Why aren't params being passed?

Why aren't :q params passing to the controller?!

Here's the controller code:

  def advanced_search
      @search = Isbn.where(:client_id => current_user.client_id).search(params[:q])
      @search.build_grouping unless @search.groupings.any?
      @isbns  = params[:distinct].to_i.zero? ? @search.result : @search.result(distinct: true)
      respond_with @isbns
    end

Here's application_helper with the build_grouping bit it:

  def setup_search_form(builder)
    fields = builder.grouping_fields builder.object.new_grouping, object_name: 'new_object_name', child_index: "new_grouping" do |f|
      render('grouping_fields', f: f)
    end

Here's the form:

<%= search_form_for @search, url: advanced_search_isbns_path, html: {method: :post} do |f| %>
<% setup_search_form f %>
  #...
<%= render 'results' %>

Here's the trace:

  Processing by IsbnsController#advanced_search as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"P074clk3UDe3cNNEG6IZ6TXm2q+fr8dMJfJwSBSx/1c=", "q"=>{"g"=>{"0"=>{"m"=>"or"}}}, "commit"=>"Search"}

Here's the source of search_form_for:

# File 'lib/ransack/helpers/form_helper.rb', line 4

def search_form_for(record, options = {}, &proc)
  if record.is_a?(Ransack::Search)
    search = record
    options[:ur开发者_如何学Pythonl] ||= polymorphic_path(search.klass)
  elsif record.is_a?(Array) && (search = record.detect {|o| o.is_a?(Ransack::Search)})
    options[:url] ||= polymorphic_path(record.map {|o| o.is_a?(Ransack::Search) ? o.klass : o})
  else
    raise ArgumentError, "No Ransack::Search object was provided to search_form_for!"
  end
  options[:html] ||= {}
  html_options = {
    :class  => options[:as] ? "#{options[:as]}_search" : "#{search.klass.to_s.underscore}_search",
    :id => options[:as] ? "#{options[:as]}_search" : "#{search.klass.to_s.underscore}_search",
    :method => :get
  }
  options[:as] ||= 'q'
  options[:html].reverse_merge!(html_options)
  options[:builder] ||= FormBuilder

  form_for(record, options, &proc)
end

Here's the source of search:

# File 'lib/ransack/search.rb', line 16

def initialize(object, params = {}, options = {})
  params ||= {}
  @context = Context.for(object)
  @context.auth_object = options[:auth_object]
  @base = Nodes::Grouping.new(@context, 'and')
  build(params.with_indifferent_access)
end

In fact, here's the whole chuffing lot.

Plus: all the routes for the model, included for completeness:

   resources :isbns, only: :index do
    match 'advanced_search' => 'isbns#advanced_search',
    on: :collection, via: [:get, :post], as: :advanced_search   
  end

  resources :isbns do
    get :profit,   :on => :member
    get :workings,   :on => :member
    put :copyisbn, :on => :member
    get :onixxml, :on => :member
    collection do
      post 'edit_multiple'
      put 'update_multiple'
      get 'onix'
      get 'add_subschemes'
      get 'xmp'
      get 'profitindex'
      delete 'destroy_multiple' 

    end 

  end

The models file is very busy, so do ask for more, but here are some of the associations: Isbn.rb: attr_accessible :marketingtexts_attributes, :prices_attributes #etc has_many :marketingtexts, :dependent => :destroy has_many :supplies, :dependent => :destroy

Marketingtext.rb

  attr_accessible :user_id, :created_at, :legacycode, :updated_at, :client_id, :isbn_id,  #etc
  belongs_to :isbn
  before_save :map_legacy_codes
  validates :client_id, :presence => true

Supply.rb

  attr_accessible :user_id, :client_id, :isbn_id, :prices_attributes, #etc
  belongs_to :isbn
  has_many   :supplydetails, :dependent => :destroy
  has_many  :prices, :through => :supplydetails
  accepts_nested_attributes_for :supplydetails

I can run the cloned ransack demo code on my machine. In my own app, I've excluded all the javascript except jquery and the search script. I'm increasingly thinking it's a conflict with another gem or some bit of code.