DOMDocument::loadHTMLFile()

(PHP 5, PHP 7)

Load HTML from a file

说明

publicDOMDocument::loadHTMLFile(string $filename[,int $options= 0]): bool

The function parses the HTML document in the file named$filename. Unlike loading XML, HTML does not have to be well-formed to load.

参数

$filename: The path to the HTML file.
$options: Since PHP 5.4.0 and Libxml 2.6.0, you may also use the$optionsparameter to specify additional Libxml parameters.

返回值

成功时返回TRUE，或者在失败时返回FALSE。 If called statically, returns a DOMDocument或者在失败时返回FALSE.

错误／异常

If an empty string is passed as the$filenameor an empty file is named, a warning will be generated. This warning is not generated by libxml and cannot be handled using libxml's error handling functions.

此方法可以被静态调用,但会抛出一个E_STRICT错误。

尽管非正确格式化的 HTML 仍应该被成功调入，但此函数会在遇到错误标记时产生E_WARNING错误。libxml 错误处理函数可以用来处理这类错误。

范例

Example #1 Creating a Document

<?php
$doc = new DOMDocument();
$doc->loadHTMLFile("filename");
echo $doc->saveHTML();
?>

更新日志

版本	说明
5.4.0	Added`$options`parameter.

参见

DOMDocument::loadHTML() Load HTML from a string
DOMDocument::saveHTML() Dumps the internal document into a string using HTML formatting
DOMDocument::saveHTMLFile() Dumps the internal document into a file using HTML formatting

The options for surpressing errors and warnings will not work with this as they do for loadXML()
e.g.
<?php
$doc->loadHTMLFile($file, LIBXML_NOWARNING | LIBXML_NOERROR);
?>
will not work.
you must use:
<?php
libxml_use_internal_errors(true);
$doc->loadHTMLFile($file);
?>
and handle the exceptions as neccesarry.

This puts the HTML into a DOM object which can be parsed by individual tags, attributes, etc.. Here is an example of getting all the 'href' attributes and corresponding node values out of the 'a' tag. Very cool....
<?php
$myhtml = <<<EOF
<html>
<head>
<title>My Page</title>
</head>
<body>
<p><a href="/mypage1">Hello World!</a></p>
<p><a href="/mypage2">Another Hello World!</a></p>
</body>
</html>
EOF;
$doc = new DOMDocument();
$doc->loadHTML($myhtml);
$tags = $doc->getElementsByTagName('a');
foreach ($tags as $tag) {
    echo $tag->getAttribute('href').' | '.$tag->nodeValue."\n";
}
?>
This should output:
/mypage1 | Hello World!
/mypage2 | Another Hello World!

<?php
// try this html listing example for all nodes / includes a few getElementsByTagName options:
$file = $DOCUMENT_ROOT. "test";
$doc = new DOMDocument();
$doc->loadHTMLFile($file);
// example 1:
$elements = $doc->getElementsByTagName('*');
// example 2:
$elements = $doc->getElementsByTagName('html');
// example 3:
//$elements = $doc->getElementsByTagName('body');
// example 4:
//$elements = $doc->getElementsByTagName('table');
// example 5:
//$elements = $doc->getElementsByTagName('div');
if (!is_null($elements)) {
 foreach ($elements as $element) {
  echo "<br/>". $element->nodeName. ": ";
  $nodes = $element->childNodes;
  foreach ($nodes as $node) {
   echo $node->nodeValue. "\n";
  }
 }
}
?>

In this post http://softontherocks.blogspot.com/2014/11/descargar-el-contenido-de-una-url_11.html I found a simple way to get the content of a URL with DOMDocument, loadHTMLFile and saveHTML().
function getURLContent($url){
  $doc = new DOMDocument;
  $doc->preserveWhiteSpace = FALSE;
  @$doc->loadHTMLFile($url);
  return $doc->saveHTML();
}

If you want to suppress output warnings from loadHTMLFile($url), put an @ sign in front. This even works in:
<?php
$load = @$dom->loadHTMLFile($url);
?>

Note that this function doesn't parse the individual tags WITHIN the html file - it's all loaded as a "black box", and you end up with an XML widget that comprises nothing but the complete chunk of HTML. 
I was hoping it would function as a sort of HTML-validator/parser, but that doesn't seem to be the case.