【发布时间】：2017-04-11 20:32:22
【问题描述】：
我第一次尝试在简单的 Rails 应用程序中实现 Ajax，主要由本教程提供帮助：
我的应用有一个特定的显示视图，我想在其中显示一个排行榜，该排行榜呈现用户列表和他们的记录，以及一个可以创建新用户/记录的表单。
我想通过 Ajax 实现这一点，但每次我尝试提交 Ajax 请求时，我都会收到一个 500 错误，指向下面的 JQuery 行并抛出“加载资源失败”消息。
xhr.send( ( options.hasContent && options.data ) || null );
我尝试更改了一些内容但没有成功，包括在表单中使用 remote:true 以及直接使用 JQuery 发出 Ajax 请求。你能指出我这里潜在的问题吗？相关代码下方：
leaderboards_Controller显示动作呈现相关排行榜
def show
@leaderboard = Leaderboard.find(params[:id])
@leaders = @leaderboard.leaders
@leader = Leader.new(persisted_time: @persisted_time)
end
排行榜/show.html.erb
<%= simple_form_for([@leaderboard, @leader], html: { class: 'form-inline', id:'leader-form' }) do |f| %>
<%= f.error_notification %>
<div class="form-inputs">
<%= f.input :name, :label => false, :placeholder => "Your name here", :required => true, :autofocus => true %>
<%= f.input :record_time, :label => "Your record", input_html: {readonly: ''} %>
<%= f.button :submit %>
</div>
<% end %>
<ul>
<% @leaders.each do |leader| %>
<li>
<%= leader.name %> |
<strong>record: </strong><%= leader.record_time %> <br />
</li>
<% end %>
</ul>
leaders_Controller我打算在提交上面的表单时将Ajax请求发送到这个控制器中的创建操作
class LeadersController < ApplicationController
before_action :set_leader, only: [:show, :edit, :update, :destroy]
before_action :set_leaderboard, only: [:create, :new]
def index
@leaders = Leader.all
end
def show
end
def new
end
def edit
end
def create
@leaderboard = Leaderboard.find(params[:leaderboard_id])
@leader = Leader.new(leader_params)
@leader.leaderboard_id = @leaderboard.id
respond_to do |format|
if @leader.save
format.json { render json: @leader, status: :created}
else
format.json { render json: @leader.errors, status: :unprocessable_entity }
end
end
end
def update
@leader.update_attributes(leader_params)
end
def destroy
@leader.destroy
end
private
def set_leader
@leader = Leader.find(params[:id])
end
def set_leaderboard
@leaderboard = Leaderboard.find(params[:leaderboard_id])
end
def leader_params
params.require(:leader).permit(:name, :record_time, :leaderboard_id)
end
end
assets/javascripts/leaders.js我正在执行 Ajax 请求的 JS 文件
$(function(){
$("form").submit(function(event){
event.preventDefault();
var action = $(this).attr('action');
var method = $(this).attr('method');
var name = $(this).find('#leader_name').val();
var record_time = $(this).find('#leader_record_time').val();
$.ajax({
method: method,
url: action,
data: { name: name, record_time: record_time }
});
});
});
和路线
resources :leaderboards, shallow: true do
resources :leaders
end
我显然不了解 Ajax。如果您指出正确的方向，我将不胜感激。
这是我提交表单后在控制台中得到的输出
jquery.self-bd7ddd3….js?body=1:10255 POST http://localhost:3000/leaderboards/1/leaders 500 (Internal Server Error)
这导致 JQuery 脚本中的这一行：
xhr.send( ( options.hasContent && options.data ) || null );
并产生：
Failed to load resource: the server responded with a status of 500 (Internal Server Error)
和服务器日志
Started POST "/leaderboards/1/leaders" for ::1 at 2016-11-28 21:42:24 +1100
Processing by LeadersController#create as JS
Parameters: {"utf8"=>"✓", "leader"=>{"name"=>"9089sdas8dds", "persisted_time"=>"5"}, "commit"=>"S", "leaderboard_id"=>"1"}
Leaderboard Load (0.5ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
CACHE (0.0ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
(0.2ms) BEGIN
Leaderboard Load (0.4ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
SQL (2.6ms) INSERT INTO "leaders" ("name", "persisted_time", "leaderboard_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["name", "9089sdas8dds"], ["persisted_time", "5"], ["leaderboard_id", 1], ["created_at", 2016-11-28 10:42:24 UTC], ["updated_at", 2016-11-28 10:42:24 UTC]]
(2.2ms) COMMIT
Completed 201 Created in 15ms (Views: 0.8ms | ActiveRecord: 5.9ms)
Started POST "/leaderboards/1/leaders" for ::1 at 2016-11-28 21:42:27 +1100
Processing by LeadersController#create as JS
Parameters: {"utf8"=>"✓", "leader"=>{"name"=>"9089sdas8dds", "persisted_time"=>"5"}, "commit"=>"S", "leaderboard_id"=>"1"}
Leaderboard Load (0.5ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
CACHE (0.0ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
(0.7ms) BEGIN
Leaderboard Load (0.5ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
SQL (1.9ms) INSERT INTO "leaders" ("name", "persisted_time", "leaderboard_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["name", "9089sdas8dds"], ["persisted_time", "5"], ["leaderboard_id", 1], ["created_at", 2016-11-28 10:42:27 UTC], ["updated_at", 2016-11-28 10:42:27 UTC]]
(0.5ms) COMMIT
Completed 201 Created in 14ms (Views: 1.0ms | ActiveRecord: 4.2ms)
Started POST "/leaderboards/1/leaders" for ::1 at 2016-11-28 21:42:29 +1100
Processing by LeadersController#create as JS
Parameters: {"utf8"=>"✓", "leader"=>{"name"=>"9089sdas8dds", "persisted_time"=>"5"}, "commit"=>"S", "leaderboard_id"=>"1"}
Leaderboard Load (0.6ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
CACHE (0.0ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
(0.2ms) BEGIN
Leaderboard Load (0.6ms) SELECT "leaderboards".* FROM "leaderboards" WHERE "leaderboards"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
SQL (2.3ms) INSERT INTO "leaders" ("name", "persisted_time", "leaderboard_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["name", "9089sdas8dds"], ["persisted_time", "5"], ["leaderboard_id", 1], ["created_at", 2016-11-28 10:42:29 UTC], ["updated_at", 2016-11-28 10:42:29 UTC]]
(2.3ms) COMMIT
Completed 201 Created in 14ms (Views: 0.7ms | ActiveRecord: 6.0ms)
【问题讨论】：
标签： javascript jquery ruby-on-rails ajax