SimpleXML 返回多个对象,如何获取数据? [英] SimpleXML returning multiple objects, how can I get the data?
问题描述
我使用 simpleXML 解析 这个 xml 文件.这是我用来访问 YouTube API 的提要.我想在一个对象中嵌入最新的视频并显示接下来的四个缩略图.
I'm using simpleXML to parse this xml file. It's a feed I'm using to access the YouTube API. I want to embed the most recent video in an object and display the next four thumbnails.
所以我在这方面使用 simplexml_load_file
,使用 foreach
循环访问每个提要中的值.
So I'm using simplexml_load_file
on this, going using a foreach
loop to access the values in each feed.
我可以毫无问题地访问这些值,但我遇到了将每个视频存储在单独的 SimpleXMLElement 对象
中的问题.我无法控制我正在访问的对象,因为它们没有存储在数组中.所以我无法得到,比如 $thumb[4]
或 $entry[4]->thumb
.
I can access the values no problem, but I run into the problem that it stores each video in a separate SimpleXMLElement Object
. I don't have any control over which object I'm accessing as they are not stored in an array. So I can't get, say, $thumb[4]
or $entry[4]->thumb
.
我尝试使用 SimpleXMLIterator
,但无论出于何种原因,任何具有相同开头的值都呈现为空白.例如,视频可以有十一种变体:
I tried to use SimpleXMLIterator
, but for whatever reason, any values that have the same beginning render as blank. For example, the video could have eleven variations of:
这些都将呈现为 [1]=""
, [2]=""
, [3]=""
等
And these would each render as [1]=""
, [2]=""
, [3]=""
, etc.
我很乐意为任何可以提供帮助的人提供更多信息!
I'll happily provide some more information to anyone who can help!
编辑
这是我的结果的 print_r.这是在单个变量上完成的,目的是让您了解我面临的结构问题.整个 print_r($entry) 将为 XML 文件中的每个节点提供变量.
Here is the print_r of my results. This is done on a single variable to give you an idea of the structure issue I'm facing. The entire print_r($entry) would give variables for each node in the XML file.
SimpleXMLElement Object
(
[0] => 159
)
SimpleXMLElement Object
(
[0] => 44
)
此外,print_r 只是在 PHP 块中进行测试.我实际上是想访问 HTML 中回声中的变量.
Also, the print_r is simply inside the PHP block for testing. I'm actually looking to access the variables within echoes in the HTML.
推荐答案
你遇到了命名空间和 SimpleXML.提要以
<feed xmlns='http://www.w3.org/2005/Atom' xmlns:media='http://search.yahoo.com/mrss/' xmlns:openSearch='http://a9.com/-/spec/opensearchrss/1.0/' xmlns:gd='http://schemas.google.com/g/2005' xmlns:yt='http://gdata.youtube.com/schemas/2007'>
xmlns='http://www.w3.org/2005/Atom'
将默认命名空间设置为 http://www.w3.org/2005/Atom代码>.IE.它的子元素并不是真正的
id
、updated
、category
,而是 http://www.w3.org/2005/Atom:id
、http://www.w3.org/2005/Atom:updated
等等...
所以你不能通过$feed->id
访问id元素,你需要方法SimpleXMLELement::children().它允许您指定要检索的子元素的命名空间.
The xmlns='http://www.w3.org/2005/Atom'
sets the default namespace to http://www.w3.org/2005/Atom
. I.e. its child elements are not really id
, updated
, category
but http://www.w3.org/2005/Atom:id
, http://www.w3.org/2005/Atom:updated
and so on...
So you can't access the the id element via $feed->id
, you need the method SimpleXMLELement::children(). It lets you specify the namespace of the child elements you want to retrieve.
例如
$feed = simplexml_load_file('http://gdata.youtube.com/feeds/api/videos?author=ofcoursegolf&max-results=5&prettyprint=true');
$children = $feed->children('http://www.w3.org/2005/Atom');
echo $children->updated;
当前打印 2010-02-06T05:23:33.858Z
.
要获取第一个条目元素的 id,您可以使用 echo $children->entry[0]->id;
.
但是随后您将点击
元素及其子元素
等等...,它们位于 xmlns:media='http://search.yahoo.com/mrss/'
命名空间中.
To get the id of the first entry element you can use echo $children->entry[0]->id;
.
But then you'll hit the <media:group>
element and its children <media:category
, <media:player>
and so on..., which are in the xmlns:media='http://search.yahoo.com/mrss/'
namespace.
$feed = simplexml_load_file('http://gdata.youtube.com/feeds/api/videos?author=ofcoursegolf&max-results=5&prettyprint=true');
$group = $feed->children('http://www.w3.org/2005/Atom')
->entry[0]
->children('http://search.yahoo.com/mrss/')
->group
->children('http://search.yahoo.com/mrss/')
;
echo $group->player->attributes()->url, "\n";
foreach( $group->thumbnail as $thumb) {
echo 'thumb: ', $thumb->attributes()->url, "\n";
}
(当前)打印
http://www.youtube.com/watch?v=ikACkCpJ-js&feature=youtube_gdata
thumb: http://i.ytimg.com/vi/ikACkCpJ-js/2.jpg
thumb: http://i.ytimg.com/vi/ikACkCpJ-js/1.jpg
thumb: http://i.ytimg.com/vi/ikACkCpJ-js/3.jpg
thumb: http://i.ytimg.com/vi/ikACkCpJ-js/0.jpg
我可能会在浏览器中使用更多 JavaScript 来完成此操作,但这里有一个(简单、丑陋的)示例应用.
I'd probably do that within the browser with a lot more JavaScript, but here's a (simple, ugly) example app.
<?php
//define('TESTENV' , true);
function getFeed($author) {
// <-- add caching here if needed -->
if ( !defined('TESTENV') ) {
$url = sprintf('http://gdata.youtube.com/feeds/api/videos?author=%s&max-results=5',
urlencode($author)
);
}
else {
$url = 'feed.xml';
}
return simplexml_load_file($url);
}
$feed = getFeed('jonlajoie');
if ( !isset($_GET['id']) ) {
$selected = '';
}
else {
$selected = $_GET['id'];
printf ('
<object width="425" height="344">
<param name="movie" value="http://www.youtube.com/v/%s"></param>
<param name="allowFullScreen" value="true"></param>
<param name="allowscriptaccess" value="always">
</param>
<embed src="http://www.youtube.com/v/%s" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed>
</object>',
htmlspcialchars($selected), htmlspcialchars($selected)
);
}
$item = 0;
foreach( $feed->children('http://www.w3.org/2005/Atom')->entry as $entry ) {
$entryElements = $entry->children('http://www.w3.org/2005/Atom');
$groupElements = $entry
->children('http://search.yahoo.com/mrss/')
->group
->children('http://search.yahoo.com/mrss/')
;
if ( !preg_match('!^http://gdata.youtube.com/feeds/api/videos/([^/]+)!', $entryElements->id, $m) ) {
// google can choose whatever id they want. But this is only a simple example....
die('unexpected id: '.htmlspecialchars($entryElements->id));
}
$id = $m[1];
if ( $selected!==$id ) {
printf('<a href="?id=%s"><img src="%s" /></a>',
urlencode($id),
$groupElements->thumbnail[0]->attributes()->url
);
}
}
编辑 2:当我单击缩略图时,我将使用 jQuery 在主空间中加载视频.似乎我需要精确访问节点 [#],对吗?"
如果您已经在使用 JavaScript/jQuery,您的 PHP 脚本(如果需要的话)可以简单地返回所有视频的所有数据的(JSON 编码)数组,并且您的 jQuery 脚本可以弄清楚如何处理数据.
Edit 2: "And when I click the thumbnails, I'll use jQuery to load the video in the main space. Seems like I'll need precise access to node[#], right?"
If you're already using JavaScript/jQuery your PHP script (if needed at all) could simply return a (JSON encoded) array of all the data for all the video and your jQuery script could figure out what to do with the data.
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