Question

选择user_id后，collection_select :challenge_id只能显示user_id的挑战，而不是列出所有挑战？

<%= f.collection_select :user_id, User.order(:name),:id, :full_name, include_blank: true %>w
  will
<%= f.collection_select :challenge_id, Challenge.order(:deadline),:id, :full_challenge, include_blank: true %>.

更新

<%= f.collection_select :user_id, User.order(:name),:id, :full_name, include_blank: true, id: "id_of_the_user_id_select_box" %>w
  will
<%= f.collection_select :challenge_id, Challenge.order(:deadline),:id, :full_challenge, include_blank: true %>.

<script>
  $( "#id_of_the_user_id_select_box" ).change(function() {
       $.ajax({
          type: "GET",
          url: '<%= user_challenges_path %>',
          data: {name: $('#id_of_the_user_id_select_box').prop('value')}
       });
  });
</script>

challenges_controller

def user_challenges
  # Not sure what to add in here
end

Answer 1

在选择user_id时触发ajax请求。像：

$( "#id_of_the_user_id_select_box" ).change(function() {
     $.ajax({
        type: "GET",
        url: '<%= fetch_chanllenges_of_user_path %>', # replace by your route
        data: {name: $('#id_of_the_user_id_select_box').prop('value')}
     });
});

在routes.rb文件上使用GET类型创建新路由。在该方法中，您获得了user_id。现在找到该用户的各自挑战。然后使用部分替换第二个下拉列表。

修改

创建名为_user_challenges.html.erb的新部分文件，并将以下代码粘贴到该文件

<div id="dropdown-no-2"> <%= collection_select 'challenge_id', challenges,:id, :full_challenge, include_blank: true %>. </div>

在您的视图文件中，而不是使用第二个下拉列表，请使用此新创建的部分，如：

<%= f.collection_select :user_id, User.order(:name),:id, :full_name, include_blank: true, id: "id_of_the_user_id_select_box" %>w will # below code will be replaced <%= f.collection_select :challenge_id, Challenge.order(:deadline),:id, :full_challenge, include_blank: true %>. # by <%= render :partial => 'user_challenges', locals: {challenges: Challenge.order(:deadline)} %> # If you are using an intelligent IDE then the file path of user_challenges.html.erb file will be given as suggestion

在控制器中：

def user_challenges # fetch challenges for a specific user # I assumed that you've a one to many association between user and challenge @user = User.find(params[:name]) @challenges = @user.challenges.order(:deadline) end

现在，对于控制器的user_challenges方法，创建一个名为user_challenges.js.erb的视图文件。在该文件上写下以下内容：

$("#dropdown-no-2").html('<%=j render :partial => "user_challenges", locals: {challenges: @challenges} %>');

您也可以查看this。

collection_select选项是否更改了secondary_select的选项？

更新

1 个答案: