SimpleXMLElement
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SimpleXMLElement::__construct

(PHP 5 >= 5.0.1)

SimpleXMLElement::__construct — Creates a new SimpleXMLElement object

说明

final public SimpleXMLElement::__construct() ( string $data [, int $options = 0 [, bool $data_is_url = false [, string $ns = "" [, bool $is_prefix = false ]]]] )

Creates a new SimpleXMLElement object.

参数

data

A well-formed XML string or the path or URL to an XML document if data_is_url is TRUE.

options

Optionally used to specify additional Libxml parameters.

data_is_url

By default, data_is_url is FALSE. Use TRUE to specify that data is a path or URL to an XML document instead of string data.

ns

Namespace prefix or URI.

is_prefix

TRUE if ns is a prefix, FALSE if it's a URI; defaults to FALSE.

返回值

Returns a SimpleXMLElement object representing data.

错误/异常

Produces an E_WARNING error message for each error found in the XML data and additionally throws an Exception if the XML data could not be parsed.

Tip

Use libxml_use_internal_errors() to suppress all XML errors, and libxml_get_errors() to iterate over them afterwards.

范例

Note:

Listed examples may include example.php, which refers to the XML string found in the first example of the basic usage guide.

Example #1 Create a SimpleXMLElement object

<?php

include 'example.php';

$sxe = new SimpleXMLElement($xmlstr);
echo $sxe->movie[0]->title;

?>

以上例程会输出：

PHP: Behind the Parser

Example #2 Create a SimpleXMLElement object from a URL

<?php

$sxe = new SimpleXMLElement('http://example.org/document.xml', NULL, TRUE);
echo $sxe->asXML();

?>

参见

SimpleXMLElement
在线手册：中文 英文
PHP手册
PHP手册 - N: Creates a new SimpleXMLElement object

用户评论:

kumarldh at gmail dot com (23-Mar-2011 06:50)

Using libxml_use_internal_errors() may suppress errors but Exception still requires decent handling. I used following code snippet.

<?php
libxml_use_internal_errors(true);
try{
    $xmlToObject = new SimpleXMLElement($notSoWellFormedXML);
} catch (Exception $e){
    echo 'Please try again later...';
    exit();
}
?>

zwilson at gulosolutions dot com (19-Nov-2009 06:16)

SimpleXML does not correctly parse SOAP XML results if the result comes back with colons ‘:’ in a tag, like <soap:Envelope>. Why? Because SimpleXML treats the colon character ‘:’ as an XML namespace, and places the entire contents of the SOAP XML result inside a namespace within the SimpleXML object. There is no real way to correct this using SimpleXML, but we can alter the raw XML result a little before we send it to SimpleXML to parse.

All we have to do is use the preg_replace function to get rid of the colons in the SOAP response tags BEFORE you hand it off to SimpleXML, like so:

<?php
// SimpleXML seems to have problems with the colon ":" in the <xxx:yyy> response tags, so take them out
$xmlString = preg_replace("/(<\/?)(\w+):([^>]*>)/", "$1$2$3", $response);
?>

uramihsayibok, gmail, com (17-Aug-2009 02:52)

As I was filling out a bug report, I realized why (speculation here) the constructor is final: so that functions like simplexml_load_file and simplexml_load_string can work. I imagine the PHP-ized code looks something like

<?php

function simplexml_load_file($filename, $class_name = "SimpleXMLElement", $options = 0, $ns = "", $is_prefix = false) {
    return new $class_name($filename, $options, true, $ns, $is_prefix);
}

?>

If we were to use a different $class_name and change the constructor's definition these functions wouldn't work.

There's no easy, sensible solution that keeps simplexml_load_file and simplexml_load_string.

tudor at culise dot net (20-Nov-2007 11:35)

This class is extendable, but it's too bad that its constructor cannot be overriden (PHP says it's a final method). Thus the class should be wrapped using the delegation principle rather that extended.