SimpleXMLElement
在线手册：中文 英文
PHP手册

SimpleXMLElement::attributes

(PHP 5 >= 5.0.1)

SimpleXMLElement::attributes — Identifies an element's attributes

说明

public SimpleXMLElement SimpleXMLElement::attributes ([ string $ns = NULL [, bool $is_prefix = false ]] )

This function provides the attributes and values defined within an xml tag.

Note: SimpleXML 建起了一个给大多数方法添加迭代属性的规则。不能通过使用 var_dump() 或任何可检查对象的其它东西来查看。

参数

ns

An optional namespace for the retrieved attributes

is_prefix

Default to FALSE

返回值

Returns a SimpleXMLElement object that can be iterated over to loop through the attributes on the tag.

Returns NULL if called on a SimpleXMLElement object that already represents an attribute and not a tag.

范例

Example #1 Interpret an XML string

<?php
$string = <<<XML
<a>
 <foo name="one" game="lonely">1</foo>
</a>
XML;

$xml = simplexml_load_string($string);
foreach($xml->foo[0]->attributes() as $a => $b) {
    echo $a,'="',$b,"\"\n";
}
?>

以上例程会输出：

name="one"
game="lonely"

参见

SimpleXMLElement
在线手册：中文 英文
PHP手册
PHP手册 - N: Identifies an element's attributes

用户评论:

chris at chlab dot ch (23-Mar-2012 06:16)

Note that you must provide the namespace if you want to access an attribute of a non-default namespace:

Consider the following example:

<?php
$xml = <<<XML
<?xml version="1.0"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet">
 <Table Foo="Bar" ss:ExpandedColumnCount="7">
 </Table>
</Workbook>
XML;

$sxml = new SimpleXMLElement($xml);

/**
 * Access attribute of default namespace
 */
var_dump((string) $sxml->Table[0]['Foo']);
// outputs: 'Bar'

/**
 * Access attribute of non-default namespace
 */
var_dump((int) $sxml->Table[0]['ExpandedColumnCount']);
// outputs: 0

var_dump((int) $sxml->Table[0]->attributes('ss', TRUE)->ExpandedColumnCount);
// outputs: '7'
?>

Andrei (17-May-2011 12:46)

Reading the attributes of the root element with name space prefixes as in an Atom feed

<feed xmlns="http://www.w3.org/2005/Atom" xmlns:openSearch="http://a9.com/-/spec/opensearch/1.1/" xmlns:gd="http://schemas.google.com/g/2005" gd:etag="W/&quot;Ck4EQXYzeCp7ImA9WhZWFE4.&quot;">

<?php
$xml =  @simplexml_load_file($feed);
$att_gd = $xml->attributes("gd",1);
$Etag = $att_gd["etag"];
?>

sarlak (27-Apr-2011 09:12)

<?php
$att = 'attribueName';

// You can access an element's attribute just like this :
$attribute = $element->attributes()->$att;

// This will save the value of the attribute, and not the objet
$attribute = (string)$element->attributes()->$att;

// You also can edit it this way :
$element->attributes()->$att = 'New value of the attribute';
?>

leap (02-Apr-2011 05:07)

If you want to save the value of an attribute into an array, typecast it to a string.

<?php
// stores an xml-element-object
$dataStore['value'] = $attributes->myValue

// stores the value of the attribute
$dataStore['value'] = (string)$attributes->myValue
?>

alan at performantsystems dot com (24-May-2010 06:26)

So lets say you have database type data in an XML string called $xmlstring with the key or item ID as an XML Attribute and all content data as regular XML Elements, as above. SimpleXML processes the Attributes as an array, so we can play along and push the Attributes into an array. Then we can get the value of any specific Attribute we want by addressing it by name, such as "ID".

Considering this data:

<?xml version="1.0" encoding="utf-8"?>
<data>
   <item ID="30001">
      <Company>Navarro Corp.</Company>
   </item>
   <item ID="30002">
      <Company>Performant Systems</Company>
   </item>
   <item ID="30003">
      <Company>Digital Showcase</Company>
   </item>
</data>

Example of listing both the ID Attribute and Company Element values:
 
<?php
$xmlObject = new SimpleXMLElement($xmlstring);
foreach ($xmlObject->children() as $node) {
        $arr = $node->attributes();   // returns an array
        print ("ID=".$arr["ID"]);     // get the value of this attribute
        print ("  Company=".$node->Company);
        print ("<p><hr>");
}
?>

Xeoncross (11-Apr-2010 03:46)

It is really simple to access attributes using array form. However, you must convert them to strings or ints if you plan on passing the values to functions.

<?php
SimpleXMLElement Object
(
    [@attributes] => Array
        (
            [id] => 55555
        )

    [text] => "hello world"
)
?>

Then using a function

<?php
function xml_attribute($object, $attribute)
{
    if(isset($object[$attribute]))
        return (string) $object[$attribute];
}
?>

I can get the "id" like this

<?php
print xml_attribute($xml, 'id'); //prints "55555"
?>

gillllberg at gmail dot com (04-Nov-2009 10:21)

To get an attribute in the node, use node->attributes()->attributeName

skerr at mojavi dot org (10-Dec-2004 06:55)

You can also access the node as an array to get attributes:

<?php

$xml = simplexml_load_file('file.xml');

echo 'Attribute: ' . $xml['attribute'];

?>

inge at elektronaut dot no (26-May-2004 06:53)

here's a simple function to get an attribute by name, based on the example

<?php
function findAttribute($object, $attribute) {
  foreach($object->attributes() as $a => $b) {
    if ($a == $attribute) {
      $return = $b;
    }
  }
  if($return) {
    return $return;
  }
}
?>