Render simple JSON array with RABL in Rails - ruby-on-rails

I've been trying to figure out how to make RABL render a very simple JSON array of string, such as: ["my,"array","of","strings"]
The controller would be
class StringsController < ApplicationController
responds_to :json
def index
#string = ['my','array','of','strings']
respond_with #strings
end
end
And the RABL view must surely start with:
collection #strings, root_object: false
but I cannot figure out how to just output the strings without a node name or within an object...
There is obviously a much more straightforward solution to actually serving up the JSON array, much like what I've put below, but I'm specifically interested in why this seems so complicated in RABL!
class StringsController < ApplicationController
def index
render json: ['my','array','of','strings']
end
end

Neill,
This should work for any arrays, but for your particular array the exact answer is...
In the index.json.rabl use the below code
collection #string, object_root: false
node do |s|
s
en
In your controller use...
def index
#string = ["my","array","of","strings"]
end

To build on top of Mark's answer, I think it works with this:
collection #string, object_root: false
node :value do |s|
s
end
Note I added :value which is the label of the JSON record.

You can do it like that and that need not the rabl view for showing response.
def index
#string = ['my','array','of','strings']
respond_to do |format|
format.json { render :json => {:message => "Success", :my_string => #string } }
format.xml
end
end

Related

How to pass an argument in an method which in being represented as symbol?

I have an action as :
def get_data
#people = Person.all
respond_to do |format|
format.json do
render :json => {
:success => true,
:people => #people.as_json({
:only => [:person_name, :text_description, :text_heading],
:methods => [:title,:age_group],
})
}
end
end
end
Here title and age_group are my methods in model Person
def age_group
self.name
end
Now i want to method to look like this
def age_group(age)
# ...
end
How do i pass this argument from the controller as the methods representation there is as symbol.
Hi as per my suggestion you can override method or create a instance method depending upon options it will generate hash or json.If you want to use as_json then you can dig into code this line is helpful for digging code https://github.com/rails/rails/blob/2-3-stable/activerecord/lib/active_record/serialization.rb#L33 which will give you how methods being passed.

Rails: overriding as_json for dynamic value -- is there a smarter way?

I want to output a list of affiliate links, each tagged to identify the current user. It would be simple in HTML, but we're writing an API, so the output is JSON.
I have it working, but it seems overly complicated. Is this the best approach?
My model, AffiliateLink contains a field (the raw HTML of the link) that I'll transform and output on the fly by adding a token. I have a model method that produces the replacement -- it is non-trivial because we use multiple affiliates and each has a special transformation rule that this method knows about:
def link_with_token(user_token)
# some gnarly code that depends on a lot of stuff the model knows
# that returns a proper link
end
To get my correct link html in JSON I have done these things:
add attr_accessor :link_html to model
add an instance method to set the new accessor
...
def set_link_html(token)
self.link_html = link_with_tracking_token(token)
end
override as_json in the model, replacing the original html_code with link_html
...
def as_json(options = {})
super(:methods => :link_html, :except => :html_code)
end
iterate over the collection returned in the controller method to do the transformation
...
def index
#links = Admin::AffiliateLink.all # TODO, pagination, etc.
respond_to do |format|
format.html # index.html.erb
format.json do
#links.each do |link|
link.set_link_html(account_tracking_token)
end
render json: #links
end
end
end
This seems like a lot of stuff to do just to get my teensy-weensy transformation done. Helpful suggestions (relating to this problem and not to other aspects of the code, which is in flux now) are welcome.
1) A quick solution to your problem (as demonstrated here):
affiliate_links_controller.rb
def index
#links = Admin::AffiliateLink.all # TODO, pagination, etc.
respond_to do |format|
format.html # index.html.erb
format.json do
render json: #links.to_json(:account_tracking_token => account_tracking_token)
end
end
end
AffiliateLink.rb
# I advocate reverse_merge so passed-in options overwrite defaults when option
# keys match.
def as_json(options = {})
json = super(options.reverse_merge(:except => :html_code))
json[:link_with_token] = link_with_token(options[:account_tracking_token])
json
end
2) A more hardcore solution, if you're really writing an API:
See this article describing your problem.
See the gem that the authors made as a solution.
See this railscast on using the gem.
3) And lastly, the convenient solution. If you have a convenient model relation, this is clean:
Pretending AffiliateLink belongs_to :user. And assuming user_token is an accessible attribute of User.
AffiliateLink.rb
# have access to user.user_token via relation
def link_with_token
# some gnarly code that depends on a lot of stuff the model knows
# that returns a proper link
end
def as_json(options = {})
super(options.reverse_merge(:methods => :link_with_token, :except => :html_code))
end
affiliate_links_controller.rb
def index
#links = Admin::AffiliateLink.all # TODO, pagination, etc.
respond_to do |format|
format.html # index.html.erb
format.json do
render json: #links
end
end
end

Cannot access attr_accessor defined variables

I am using Thinking Sphinx to run searches and I get the appropriate ActiveRecord Models fine. The problem is, I want to create an appropriate link path and text on each model, then send the info to the browser in the form of JSON, via AJAX. I am using the following to build those link attributes:
In the controller:
class FindController < ApplicationController
def tag_results
#results = ThinkingSphinx.search(params[:terms])
#results.each do |result|
result.build_ajax_response
end
respond_to do |format|
format.html
format.json { render :json => #results }
end
end
end
In the model:
class TaggedItem < ActiveRecord::Base
attr_accessible :name
attr_accessor :search_link, :search_text
def build_ajax_response
self.search_link = Rails.application.routes.url_helpers.tagged_item_path(self.id)
self.search_text = self.name
end
end
The resulting json object doesn't have either of the search_* attributes listed, much less have a value for them. I've tried using #search_link as well as just search_link in the build_ajax_response method.
Am I doing this wrong? Could there be something else interfering?
Rails' default to_json doesn't know about those extra non active record attributes you've added. The easiest possible thing is probably to specify them as extra methods to include:
format.json { render :json => #results.to_json(:methods => [:search_link, :search_text]) }

Overriding as_json method with params

First of all, I'm using Rails 3.0.6 and Ruby 1.9.2
I have a controller with two different actions, both should return a json object, but with different formats. Therefore I'm overriding the as_json method to write the JSON object in my own format. Problem is that I don't know how to pass params to as_json method since it's being automatically called by Rails.
My code looks like this:
class MyController < ApplicationController
def action1
# my code
respond_to do |format|
# Render with :json option automatically calls to_json and this calls as_json
format.js { render :json => #myobjects }
end
end
def action2
# a different code
respond_to do |format|
# This action should return a JSON object but using a different format
format.js { render :json => #myobjects }
end
end
end
class MyModel < ActiveRecord::Base
def as_json(options = {})
# I would like to add a conditional statement here
# to write a different array depending on one param from the controller
{
:id => self.id,
:title => self.description,
:description => self.description || "",
:start => start_date1.rfc822,
:end => (start_date1 && start_date1.rfc822) || "",
:allDay => true,
:recurring => false
}
end
end
Note that #myobjects are a collection of objects which class is MyModel.
Any help would be appreciated. Thank you!
Call it explicitly in controller and pass params. as_json will return string and calling as_json on string returns itself. It is quite common practice.
respond_to do |format|
# Render with :json option automatically calls to_json and this calls as_json
format.js { render :json => #myobjects.as_json(params) }
end

Excluding some ActiveRecord properties from xml rendering in rails

I have an ActiveRecord model that I would like to convert to xml, but I do not want all the properties rendered in xml. Is there a parameter I can pass into the render method to keep a property from being rendered in xml?
Below is an example of what I am talking about.
def show
#person = Person.find(params[:id])
respond_to do |format|
format.xml { render :xml => #person }
end
end
produces the following xml
<person>
<name>Paul</name>
<age>25</age>
<phone>555.555.5555</phone>
</person>
However, I do not want the phone property to be shown. Is there some parameter in the render method that excludes properties from being rendered in xml? Kind of like the following example
def show
#person = Person.find(params[:id])
respond_to do |format|
format.xml { render :xml => #person, :exclude_attribute => :phone }
end
end
which would render the following xml
<person>
<name>Paul</name>
<age>25</age>
</person>
You can pass an array of model attribute names to the :only and :except options, so for your example it would be:
def show
#person = Person.find(params[:id])
respond_to do |format|
format.xml { render :text => #person.to_xml, :except => [:phone] }
end
end
to_xml documentation
I just was wondering this same thing, I made the change at the model level so I wouldn't have to do it in the controller, just another option if you are interested.
model
class Person < ActiveRecord::Base
def to_xml
super(:except => [:phone])
end
def to_json
super(:except => [:phone])
end
end
controller
class PeopleController < ApplicationController
# GET /people
# GET /people.xml
def index
#people = Person.all
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => #people }
format.json { render :json => #people }
end
end
end
I set one of them up for json and xml on every object, kinda convenient when I want to filter things out of every alternative formatted response. The cool thing about this method is that even when you get a collection back, it will call this method and return the filtered results.
The "render :xml" did not work, but the to_xml did work. Below is an example
def show
#person = Person.find(params[:id])
respond_to do |format|
format.xml { render :text => #person.to_xml(:except => [:phone]) }
end
end
The except is good, but you have to remember to put it everywhere. If you're putting this in a controller, every method needs to have an except clause. I overwrite the serializable_hash method in my models to exclude what I don't want to show up. This has the benefits of not having t put it every place you're going to return as well as also applying to JSON responses.

Resources