How can I pass an object to rabl views from rake task - ruby-on-rails-3

Question

I am trying to create a json file from a rake task using rabl. Below I have the simplified version to test with.
When I view 'articles.json' or 'articles/2.json' via the url, I get the expected json response.
But when I try to run it via the rake task, it always has a null value for #articles in the jsonFile created. It will render the index.json.rabl view the same number of times as #articles.count, but the values are always null.
So how do I pass in the #articles object created in my rake task to Rabl.render?
index.json.rabl
#feedName ||= 'default'
node(:rss) { partial('articles/rss), :object => #feedName }
node(:headlines) { partial('articles/show'), :object => #articles }
show.json.rabl
object #article
attributes :id,:body
....
exports.rake
task :breakingnews => :config do
filename = 'breakingnews.json'
jsonFile = File.new(filename)
#articles = Article.limit(10)
n = Rabl::renderer.json(#articles,'articles/index',view_paths => 'app/views')
jsonFile.puts b
jsonFile.close

Answer 1

I ran into a similar problem. You basically have 2 options:
Pass a single object explicitly as a parameter
Pass multiple objects implicitly by scope
By Parameter
In your task
#your_object = ...
Rabl.render(#your_object, 'your_template', view_paths => 'relative/path/from/project/root', :format => :json)
In your Rabl Template
object #any_name_you_like
attributes :id,:body
....
This will render your template as a json with the object specified as its instance object (you can name it anything you want)
By Scope
This is a bit more tricky. The only option I found is by setting the desired objects as instance variables in the calling scope and set this scope for the rendering of the template (see scope).
In your task
#one_object = ...
#another_object = ...
Rabl.render(nil, 'your_template', view_paths => 'relative/path/from/project/root', :format => :json, :scope => self)
In your Rabl Template
object #one_object
attributes :id,:body
node(:my_custom_node) { |m| #another_object.important_stuff }