Q:

Removing DocDocument warning while parsing page content

I am trying to parse the content of any url.  Which should not content any html code. 
This works fine, but gives bunch of error while reading the content on url given.  How to remove this warning? 
<? php
$url= 'http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page';
$doc = new DOMDocument();
$doc->loadHTMLFile($url);
$xpath = new DOMXPath($doc);
foreach($xpath->query("//script") as $script) {
    $script->parentNode->removeChild($script);
}
$textContent = $doc->textContent; //inherited from DOMNode
echo $textContent;
? >

Warnings:
content-from-a-web-page, line: 255 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): htmlParseEntityRef: expecting ';' in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 255 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): htmlParseEntityRef: expecting ';' in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 273 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): htmlParseEntityRef: expecting ';' in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 273 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): htmlParseEntityRef: expecting ';' in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 412 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): htmlParseEntityRef: expecting ';' in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 412 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): htmlParseEntityRef: expecting ';' in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 551 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): htmlParseEntityRef: expecting ';' in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 551 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

Warning: DOMDocument::loadHTMLFile(): ID display-name already defined in http://stackoverflow.com/questions/12097352/how-can-i-parse-dynamic-content-from-a-web-page, line: 731 in /opt/lampp/htdocs/FB/ec2/test.php on line 13

A:

You can use libxml_use_internal_errors() and do the following:
libxml_use_internal_errors(true);
$doc->loadHTMLFile($url);
libxml_clear_errors();

As Peehaa noted in the comments below, it's a good idea to reset the state of errors.  You can do it as below:
$errors = libxml_use_internal_errors(true); //store
$doc->loadHTMLFile($url);
libxml_clear_errors();
libxml_use_internal_errors($errors); //reset back to previous state

Here's how it works:

libxml_use_internal_errors() tells libxml to handle the errors and warnings internally, and that it shouldn't be outputted to the browser.  Also store the current state of errors in a variable
then you load the HTML file with loadHTML() method
clear the error buffer with libxml_clear_errors
restores the old state of error values

Demo!