javascript - RJS:Ajaxified select_tag

Question

因为我在 last question 上没有得到预期的答案我会尽量简化和缩小我的问题:

How can I build a dropdown-menu that uses AJAX (no submit-button) to call the show action of a certain controller?

给出了以下内容:

Model-Association 是 Categories HABTM Projects，因此下拉菜单包含所有类别名称。

应在其中实现下拉菜单的部分 View 。下拉菜单下方是应根据下拉菜单中的选择更改的项目列表:

   <!-- placeholder for AJAX dropdown menu -->

   <!-- list of projects related to categories chosen by the select tag -->
   <ul class="projects">
     <% @projects.each do |_project| %>
       <li>
         <%= link_to(_project.name, _project) %>
       </li>
     <% end %>
   </ul>

具有应调用的显示操作的类别 Controller :

class CategoriesController < ApplicationController
  def show
    # params[:id] should be the choice the user made in the dropdown menu
    @category = Category.find(params[:id])
    @projects = @category.projects.find(:all)

    respond_to do |format|
      format.html # show.html.erb
      format.js   # needed for ajax response?
    end
  end

  def index
    @projects = Category.find(params[:id]).projects.find(:all)
    @category = @project.categories.first

    respond_to do |format|
      format.html # index.html.erb
    end
  end 
end

在 Categories Controller 中调用 show-action 的路由:

category GET    /categories/:id    {:controller=>"categories", :action=>"show"}

您将如何实现？非常感谢任何帮助!

Answer 1

这个怎么样:

<% form_for :category, :url => { :action => "show" } do |f| %>
  <%= select_tag :id, options_from_collection_for_select(Category.find(:all), :id, :name),
  { :onchange => "this.form.submit();"} %>
<% end %>

这将调用传统的 html 调用，因此它将刷新整个页面(并响应 format.html)。

然后 Controller 会根据提交的[:id]找到类别

@category = Category.find(params[:id])