如何在Rails中根据表单输入动态更新搜索结果?

Question

我希望网站访问者能够在可以通过下拉表单输入的半径内查看附近的节目。我有一个视图，使用Geocoder gem显示附近的节目:

<h3> Shows near <%= request.location.city %> </h3>
<%= form_for @nearby_shows.first do |f| %>
<p> Radius (in miles): <%= f.select(:radii, [10,20,30,40,50], {},
   :style => "width:50px", :selected => f.object.radii, :onchange =>
   "location.href = '#{shows_path}'") %> </p>
<% end %>
<ul class="users">
  <% @nearby_shows.each do |nearby_show| %>
    <li>
      <%= link_to nearby_show.show_name, nearby_show %>
    </li>
  <% end %>
</ul>

现在选择不影响任何东西，并且当页面刷新时，选择不会在表单中被记住。

模型，显示。rb:包含

attr_accessor :radii

显示控制器包含:

def index
    @shows = Show.all
    @radii = 50
    @nearby_venues = Venue.near("Boulder, CO",@radii,:select =>
    "id").to_a
    @nearby_shows = Show.where(show_venue: @nearby_venues)
end

在生产中，我将使用request.location。城市，但在开发中，我只是以"Boulder, CO"为例。

如何使用输入选择表单设置@radii ?我担心form_for将不允许我更改实体列表@nearby_shows的变量。

Answer 1

如果您想要一个快速的AJAX解决方案，我会这样做

首先，为列表添加一个ID，以便于操作

<ul id="my_id" class="users"></ul>

我真的不明白你为什么需要那个<%= form_for @nearby_shows.first %> ?如果我理解得好，你只是想显示一个选择，并根据用户选择的内容更新附近的节目列表?

routes.rb

resource :shows do
  get 'update_nearby', on: :collection, constraints: { format: 'js' }
end
# GET /shows/update_nearby, meant to be used only with AJAX

your_view.html.erb

<%= form_tag update_nearby_shows_path, remote: :true do |f| %>
<p> Radius (in miles): <%= select_tag(:radii, [10,20,30,40,50], {},
   :style => "width:50px", :selected => @radii, :onchange =>
   "location.href = '#{shows_path}'") %> </p>
<% end %>
<!-- On Submit, it will request a JS response 
     You can add some JS to submit the form everytime the select changes -->

添加一些JS特定的响应

your_controller.rb

def update_nearby
  find_nearby_shows
end
private
def find_nearby_shows
  @radii = params[:radii] ? params[:radii] : 50
  @nearby_venues = Venue.near("Boulder, CO",@radii,:select =>
    "id").to_a
  @nearby_shows = Show.where(show_venue: @nearby_venues)
end

update_nearby.js.erb

<% if @nearby_shows %>
  // Empty the list
  var id = $("#my_id").empty()
  <% @nearby_shows.each do %>
    // Add one <li> per show
    $("<li>", { 'html': "<%= escape_javascript(link_to(nearby_show.show_name, nearby_show)) %>"}).appendTo(id)
  <% end %>
<% end %>

奖励:你说你想保存半径?你可以尝试将它添加到用户会话

def index
  ...
  @radii = session[:saved_radii] ? session[:saved_radii] : DEFAULT_RADIUS
  ...
end
def update_nearby
   find_nearby_shows
   session[:saved_radii] = @radii
end

但如果你真的想为用户保存它，你应该在你的用户模型中有一个preferred_radii字段