我正在开发一个prototyp(rails 2.2.2)来创建一个类似于http://www.redbeacon.com/s/b/的业务目录的页面结构。
目标应该是以下路径:mysite.com/d/state/location/ ...显示某事物的索引。到目前为止,我做了以下......
控制器和型号:
$ ruby script/generate controller Directories index show
$ ruby script/generate controller States index show
$ ruby script/generate controller Locations index show
$ ruby script/generate model State name:string abbreviation:string
$ ruby script/generate model Location name:string code:string state_id:integer
$ rake db:migrate
路线:
map.states '/d', :controller => 'states', :action => 'index'
map.locations '/d/:state', :controller => 'locations', :action => 'index'
map.directories '/d/:state/:location', :controller => 'directories', :action => 'index'
......建立在模型中的关系:
class State < ActiveRecord::Base
has_many :locations
end
class Location < ActiveRecord::Base
belongs_to :states
end
...向控制器添加了操作:
class StatesController < ApplicationController
def index
@all_states = State.find(:all)
end
end
class LocationsController < ApplicationController
def index
@all_locations = Location.find(:all)
@location = Location.find_by_id(params[:id])
end
end
class DirectoriesController < ApplicationController
def index
@location = Location.find_by_id(params[:id])
@all_tradesmen = User.find(:all)
end
end
州指数视图
<h1>States#index</h1>
<p>Find me in app/views/states/index.html.erb</p>
<br><br>
<% for state in @all_states %>
<%= link_to state.name, locations_path(state.abbreviation.downcase) %>
<% end %>
地点索引视图
<h1>Locations#index</h1>
<p>Find me in app/views/locations/index.html.erb</p>
<br><br>
<% for location in @all_locations %>
<%= link_to location.name, directories_path(location.state.abbreviation, location.name) %>
<% end %>
但是我被卡住了,我收到以下错误消息:
NoMethodError in Locations#index
Showing app/views/locations/index.html.erb where line #6 raised:
undefined method `state' for #<Location:0x104725920>
Extracted source (around line #6):
3: <br><br>
4:
5: <% for location in @all_locations %>
6: <%= link_to location.name, directories_path(location.state.abbreviation, location.name) %>
7: <% end %>
任何想法为什么会弹出此错误消息?或者一般来说是否有更好的方法?
答案 0 :(得分:2)
您应该看到的代码部分是:
class Location < ActiveRecord::Base
belongs_to :states
end
它应该是
class Location < ActiveRecord::Base
belongs_to :state
end
另一个注意事项,虽然与您所获得的错误无关,但Ruby程序员通常更喜欢array.each
而不是for item in array
。