:41 -0800"}
I need to support both xml and json formats while returning the same
data. Can someone please tell me what if there is a plugin or newer
version of Rails that will add this same support for to_json that
to_xml supports?Our application needs to support both xml and json
formats while returning the same data. In some cases, we need to
return custom XML that spans several objects and associations. I've
been able to write custom to_xml methods that use the builder and
block functionality. When trying the same thing with the to_json
method, I failed to get the same result. Can someone please tell me
if I've done something wrong with the code below? Is there is a
plugin or newer version of Rails that will add the
same support for to_json that to_xml supports?
Here is the relevant code
class Conference < ActiveRecord::Base
has_many :courses, :dependent => :destroy
end
class Course < ActiveRecord::Base
belongs_to :conference
has_many :sessions, :dependent => :destroy
has_one :manual
# just a place holder method so we can serialize it
def pre_requisite
"An open mind"
end
end
class Session < ActiveRecord::Base
belongs_to :courses
has_one :presentation, :dependent=>:destroy
# just a place holder method so we can serialize it
def maximum_capacity_reached?
false;
end
end
class Presentation < ActiveRecord::Base
belongs_to :session
belongs_to :instructor
end
class Manual < ActiveRecord::Base
belongs_to :course
end
class Instructor < ActiveRecord::Base
end
Now let's suppose I have a controller that will return the full detail
of a conference and needs all of the related data and will also
serialize some custom methods.
class ConferencesController < ApplicationController
# GET /conferences/:id
def show
conference_id = params[:id]
respond_to do |format|
format.html # unsupported
format.json {
render(:json=>Conference.full_json(conference_id))
}
format.xml {
render(:xml=>Conference.full_xml(conference_id))
}
end
end
end
So I've extended the conference class so that it can build this nested
xml along with the result of selective methods on various classes.
class Conference < ActiveRecord::Base
has_many :courses, :dependent => :destroy
def slogan
"#{name}: Be here or be in the dark!"
end
def self.full_xml(conference_id)
# ensure we've loaded the full structure in the most efficient
manner
conference = Conference.find(conference_id, :include=>{:courses
=>
[:manual, {:sessions=>:presentation}]})
# extract detailed hierarchical xml
conference.to_xml do |xml|
xml.slogan conference.slogan # output the banner
#iterate courses and any custom methods
xml.courses{
conference.courses.each do |course|
course.to_xml(:builder=>xml,
:skip_instruct => true) do |
xml_course|
xml_course.sessions{
#iterate sessions and
any custom methods
course.sessions.each do
|session|
session.to_xml(:builder=>xml_course, :skip_instruct => true)
do |xml_course_session|
xml_course_session.is_at_capacity
session.maximum_capacity_reached?
end
end
}
end
end
}
end
end
def self.full_json(conference_id)
# ensure we've loaded the full structure in the most efficient
manner
conference = Conference.find(conference_id, :include=>{:courses
=>
[:manual, {:sessions=>:presentation}]})
debugger()
# extract detailed hierarchical xml
conference.to_json do |json|
json.slogan conference.slogan # output the banner
#iterate courses and any custom methods
json.courses{
conference.courses.each do |course|
course.to_json(:builder=>json,
:skip_instruct => true) do |
json_course|
json_course.sessions{
#iterate sessions and
any custom methods
course.sessions.each do
|session|
session.to_json(:builder=>json_course, :skip_instruct => true)
do |json_course_session|
json_course_session.is_at_capacity
session.maximum_capacity_reached?
end
end
}
end
end
}
end
end
end
When I invoke the method, via http://localhost:3000/conferences/1.xml,
I get the desired generated XML output:
<conference>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<id type="integer">1</id>
<name>Ruby Live</name>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<slogan>Ruby Live: Be here or be in the dark!</slogan>
-
<courses>
-
<course>
<conference-id type="integer">1</conference-id>
<course-name>Action Controller: In Depth</course-name>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<id type="integer">1</id>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
-
<sessions>
-
<session>
<course-id type="integer">1</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-04T15:59:41-08:00</end-time>
<id type="integer">1</id>
<rating type="integer">4</rating>
<room-number>101</room-number>
<start-time type="datetime">2008-12-04T13:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
-
<session>
<course-id type="integer">1</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-05T15:59:41-08:00</end-time>
<id type="integer">2</id>
<rating type="integer">4</rating>
<room-number>101</room-number>
<start-time type="datetime">2008-12-05T13:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
</sessions>
</course>
+
<course>
<conference-id type="integer">1</conference-id>
<course-name>Active Record: In Depth</course-name>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<id type="integer">2</id>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
-
<sessions>
-
<session>
<course-id type="integer">2</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-04T17:59:41-08:00</end-time>
<id type="integer">3</id>
<rating type="integer">5</rating>
<room-number>201</room-number>
<start-time type="datetime">2008-12-04T15:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
-
<session>
<course-id type="integer">2</course-id>
<created-at type="datetime">2008-11-04T13:59:41-08:00</created-at>
<end-time type="datetime">2008-12-05T17:59:41-08:00</end-time>
<id type="integer">4</id>
<rating type="integer">5</rating>
<room-number>201</room-number>
<start-time type="datetime">2008-12-05T15:59:41-08:00</start-time>
<updated-at type="datetime">2008-11-04T13:59:41-08:00</updated-at>
<is_at_capacity>false</is_at_capacity>
</session>
</sessions>
</course>
</courses>
</conference>
When I invoke the method, via http://localhost:3000/conferences/1.json,
I get the following undesired generated json output. Basically the
builder and block that acts on to_xml is ignored or defunct.
{"name": "Ruby Live", "updated_at": "2008/11/04 13:59:41 -0800", "id":
1, "created_at": "2008/11/04 13:59:41 -0800"}
I need to support both xml and json formats while returning the same
data. Can someone please tell me what if there is a plugin or newer
version of Rails that will add this same support for to_json that
to_xml supports?
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Talk" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---
