No route matches {:action=>"show", :controller=>"restaurants"} - ruby-on-rails-3

Question

If I want to go with my home page clicking on the map localhost:3000/maps gets out this error No route matches {:action=>"show", :controller=>"restaurants"}
controllers/maps_controller.rb
def index
#maps = Map.all
#json = Map.all.to_gmaps4rails do |map, marker|
marker.infowindow info_for_restaurant(map.restaurant)
end
respond_to do |format|
format.html # index.html.erb
format.json { render json: #maps }
end
end
def show
#map = Map.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.json { render json: #map }
end
end
private
def info_for_restaurant(restaurant)
link_to restaurant_path do
content_tag("h2") do
restaurant.name
end
end
end
routes.rb
resources :restaurants
resources :maps
This is answer for my question:
controllers/maps_controller.rb
def index
#maps = Map.all
#json = Map.all.to_gmaps4rails do |map, marker|
marker.infowindow render_to_string(:partial => "/maps/maps_link",
:layout => false, :locals => { :map => map})
end
respond_to do |format|
format.html # index.html.erb
format.json { render json: #maps }
end
end
views/maps/_maps_link.html.erb
<div class="map-link">
<h2><%= link_to map.restaurant.title, map.restaurant %></h2>
</div>

Answer 1

You referred to restaurant_path within info_for_restaurant, which is part of MapsController. Rails met error here.
You need to either define the restaurant_path in restaurant controller, or comment out this function in maps controller at this moment.

Answer 2

Your approach is wrong in several levels. Let's work on them, one at a time:
1) Your call to the route helper is wrong:
restaurant_path is the route helper for a show action. A show action needs an id parameter to be valid. Your call is missing a parameter.
So, your code must be something like this:
def info_for_restaurant(restaurant)
link_to restaurant_path(restaurant) do
content_tag("h2") do
restaurant.name
end
end
end
To see the parameters needed for each action, you can run rake routes on the console.
However, this does not solve the problem, as you're also:
2) Calling view helpers from your controller
link_to and content_tag are view helper methods, and you don't want to bother your controller with view issues. So, the best way to solve this problem is to move your info_for_restaurant method to a helper, and call it from a view instead.
So, now, your controller will not assign anything to #json, and the last line of your view will look like this:
<%= gmaps4rails #maps.to_gmaps4rails {|map, marker| marker.infowindow info_for_restaurant(map.restaurant) } %>