Edit report at https://bugs.php.net/bug.php?id=55459&edit=1
ID: 55459
Updated by: bj...@php.net
Reported by: scope at planetavent dot de
Summary: Unable to differentiate between end of file or read
error
-Status: Open
+Status: Wont fix
Type: Bug
Package: XML Reader
Operating System: Ubuntu 10.04 LTS
PHP Version: 5.3.7
Block user comment: N
Private report: N
New Comment:
If an error occurred libxml_get_errors() will be populated with details on the
error.
Previous Comments:
------------------------------------------------------------------------
[2011-08-19 09:56:22] scope at planetavent dot de
Description:
------------
We were forced into using xmlreader the other day due to xml file sizes.
Usually we use DOM to check for well-formedness and schema validity.
It seems, that it is currently not possible to differentiate between a reading
error (e.g. not well formed) and "end of file" using xmlreader.
Unfortunately it is not possible to call XMLReader::isValid() after an
unsuccessful read when using a schema. Of course, if the document is not
well-formed it can't be valid. But isValid() just calls onto
xmlTextReaderIsValid() which seems to work only, if the node pointer was able
to advance correctly (which is not the case for that kind of error). So this is
not an option.
>From ext/xmlreader/php_xmlreader.c:806
retval = xmlTextReaderRead(intern->ptr);
if (retval == -1) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "An Error Occured while
reading");
RETURN_FALSE;
} else {
RETURN_BOOL(retval);
}
and
>From ext/xmlreader/php_xmlreader.c:849
if (retval == -1) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "An Error Occured while
reading");
RETURN_FALSE;
} else {
RETURN_BOOL(retval);
}
According to libxml, the result of xmlTextReaderRead() is
"1 if the node was read successfully, 0 if there is no more nodes to read, or
-1 in case of error".
Therefor PHP should return true, int(0) or false to be able to check for
reading errors.
I'm not quite sure if this can be considered a bug. To my mind it is, because
it prevents me from using xmlreader in a proper way and as a result, renders it
very difficult to work on huge xml files.
libxml is able to distinguish between both conditions, so should php.
Test script:
---------------
<?php
libxml_use_internal_errors( true );
$file = "input.xml";
$xr = new XMLReader();
$xr->open( $file );
while ( true )
{
$success = $xr->read();
if ( !$success )
{
# end of file or error?
var_dump( $success );
echo "no success\n";
break;
}
else
{
echo "read success\n";
}
}
Expected result:
----------------
Ability to check for int(0) = no elements to read and false = error during read.
Actual result:
--------------
[...]
read success
read success
read success
Warning: XMLReader::read(): An Error Occured while reading in X:\xmlreader.php
on line 12
bool(false)
no success
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=55459&edit=1
