custom validations errors form controller inside other parent controller rails 3.1

Question

I have a House model in my rails app that has_many deals. I am displaying these deals on the house's show page. When I submit the form everything works fine if is with redirect_to; however, if there are validation errors on the Deal model, then my system not working fine. If there are validation errors on the Deal model.

In my routes.rb I have

resources :houses do
 resources :deals
end

In deals_controller.rb I have the next method create:

def create 
     @house = House.find_by_slug(params[:house_id])
    @deal = @house.deals.build(params[:deal])
    @deal.user = current_user

    respond_to do |format|
      if @deal.save
        format.html { redirect_to @house, :notice => 'Your offer has been created     successfully'  }
        format.json { render json: @house, status: :created, location: @house }
      else
        format.html { redirect_to @house, :alert => 'Oops, something went wrong. Please     try again' }
        format.json { render json: @house.errors, status: :unprocessable_entity }

      end
    end  
end

With redirect_to working fine, but I can not custom my error message when fail the validation form model.

I have check this method when @deal.save fail:

render :template => 'houses/show'

This method I have seen in Where to render comments controller in Rails on model validations failure?

I would simply like to render the house's But not working for me, because the form have a action to:

/houses/name-of-house/deals

and not redirect to /houses/name-of-house/

How can I get the error validations from form deals (child), in my action show from house controller?

Answer 1

I have the same problem. I think this is a duplicate of Where to render comments controller in Rails on model validations failure? - I am adding my own response there instead.