Ajax 在 Rails 中为多个模型形成局部

Question

我有这段 AJAX 代码（取自：http://badpopcorn.com/blog/2008/09/11/rails-observer-field/），它出现在许多视图（主要是 new.html.erb 和 edit.html.erb）中。为了避免代码重复，我假装使用部分：

app/views/cities/_state_city_form.html.erb

<p> State:
  <%= select(:state, :state_name, City.all(:select => 'DISTINCT(state)', :order => :state).collect {|c| [ c.state.titleize, c.state ] }, {:include_blank => true})%>
  <%= observe_field 'state_state_name', :url => { :action => :by_state,
                                                  :controller => :cities },
                                                  :update => 'cities_list',
                                                  :with => "'state='+ $('#state_state_name').val()" %>
</p> City:
  <div id="cities_list">
    <%= select(modelname.to_sym, :city_id, [], {:include_blank => true})%>
  </div>
<p>
</p>

我还有 Ajax 回调内容：

app/views/cities/by_state.html.erb

<%= select(/*PROBLEM_HERE*/, :city_id, @cities.collect {|c| [ c.name, c.id ] }, {:include_blank => true})%>

还有我的城市管理员：

app/controllers/cities_controller.rb

class CitiesController < ApplicationController

  def by_state
    @cities = City.find_all_by_state(params[:state])
    render :layout => false
  end

end

然后我会简单地在需要的地方调用部分：

app/views/user/new.html.erb

...
<%= render :partial => 'cities/state_city_form', :locals => { :modelname => :user } %>
...

app/views/employee/new.html.erb

...
<%= render :partial => 'cities/state_city_form', :locals => { :modelname => :employee } %>
...

在这里我可以将 :user 或 :employee 传递给部分，但是如何将它们传递给 Ajax 回调？

Answer 1

您可以尝试将模型名称作为字符串传递给部分，并使用 to_sym 将其转换为符号。

希望这会有所帮助。