【发布时间】：2012-01-21 13:55:38
【问题描述】：
我的一段 JavaScript 代码有问题 - 下面显示了一个 sn-p。基本上，代码向 rails 控制器发出 getJSON 请求，然后应该处理返回的数据，构建 HTML 表，然后将其嵌入到 Div 中。它不起作用。我已经尝试通过警报等逐步完成它 - 一切都无济于事。数据是从 rails 控制器检索的，我可以验证这一点。我已将发出和处理 getJSON 请求的代码放在 Rails 欢迎页面的中间——这不是我的全部。代码如下：
<!DOCTYPE html>
<html>
<head>
<title>Ruby on Rails: Welcome aboard</title>
<style type="text/css" media="screen">
body {
margin: 0;
margin-bottom: 25px;
padding: 0;
background-color: #f0f0f0;
font-family: "Lucida Grande", "Bitstream Vera Sans", "Verdana";
font-size: 13px;
color: #333;
}
h1 {
font-size: 28px;
color: #000;
}
a {color: #03c}
a:hover {
background-color: #03c;
color: white;
text-decoration: none;
}
#page {
background-color: #f0f0f0;
width: 750px;
margin: 0;
margin-left: auto;
margin-right: auto;
}
#content {
float: left;
background-color: white;
border: 3px solid #aaa;
border-top: none;
padding: 25px;
width: 500px;
}
#sidebar {
float: right;
width: 175px;
}
#footer {
clear: both;
}
#header, #about, #getting-started {
padding-left: 75px;
padding-right: 30px;
}
#header {
background-image: url("images/rails.png");
background-repeat: no-repeat;
background-position: top left;
height: 64px;
}
#header h1, #header h2 {margin: 0}
#header h2 {
color: #888;
font-weight: normal;
font-size: 16px;
}
#about h3 {
margin: 0;
margin-bottom: 10px;
font-size: 14px;
}
#about-content {
background-color: #ffd;
border: 1px solid #fc0;
margin-left: -55px;
margin-right: -10px;
}
#about-content table {
margin-top: 10px;
margin-bottom: 10px;
font-size: 11px;
border-collapse: collapse;
}
#about-content td {
padding: 10px;
padding-top: 3px;
padding-bottom: 3px;
}
#about-content td.name {color: #555}
#about-content td.value {color: #000}
#about-content ul {
padding: 0;
list-style-type: none;
}
#about-content.failure {
background-color: #fcc;
border: 1px solid #f00;
}
#about-content.failure p {
margin: 0;
padding: 10px;
}
#getting-started {
border-top: 1px solid #ccc;
margin-top: 25px;
padding-top: 15px;
}
#getting-started h1 {
margin: 0;
font-size: 20px;
}
#getting-started h2 {
margin: 0;
font-size: 14px;
font-weight: normal;
color: #333;
margin-bottom: 25px;
}
#getting-started ol {
margin-left: 0;
padding-left: 0;
}
#getting-started li {
font-size: 18px;
color: #888;
margin-bottom: 25px;
}
#getting-started li h2 {
margin: 0;
font-weight: normal;
font-size: 18px;
color: #333;
}
#getting-started li p {
color: #555;
font-size: 13px;
}
#sidebar ul {
margin-left: 0;
padding-left: 0;
}
#sidebar ul h3 {
margin-top: 25px;
font-size: 16px;
padding-bottom: 10px;
border-bottom: 1px solid #ccc;
}
#sidebar li {
list-style-type: none;
}
#sidebar ul.links li {
margin-bottom: 5px;
}
</style>
<script src="/javascripts/jquery.js" type="text/javascript"></script>
<script type="text/javascript">
function about() {
info = document.getElementById('about-content');
if (window.XMLHttpRequest)
{ xhr = new XMLHttpRequest(); }
else
{ xhr = new ActiveXObject("Microsoft.XMLHTTP"); }
xhr.open("GET","rails/info/properties",false);
xhr.send("");
info.innerHTML = xhr.responseText;
info.style.display = 'block'
}
</script>
<script type="text/javascript">
alert('Start of JSON Routine');
$(document).ready( function() {
alert('Attach a JQuery Live event to the button');
$('#getdata-button').live('click', function() {
alert("Get JSON data");
$.getJSON('http://0.0.0.0:3000/getjson/1', function(data) {
alert('Processing returned JSON data');
var tmp = '<table border=1>';
for (i=0;i<data.length;i++)
{
tmp = tmp +'<tr>';
tmp = tmp + '<td>' + data[i].book.price + '</td>';
tmp = tmp + '<td>' + data[i].book.title + '</td>';
tmp = tmp + '<td>' + data[i].book.author + '</td>';
tmp = tmp + '<td>' + data[i].book.ISBN + '</td>';
tmp = tmp + '<td>' + data[i].book.yearPublished + '</td>';
tmp = tmp + '<td>' + data[i].book.volume + '</td>';
tmp = tmp + '<td>' + data[i].book.publisher + '</td>';
tmp = tmp + '<td>' + data[i].book.edition + '</td>';
tmp = tmp + '<td><a href=# onclick=\"alert('+ i +')\">View</a></td>';
tmp = tmp + '</tr>';
}
tmp = tmp + '</table>';
alert('About to insert Table into DOM in content Div');
$('#showdata').html(tmp);
}); //getJSON end
}); //getdata-button end
}); //document.ready end
alert('End of JSON routine');
</script>
</head>
<body>
<div id="page">
<div id="sidebar">
<ul id="sidebar-items">
<li>
<h3>Browse the documentation</h3>
<ul class="links">
<li><a href="http://api.rubyonrails.org/">Rails API</a></li>
<li><a href="http://stdlib.rubyonrails.org/">Ruby standard library</a></li>
<li><a href="http://corelib.rubyonrails.org/">Ruby core</a></li>
<li><a href="http://guides.rubyonrails.org/">Rails Guides</a></li>
</ul>
</li>
</ul>
</div>
<a href="#" id="getdata-button">Get JSON Data</a>
<script>alert("Before the JMC div");</script>
<div id="showdata">JMC</div>
<script>alert("Past the JMC div");</script>
<div id="content">
<h1>Welcome aboard</h1>
<h2>You’re riding Ruby on Rails!</h2>
</div>
<div id="about">
<h3><a href="rails/info/properties" onclick="about(); return false">About your application’s environment</a></h3>
<div id="about-content" style="display: none"></div>
</div>
<div id="getting-started">
<h1>Getting started</h1>
<h2>Here’s how to get rolling:</h2>
<ol>
<li>
<h2>Use <code>rails generate</code> to create your models and controllers</h2>
<p>To see all available options, run it without parameters.</p>
</li>
<li>
<h2>Set up a default route and remove or rename this file</h2>
<p>Routes are set up in config/routes.rb.</p>
</li>
<li>
<h2>Create your database</h2>
<p>Run <code>rake db:migrate</code> to create your database. If you're not using SQLite (the default), edit <code>config/database.yml</code> with your username and password.</p>
</li>
</ol>
</div>
</div>
<div id="footer"> </div>
</div>
</body>
</html>
这是我刚从浏览器直接调用 URL/Controller 操作时返回的 JSON 数据：
[
{
"book":{
"price":"25.52",
"created_at":"2011-10-27T22:35:04Z",
"ISBN":"",
"author":"Obie Fernandez",
"title":"Rails 3 Way, The (2nd Edition)",
"updated_at":"2011-10-27T22:35:04Z",
"yearPublished":"2010",
"id":1,
"publisher":"Addison-Wesley",
"volume":"2",
"edition":"second edition"
}
},
{
"book":{
"price":"23.94",
"created_at":"2011-10-27T22:39:37Z",
"ISBN":"",
"author":"Michael Hartl",
"title":"Ruby on Rails 3 Tutorial: Learn Rails by Example",
"updated_at":"2011-10-27T22:39:37Z",
"yearPublished":"2010",
"id":2,
"publisher":"Addison-Wesley",
"volume":"",
"edition":"first edition"
}
},
{
"book":{
"price":"24.97",
"created_at":"2011-10-27T22:42:42Z",
"ISBN":"",
"author":"Cloves Carneiro Jr. and Rida Al Barazi",
"title":"Beginning Rails 3 ",
"updated_at":"2011-10-27T22:42:42Z",
"yearPublished":"2009",
"id":3,
"publisher":"Apress",
"volume":"",
"edition":"first edition"
}
}
]
任何其他可能有用的东西。 Rails 日志显示请求被正确处理。
当我单步执行脚本时，警报会按顺序出现：
我收到的第一个警报是“在 JSON 例程开始时”，然后是“完成文档准备例程”，然后是“将 JQuery Live 事件附加到按钮”。然后我单击 getdata 按钮，然后在 URL 的末尾出现一个 #，然后什么也没有。
将脚本移动到头部 - 结果相同。
将#content 切换为#showdata - 结果相同。
最终编辑：
多亏了很多人的投入，问题才得以解决。
有很多问题，但最后一个问题是同源错误，因为 getJSON 请求上的 URL 与发出请求的 URL 不同。请求有 0.0.0.0:3000/getjson/1，而请求 URL 是 localhost:3000/getjson/1。很难发现，并且 getJSON 缺少返回/状态信息使其更加困难。无论如何，感谢所有贡献者，他们都做出了有效的贡献。我希望有一天我有专业知识为自己做出贡献。
【问题讨论】：
-
@MikeStewart "数据是从控制器中检索到的 [...]"
-
你能给我们举一个你的json数据的例子吗？你有任何错误吗？究竟什么不是“工作”？
-
也许脚本标签正在替换自己，把代码放在头上试试？该脚本包含在#content
-
您在此处缺少一个分号：
alert('About to insert Table into DOM in content Div') -
您的代码有效：jsfiddle.net/gilly3/RtCaB.
标签： javascript jquery ruby-on-rails ruby-on-rails-3 json