PHP操作XML方法之SimpleXML
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摘录时间：
2020-11-27 16:19:30
SimpleXML简介
SimpleXML 扩展提供了一个非常简单和易于使用的工具集，能将XML转换成一个带有一般属性选择器和数组迭代器的对象。
举例XML
XML结构部分引用自<<深入理解PHP>>，并且为了说明某个方法的使用，强行增加一些看似根本用不合理的结构
我将用该XML结构完成:
<?xml version="1.0" encoding="utf-8"?>
<collection xmlns:lan="language">
<php:book xmlns:php="php">
<php:title php:edition="3">PHP Advanced and Object-Oriented Programming: Visual QuickPro Guide</php:title>
<author:author xmlns:author="LarryUllman">Larry Ullman</author:author>
<php:year>2012</php:year>
<php:pages>612</php:pages>
<php:chapterArr>
<php:chapter php:number="12">PHP's Command-Line Interface</php:chapter>
<php:chapter php:number="13">XML and PHP</php:chapter>
<php:chapter php:number="14">Debugging, Testing, and Performance</php:chapter>
</php:chapterArr>
<php:cover php:fileName="phpvqp3.jpg"/>
</php:book>
<js:book xmlns:js="javascript">
<js:title>Modern JavaScript: Develop and Design</js:title>
<author:author xmlns:author="LarryUllman">Larry Ullman</author:author>
<js:year>2012</js:year>
<js:pages>504</js:pages>
<js:chapterArr>
<js:chapter js:number="1" js:pages="24">(Re-)Introducing JavaScript</js:chapter>
<js:chapter js:number="2" js:pages="32">JavaScript in Action</js:chapter>
<js:chapter js:number="3" js:pages="34">Tools of the Trade</js:chapter>
</js:chapterArr>
</js:book>
</collection>
类方法及函数
在实际操作(增，删，改，查)XML前，先简单介绍一下SimpleXML包含的方法和函数对应的功能，如果你对此有一定的了解,可以跳本部分，直接看：生成XML操作，读取XML操作，更新XML操作，删除XML操作的例子。
** PS:本文不会对方法和函数的功能及参数做详细介绍（因为都已尽量体现在操作中），如想了解更多，请参考官网。 **
方法
- addAttribute 为SimpleXML元素添加一个属性
- addChild 为SimpleXML节点增加一个子节点
- asXML 返回一个基于SimpleXML对象没有语法错误的XML字符串
- attributes 识别元素的的所有属性
- children 返回给定节点的子节点
- __construct 创建SimpleXML对象的初始化方法
- count 计算元素子节点个数
- getDocNamespaces 获取XML文档中申明的命名空间
- getName 获取SimpleXML节点的元素名
- getNamespaces 获取XML文档中使用过的命名空间
- registerXPathNamespace 为XPath查询创建一个前缀或者命名空间
- saveXML asXML的别名
- __toString 魔术方法，返回SimpleXML节点的字符串内容
- xpath 运行一个xpath查询
函数
- simplexml_import_dom 把一个DOM对象转换为一个SimpleXML对象
- simplexml_load_file 把一个XML文件解析为一个SimpleXML对象
- simplexml_load_string 把一个字符串解析为一个SimpleXML对象
SimpleXML操作XML
生成XML
<?php
//定义数据
$bookArr = [
[
'book' => [
'value' => null,
'attr' => [
'nsKey' => 'program:xmlns:php',
'nsVal' => 'php',
],
],
'title' =>
[
'value' => 'PHP Advanced and Object-Oriented Programming: Visual QuickPro Guide',
'attr' => [
'edition' => 3
]
],
'author' => 'Larry Ullman',
'year' => 2012,
'pages' => 612,
'chapterArr'=>
[
[
'value' => 'PHP's Command-Line Interface',
'attr' => ['number'=>12]
],
[
'value' => 'XML and PHP',
'attr' => ['number'=>13]
],
[
'value' => 'Debugging, Testing, and Performance',
'attr' => ['number'=>14]
],
],
'cover' => [
'attr' => ['fileName'=>'phpvqp3.jpg'],
]
],
[
'book' => [
'value' => null,
'attr' => [
'nsKey' => 'program:xmlns:js',
'nsVal' => 'javascript',
]
],
'title' => ['value'=>'Modern JavaScript: Develop and Design'],
'author' => 'Larry Ullman',
'year' => 2012,
'pages' => 504,
'chapterArr'=> [
[
'value' => '(Re-)Introducing JavaScript',
'attr' => ['number'=>1, 'pages'=>24]
],
[
'value' => 'JavaScript in Action',
'attr' => [ 'number'=>2, 'pages'=>32]
],
[
'value' => 'Tools of the Trade',
'attr' => ['number'=>3,'pages'=>34]
]
]
]
];
//用一段字符串生成一个XML的root节点
$statement = '<?xml version="1.0" encoding="utf-8"?><collection xmlns:lan="language"></collection>';
$rootXML = simplexml_load_string($statement); //等价于 $rootXML = new SimpleXMLElement($statement);
foreach($bookArr as $book){
//获取数组中定义的节点的命名空间，如program:xmlns:php，则php为元素的前缀
$tempPrefix = substr($book['book']['attr']['nsKey'],strpos($book['book']['attr']['nsKey'], ':') + 1);
$prefix = $tempPrefix ? $tempPrefix . ':' : '';
//为root节点添加一个带有指定命名空间的book节点
$bookNode = $rootXML->addChild($prefix.'book',$book['book']['value']);
//定义book节点的命名空间及前缀
$bookNode->addAttribute($book['book']['attr']['nsKey'],$book['book']['attr']['nsVal']);
//为book节点添加一个带有指定命名空间，指定值的title节点
$titleNode = $bookNode->addChild($prefix.'title',$book['title']['value']);
//为title节点增加指定命名空间及属性
if(!empty($book['title']['attr'])){
foreach($book['title']['attr'] as $k => $v){
$titleNode->addAttribute($prefix.$k,$v);
}
}
//为book节点添加一个子节点author及值
$authorNode = $bookNode->addChild('author',$book['author']);
//为author节点设置命名空间及前缀
$authorNode->addAttribute('program:xmlns:author','LarryUllman');
//为book节点添加一个子节点year及值
$bookNode->addChild($prefix.'year',$book['year']);
//为book节点添加一个子节点pages及值
$bookNode->addChild($prefix.'pages',$book['pages']);
//为book节点增加一个指定命名空间的chapterArr节点
$chapterArr = $bookNode->addChild($prefix.'chapterArr');
//为chapterArr节点增加一个指定命名空间，指定值指定属性的chapter节点
if(!empty($book['chapterArr'])){
foreach($book['chapterArr'] as $value){
$chapterNode = $chapterArr->addChild($prefix.'chapter',$value['value']);
if(!empty($value['attr'])) {
foreach ($value['attr'] as $k => $v) {
$chapterNode->addAttribute($prefix . $k, $v);
}
}
}
}
//为book节点增加一个子节点带有指定命名空间的cover，并设置其属性
if(!empty($book['cover']['attr']['fileName'])){
$coverNode = $bookNode->addChild($prefix.'cover',null);
$coverNode->addAttribute($prefix.'fileName',$book['cover']['attr']['fileName']);
}
}
//设置header头
header('content-type:text/xml;');
//格式化输出SimpleXML对象
$xmlStr = $rootXML->asXML(); //也可保存到文件 $rootXML->asXML('/path/to/filename.xml');
echo $xmlStr;
读取XML
//给定XML
$xmlStr = <<<XML
<?xml version="1.0" encoding="utf-8"?>
<collection xmlns:lan="language">
<php:book xmlns:php="php">
<php:title php:edition="3">PHP Advanced and Object-Oriented Programming: Visual QuickPro Guide</php:title>
<author:author xmlns:author="LarryUllman">Larry Ullman</author:author>
<php:year>2012</php:year>
<php:pages>612</php:pages>
<php:chapterArr>
<php:chapter php:number="12">PHP's Command-Line Interface</php:chapter>
<php:chapter php:number="13">XML and PHP</php:chapter>
<php:chapter php:number="14">Debugging, Testing, and Performance</php:chapter>
</php:chapterArr>
<php:cover php:fileName="phpvqp3.jpg"/>
</php:book>
<js:book xmlns:js="javascript">
<js:title>Modern JavaScript: Develop and Design</js:title>
<author:author xmlns:author="LarryUllman">Larry Ullman</author:author>
<js:year>2012</js:year>
<js:pages>504</js:pages>
<js:chapterArr>
<js:chapter js:number="1" js:pages="24">(Re-)Introducing JavaScript</js:chapter>
<js:chapter js:number="2" js:pages="32">XML and PHP</js:chapter>
<js:chapter js:number="3" js:pages="34">Debugging, Testing, and Performance</js:chapter>
</js:chapterArr>
</js:book>
</collection>
XML;
$rootXML = simplexml_load_string($xmlStr,null,null,'js',true);////等价于 $rootXML = new SimpleXMLElement($xmlStr,null,false,'js',true);
$data = [];
foreach($rootXML->book as $book){
$data[$key]['title'] = (string)$book->title; //title值
$data[$key]['edition'] = (string)$book->title['edition'];//title的edition属性值
//获取book节点下命名空间前缀为author的子节点
$author = $book->children('author',true);//
$data[$key]['author'] = (string)$author;//author值
$data[$key]['year'] = (int)$book->year;//year值
$data[$key]['pages'] = (int)$book->pages;//pages值
//多种获取属性的方式 开始
$i = 0;
foreach($book->chapterArr[0] as $chapter) {
$data[$key]['chapterArr'][$i]['value'] = (string)$chapter;//chapter值
//获取chapter节点的number，pages属性
foreach ($chapter->attributes('js', true) as $chapterKey => $chapterVal) {
$data[$key]['chapterArr'][$i]['attr'][$chapterKey] = (int)$chapterVal;
}
//$data[$key]['chapterArr'][$i]['attr']['number'] = (int)$chapter['number'];//也可这么获取number属性
//$data[$key]['chapterArr'][$i]['attr']['pages'] = (int)$chapter['pages'];//也可这么获取pages属性
$i++;
}
/*
//获取chapterArr子节点个数，然后循环获取值及属性
$chapterNum = $book->chapterArr[0]->count();
for($i=0;$i<$chapterNum;$i++) {
$data[$key]['chapterArr'][$i]['value'] = (string)$book->chapterArr->chapter[$i];chapter值
$data[$key]['chapterArr'][$i]['attr']['number'] = (int)$book->chapterArr->chapter[$i]['number'];number属性
$data[$key]['chapterArr'][$i]['attr']['pages'] = (int)$book->chapterArr->chapter[$i]['pages'];pages属性
}
*/
/*
通过xpath获取属性
$chapterArr = $bookNode->xpath('//js:book//js:chapterArr//js:chapter');
$i=0;
foreach($chapterArr as $k=>$v){
$data[$key]['chapterArr'][$i]['value'] = (string)$v;
foreach($attr = $v->attributes('js',true) as $k=>$v){
$data[$key]['chapterArr'][$i]['attr'][$k] = (int)$v;
}
$i++;
}
*/
//多种获取属性的方式 结束
//cover值
$fileName = (string)($book->cover['fileName']) && $data[$key]['cover']['attr']['fileName'] = $fileName;
}
var_dump($data);die;
更新XML
//$xmlStr如上
$rootXML = simplexml_load_string($xmlStr,null,null,'js',true);////等价于 $rootXML = new SimpleXMLElement($xmlStr,null,false,'js',true);
//更新标题及chapter的值及属性
$rootXML->book->title = 'modifyXML';
$chapterArrNode = $rootXML->book->chapterArr[0];
$i = 1;
foreach($chapterArrNode as $chapter){
$chapter[0] = 'chapter'.$i;//修改值
$chapter['number'] = 'number'.$i;//修改number属性
$chapter['pages'] = 'pages'.$i;//修改pages属性
$i++;
}
//设置header头
header('content-type:text/xml;');
//格式化输出SimpleXML对象
$xmlStr = $rootXML->asXML(); //也可保存到文件 $rootXML->asXML('/path/to/filename.xml');
echo $xmlStr;
删除XML
//$xmlStr如上
$rootXML = simplexml_load_string($xmlStr,null,null,'js',true);////等价于 $rootXML = new SimpleXMLElement($xmlStr,null,false,'js',true);
//删除year
unset($rootXML->book->year);
//删除最后chapter标签
unset($rootXML->book->chapterArr[0]->chapter[2]);
//删除第一个chapter的pages属性
unset($rootXML->book->chapterArr[0]->chapter[0]['pages']);
//使用xpath删除number为2的chapter标签
$rootXML->registerXPathNamespace('js','javascript');
foreach($rootXML->xpath('//js:book//js:chapterArr//js:chapter[@js:number=2]') as $chapter2)
{
unset($chapter2[0]);
}
//设置header头
header('content-type:text/xml;');
$xmlStr = $rootXML->asXML(); //也可保存到文件 $rootXML->asXML('/path/to/filename.xml');
echo $xmlStr;
