Rails nested form attributes not saving -

using rails 4 , ruby 2.

having trouble saving nested attributes nested form. can see parameters coming through form after submitting. have 2 tables: documents , salary_reports. have checked logs , table receives insert salary_reports, not documents. problem?

models:

class salaryreport < activerecord::base    status = %w[new waiting_for_approval approved dissaproved]    belongs_to :user    has_many :documents    accepts_nested_attributes_for :documents end   class document < activerecord::base      types = %w[sales valuation mileage expense]      belongs_to :salary_report end 

controller

def new     @salary_report = salaryreport.new     @salary_report.documents.build   end    def create     @salary_report = salaryreport.new(salary_report_params)      if @salary_report.save        redirect_to salary_reports_path, notice: "lönerapporten sparades korrekt!"     else       render :new, notice: "något gick fel när lönerapporten skulle sparas!"           end    end  private   def salary_report_params     params.require(:salary_report).permit(:user_id, :approved_by_admin_id, :status,        :comment_from_created_by, :comment_from_admin, :total_sales_since_year_start, :date_sent,       :date_of_approval, :total_buffer, :salary_period, documents_attributes: [:id, :description, :type,      :total])  end 

log after submitting form:

started post "/salary_reports" 127.0.0.1 @ 2013-07-18 10:36:53 +0200 processing salaryreportcontroller#create html parameters: {"utf8"=>"✓",     "authenticity_token"=>"kige4nyvvxnwuhb7jbqdixxcv+2enfxy7m1gbrxgby0=", "salary_report"=>    {"user_id"=>"1", "approved_by_admin_id"=>"", "status"=>"new",     "total_sales_since_year_start"=>"", "date_sent"=>"2013-07-18", "total_buffer"=>"",     "salary_period(3i)"=>"1", "salary_period(2i)"=>"7", "salary_period(1i)"=>"2013",     "comment_from_created_by"=>"comments"}, "documents"=>{"description"=>"something",     "type"=>"sales", "total"=>"2323"}, "commit"=>"skicka till admin för godkännande"}    (0.1ms)  begin transaction    sql (0.8ms)  insert "salary_reports" ("comment_from_created_by", "created_at",     "date_sent", "salary_period", "status", "updated_at", "user_id") values (?, ?, ?, ?, ?, ?,     ?)  [["comment_from_created_by", "comments"], ["created_at", thu, 18 jul 2013 08:36:53 utc     +00:00], ["date_sent", thu, 18 jul 2013 00:00:00 utc +00:00], ["salary_period", mon, 01 jul     2013 00:00:00 utc +00:00], ["status", "new"], ["updated_at", thu, 18 jul 2013 08:36:53 utc     +00:00], ["user_id", 1]]    (4.4ms)  commit transaction    (0.2ms)  begin transaction    (0.2ms)  commit transaction redirected http://localhost:3000/salary_reports completed 302 found in 62ms (activerecord: 5.7ms) 

the view looks this:

<%= form_for @salary_report, :html => { :class => "well"} |f| %>     <%= f.label :salary_period %>    <%= f.date_select :salary_period, :as => :date, :order => [:month, :year] %>    <%= f.label :comment_from_created_by %>    <%= f.text_area :comment_from_created_by %>    <%= f.label :comment_from_admin %>    <%= f.text_area :comment_from_admin, :disabled => true %>    <%= fields_for :documents |builder| %>        <%= render "document_fields", :f => builder %>    <% end %>     <%= link_to_add_fields "ny rad", f, :documents %>            <%= f.submit "skicka till admin för godkännande", disable_with: 'skickar....', :class => "btn btn-success" %>  <% end %> 

try adding f. before fields_for

<%= f.fields_for :documents |builder| %>   <%= render "document_fields", :f => builder %> <% end %>