Description:
------------
I need to validate XML files before loading them, then I created a DTD and hosted it.

With python I can distribute the DTD file with the program and validate the XML file locally.
A python example:
---
from lxml import etree
from StringIO import StringIO

xmlstart="""<?xml version="1.0" encoding="utf8"?>
<!DOCTYPE example PUBLIC '-//Example//Example DTD' 'http://example.com/mydtd.dtd'>"""

xmlok=xmlstart+"<example>The XML file</example>";
xmlinvalid=xmlstart+"<example><a>test</a>The XML file</example>";

dtddata="<!ELEMENT example (#PCDATA) >";

f=StringIO(dtddata);
dtd=etree.DTD(f);

print "Valid XML:";
xml1=etree.XML(xmlok);
validation=dtd.validate(xml1);
print validation;
print dtd.error_log.filter_from_errors();

print "Invalid XML:";
xml2=etree.XML(xmlinvalid);
validation=dtd.validate(xml2);
print validation;
print dtd.error_log.filter_from_errors();
----
The only way I find to port this stript is using DOMDocument::validate() but this method will get the DTD from http://example.com/mydtd.dtd and be slower, generate traffic, and fail when example.com is off-line...

I suggest adding an attribute like DOMDocument::validate($source) where $source is a string with DTD source to avoid situations like this...

Reproduce code:
---------------
<?php
$xmlstart=<<<XML
<?xml version="1.0" encoding="utf8"?>
<!DOCTYPE example PUBLIC '-//Example//Example DTD' 'http://example.com/mydtd.dtd'>
XML;

$xmlok=$xmlstart."<example>The XML file</example>";
$xmlinvalid=$xmlstart."<example><a>test</a>The XML file</example>";
$dtddata="<!ELEMENT example (#PCDATA) >";

print "<h1>Valid XML:</h1>";
$xml1=DOMDocument::loadXML($xmlok);
$validation=(int)$xml1->validate($dtddata); //Example that would work
print "<p><b>$validation</b></p>";
print "<h1>Invalid XML:</h1>";
$xml1=DOMDocument::loadXML($xmlinvalid);
$validation=(int)$xml1->validate($dtddata); //Example that would work
print "<p><b>$validation</b></p>";
?>

Expected result:
----------------
Valid XML:

1

Invalid XML:

Warning: DOMDocument::validate() [function.DOMDocument-validate]: Element example was declared #PCDATA but contains non text nodes in /script/path/xml.php on line 19

Warning: DOMDocument::validate() [function.DOMDocument-validate]: No declaration for element a in /script/path/xml.php on line 19

0

Actual result:
--------------
When no argument is passed to validate and DTD server is off-line:

Valid XML:

Warning: DOMDocument::validate(http://example.com/mydtd.dtd) [function.DOMDocument-validate]: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in /script/path/xml.php on line 14

Warning: DOMDocument::validate() [function.DOMDocument-validate]: I/O warning : failed to load external entity "http://example.com/mydtd.dtd" in /script/path/xml.php on line 14

Warning: DOMDocument::validate() [function.DOMDocument-validate]: Could not load the external subset "http://example.com/mydtd.dtd" in /script/path/xml.php on line 14

0

Invalid XML:

Warning: DOMDocument::validate(http://example.com/mydtd.dtd) [function.DOMDocument-validate]: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in /script/path/xml.php on line 19

Warning: DOMDocument::validate() [function.DOMDocument-validate]: I/O warning : failed to load external entity "http://example.com/mydtd.dtd" in /script/path/xml.php on line 19

Warning: DOMDocument::validate() [function.DOMDocument-validate]: Could not load the external subset "http://example.com/mydtd.dtd" in /script/path/xml.php on line 19

0