PHPのお勉強!

PHP TOP

DOMDocument::load

(PHP 5, PHP 7, PHP 8)

DOMDocument::load ファイルから XML を読み込む

説明

public DOMDocument::load(string $filename, int $options = 0): bool

XML ドキュメントをファイルから読み込みます。

警告

Unix 風のパス (スラッシュを使った方式) を Windows 上で使用すると、 パフォーマンスが著しく低下します。そんな場合は realpath() をコールしましょう。

パラメータ

filename

XML ドキュメントへのパス。

options

libxml オプション定数ビット OR で連結したもの。

戻り値

成功した場合に true を、失敗した場合に false を返します。

エラー / 例外

空の文字列を filename に渡したり中身が空のファイルを指定したりすると、警告が発生します。 この警告は libxml が発するものではないので、libxml のエラー処理関数では処理できません。

変更履歴

バージョン 説明
8.3.0 この関数の仮の戻り値の型が、bool になりました。
8.0.0 この関数を static メソッドとしてコールすると、 Error がスローされるようになりました。 これより前のバージョンでは、 E_DEPRECATED が発生していました。

例1 ドキュメントの作成

<?php
$doc
= new DOMDocument();
$doc->load('book.xml');
echo
$doc->saveXML();
?>

参考

add a note

User Contributed Notes 14 notes

up
15
Jonas Due Vesterheden
15 years ago
I had a problem with loading documents over HTTP. I would get errors looking like this:

Warning: DOMDocument::load(http://external/document.xml): failed to open stream: HTTP request failed! HTTP/1.1 500 Internal Server Error

The document would load fine in browsers and using wget. The problem is that DOMDocument::load() on my systems (both OS X and Linux) didn't send any User-Agent header which for some weird reason made Microsoft-IIS/6.0 respond with the 500 error.

The solution is found on http://php.net/manual/en/function.libxml-set-streams-context.php :

<?php
$opts
= array(
'http' => array(
'user_agent' => 'PHP libxml agent',
)
);

$context = stream_context_create($opts);
libxml_set_streams_context($context);

// request a file through HTTP
$doc = DOMDocument::load('http://www.example.com/file.xml');
?>
up
2
hh dot lohmann at yahoo dot de
17 years ago
BadGuy´s note may be confusing since what he depicts is no special property of the relevant method. PHP works always in and on a local file system which means that if you want to use resources from other systems or - what is, indeed, BadGuy´s problem - need resources that have been dealt with by other programs or processes, you have to state and manage that explicitly in your code. PHP is just a quite normal program in that.

BadGuy´s solution is using the "http wrapper" to get output from another process (see "wrappers" in the PHP manual). Doing this, the appropriate syntax for http calls has to be respected.
up
2
admin at tijnema dot tijnema dot info
17 years ago
In reply to BadGuy [at] BadGuy [dot] nl

When the news.php file is located on the same server, like you said in the first example then http://my.beautiful-website.com/xmlsource/news.php wouldn't work, but you should use http://localhost/xmlsource/news.php or http://127.0.0.1/xmlsource/news.php
up
3
the_N_Channel
16 years ago
NOTE, will not load successfully if there is a comment at the beginning of the file before the <?xml version="1.0" ?> declaration!
up
3
BadGuy [at] BadGuy [dot] nl
17 years ago
Note that this method uses the local file system before doing anything remote. The 'disadvantage' would be that if you would do the following:
<?php
$xml
= new DOMDocument;
$xml->load("xmlsource/news.php");
?>

This would not make the method read the actual output of the news.php file --presumably valid xml data--, but the file contents --obviously this would be php code. So this will return an error saying news.php is missing the xml declaration and maybe the xml start-tag

What would work is the following:

<?php
$xml
= new DOMDocument;
$xml->load("http://my.beautiful-website.com/xmlsource/news.php");
?>

This will force a http request to be used to get this file instead of just locally reading it and the file just returning code
up
1
sainthyoga2003 at gmail dot com
12 years ago
in the default example:

<?php
$doc
= new DOMDocument();
$doc->load('book.xml');
echo
$doc->saveXML();
?>

you must enter the absolute path for book.xml due for get a false result in load function.
up
1
Raf-sns
1 year ago
Be carreful with the option "preserveWhiteSpace"

$dom = new DOMDocument;
// false -> this preserve white spaces
// true -> this will put all entries inline
$dom->preserveWhiteSpace = false; // preserve white space !
up
0
sainthyoga2003 at gmail dot com
13 years ago
i've found the partial solution for xml:id warning,is explained at this address: https://fosswiki.liip.ch/display/BLOG/GetElementById+Pitfalls

there explains that:
The ID does have to be a valid NCName, which for example means, that the first letter can't be a number.

and in my xml:id i had a number. :D
up
0
_ michael
14 years ago
XHTML and entities: The solution proposed below by zachatwork at gmail dot com didn't work for me. I checked on a number of servers (both LAMPP and WAMPP) - on each of them, calling loadXML() with the LIBXML_DTDLOAD option triggered an external request for the DTD. And that's bad news.

If allow_url_fopen is turned off, the request for the DTD fails with a warning. If it is turned on, the request fails because these w3c URLs return a 503 Service Unavailable.

HTML entities still generate a warning in either case.

The best solution, as far as I can tell, is simply to ignore the warnings and suppress them using '@'. I can't recommend parsing XHTML with loadHTML() instead of loadXML() - yes, you get rid of the entity problem, but loadHTML() changes the source while parsing it (tries to 'fix' it even though there is nothing to fix).
up
0
syntaxiko
15 years ago
Function will not work if using XML DOM PECL module
up
-2
daevid at daevid dot com
19 years ago
Suppose you wanted to dynamically load an array from an .XSD file. This method is your guy. just remember to use the actual xs: portion in xpaths and such.

All the other "load" methods will error out.

<?php
$attributes
= array();
$xsdstring = "/htdocs/api/xsd/common.xsd";
$XSDDOC = new DOMDocument();
$XSDDOC->preserveWhiteSpace = false;
if (
$XSDDOC->load($xsdstring))
{
$xsdpath = new DOMXPath($XSDDOC);
$attributeNodes =
$xsdpath->
query('//xs:simpleType[@name="attributeType"]')
->
item(0);
foreach (
$attributeNodes->childNodes as $attr)
{
$attributes[ $attr->getAttribute('value') ] = $attr->getAttribute('name');
}
unset(
$xsdpath);
}
print_r($attributes);
?>
up
-2
_ michael
14 years ago
load() will handle non-ASCII characters depending on the details of the XML declaration, but in a somewhat surprising way. One would assume that the declarations '<?xml version="1.0" encoding="UTF-8"?>' and '<?xml version="1.0"?>' are treated in the same way because UTF-8 is the default encoding anyway. But not so.

* If there is an XML declaration defining the encoding *explicitly*, the non-ASCII characters remain unchanged.
* If the XML declaration does not define the encoding explicitly, or if the XML declaration is missing, non-ASCII characters are converted into numeric entities.

So the document

<?xml version="1.0"?>
<root><nonascii>ä</nonascii></root>

will be converted to

<?xml version="1.0"?>
<root><nonascii>&#xE4;</nonascii></root>

The same happens if there is no XML declaration at all. On the other hand, the document

<?xml version="1.0" encoding="UTF-8"?>
<root><nonascii>ä</nonascii></root>

will remain as it is.

This behaviour applies to loadXML() as well.
up
-2
darren at viamedia dot co dot za
16 years ago
If you are loading xml with the intention of validating it against an internal dtd and you have experienced issues with the validation it could be related to missing LIBXML constants.

I found this post by "aidan at php dot net" in root level dom docs and thought it might be more useful here:
As of PHP 5.1, libxml options may be set using constants rather than the use of proprietary DomDocument properties.

DomDocument->resolveExternals is equivilant to setting
LIBXML_DTDLOAD
LIBXML_DTDATTR

DomDocument->validateOnParse is equivilant to setting
LIBXML_DTDLOAD
LIBXML_DTDVALID

PHP 5.1 users are encouraged to use the new constants.

Example:
<?php
$dom
= new DOMDocument;
// Resolve externals
$dom->load($file, LIBXML_DTDLOAD|LIBXML_DTDATTR);
// OR
// Validate against DTD
$dom->load($file, LIBXML_DTDLOAD|LIBXML_DTDVALID);
$dom->validate();
?>
up
-2
zachatwork at gmail dot com
15 years ago
You can easily avoid the warning about &nbsp; references by using the LIBXML_DTDLOAD option.

<?php

$html
= <<<EOF
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
</head>
<body>
<p>&nbsp;</p>
</body>
</html>
EOF;

// This one works perfectly.
$dom = new DOMDocument();
$dom->loadXML($html, LIBXML_DTDLOAD);
print
$dom->saveXML();

// This one produces a warning.
$dom = new DOMDocument();
$dom->loadXML($html);
print
$dom->saveXML();

?>

See also: http://www.php.net/manual/en/libxml.constants.php

Note that libxml will detect that your DTD is locally available via /etc/xml/catalog. So there is no worry about this causing your DOM loads to make external network requests.