php 删除 simplexmlelement 节点
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9643116/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Deleting simplexmlelement node
提问by user823527
I have an xml file of this structure
我有一个这种结构的xml文件
<?xml version="1.0" encoding="iso-8859-1"?>
<my_events>
<event id="e20111129215359">
<title>the title</title>
<channel id="1">
<name>A name</name>
<onclick></onclick>
</channel>
<event_site>
<name/>
<url/>
</event_site>
<start_date>Thu Mar 08 2012</start_date>
<start_time>11:00 AM</start_time>
<end_date>null</end_date>
<end_time>null</end_time>
<notes>Notes for the event</notes>
</event>
</my_events>
To delete an event, I have this php function.
要删除一个事件，我有这个 php 函数。
<?php
include_once("phpshared.php");
function delete_event( $nodeid ) {
$nodes = new SimpleXMLElement('my_events.xml', LIBXML_NOCDATA, true);
$node = $nodes->xpath("/my_events/event[@id='$nodeid']");
$node->parentNode->removeChild($node);
$formatted = formatXmlString($nodes->asXML());
$file = fopen ('my_events.xml', "w");
fwrite($file, $formatted);
fclose ($file);
}
echo delete_event(trim($_REQUEST['nodeid']));
?>
That doesn't delete the node. Is there a different way to do this?
这不会删除节点。有没有不同的方法来做到这一点？
回答by salathe
SimpleXML allows removal of elements via PHP's unset()keyword.
SimpleXML 允许通过 PHP 的unset()关键字删除元素。
For your code snippet, simply replace
对于您的代码片段，只需替换
$node->parentNode->removeChild($node);
with
和
if ( ! empty($node)) {
unset($node[0][0]);
}
If the XPath query returned a matching <event>element, we instruct SimpleXML to unset()it.
如果 XPath 查询返回匹配的<event>元素，我们unset()会将SimpleXML 指示给它。
Aside:here are two occurrences of [0]because:
旁白：这里有两种情况，[0]因为：
xpath()returns an array, even if only one element matches. So[0]is used to get the first item in that array, which is the element we want to delete.- The SimpleXMLElement returned from
$node[0]represents a collection of<event>elements (but if you access elements/attributes on it then the values from the first in the collection is used). So, we use[0]to get at the actualSimpleXMLElementthat we want to delete, which is the first in this magical collection.
xpath()返回一个数组，即使只有一个元素匹配。So[0]用于获取该数组中的第一项，即我们要删除的元素。- 返回的 SimpleXMLElement
$node[0]表示<event>元素集合（但如果您访问其上的元素/属性，则使用集合中第一个的值）。所以，我们使用[0]来获取SimpleXMLElement我们想要删除的实际值，这是这个神奇集合中的第一个。
