Adding Parameters to Backbone.js collection causing ArgumentError (wrong number of arguments ... for filter method

Adding Parameters to Backbone.js collection causing ArgumentError (wrong
number of arguments ... for filter method

I can sync with my backbone server perfectly well using the
collection.fetch method
UserActionCollection extends Backbone.Collection
url: "/api/user_actions"
model: UserActionModel
userActions = new UserActionCollection()
userActions.fetch()
This fills up my collection with the expected models
However when I attempt to add a data filter
userActions.fetch({data: $.param({collabList: true })})
My ruby on rails server pops up this error:
Processing by UserActionsController#index as JSON
Parameters: {"collabList"=>"true"}
Completed 500 Internal Server Error in 9214ms
ArgumentError (wrong number of arguments (0 for 1..2)):
app/models/user_action.rb:16:in `filter_by_params'
app/controllers/user_actions_controller.rb:14:in `index'
My Controller for the index fetch is:
def index
respond_with UserAction.filter_by_params(params)
end
My Model Definition with the definition for filter_by_params
class UserAction < ActiveRecord::Base
attr_accessible :action, :context, :itemID, :itemType, :userId,
:userName, :userEmail
def self.filter_by_params(params)
scoped = self.scoped
if (params[:collabList])
scoped = scoped.uniq.pluck(:userName)
end
return scoped
end
end
I stuck a binding.pry at the controllers index method and when I call
userActions.fetch() the params value is:
[1] pry(#<UserActionsController>)> params
=> {"action"=>"index", "controller"=>"user_actions"}
And everything works when I continue.
When I call the userActions.fetch({data: $.param({collabList: true })})
you can see the params value below:
12: def index
=> 13: binding.pry
14: respond_with UserAction.filter_by_params(params)
15: end
[1] pry(#<UserActionsController>)> params
=> {"collabList"=>"true", "action"=>"index", "controller"=>"user_actions"}
When I type next and process line 14, It throws an exception
#<ArgumentError: wrong number of arguments (0 for 1..2)>
Am I passing in parameters incorrectly?
Is there some reason the params variable isn't being passed in?
Thanks for any help/insight you can give me!