XML::LibXML::Error(3)					User Contributed Perl Documentation				     XML::LibXML::Error(3)

NAME

       XML::LibXML::Error - Structured Errors

SYNOPSIS

	 eval { ... };
		 if (ref($@)) {
		   # handle a structured error (XML::LibXML::Error object)
		 } elsif ($@) {
		   # error, but not an XML::LibXML::Error object
		 } else {
		   # no error
		 }

	 $XML::LibXML::Error::WARNINGS=1;
	 $message = $@->as_string();
	 print $@->dump();
	 $error_domain = $@->domain();
	 $error_code = $@->code();
	 $error_message = $@->message();
	 $error_level = $@->level();
	 $filename = $@->file();
	 $line = $@->line();
	 $nodename = $@->nodename();
	 $error_str1 = $@->str1();
	 $error_str2 = $@->str2();
	 $error_str3 = $@->str3();
	 $error_num1 = $@->num1();
	 $error_num2 = $@->num2();
	 $string = $@->context();
	 $offset = $@->column();
	 $previous_error = $@->_prev();

DESCRIPTION

       The XML::LibXML::Error class is a tiny frontend to libxml2's structured error support. If XML::LibXML is compied with structured error
       support, all errors reported by libxml2 are transformed to XML::LibXML:Error objects. These objects automatically serialize to the
       corresponding error messages when printed or used in a string operation, but as objects, can also be used to get a detailed and structured
       information about the error that occurred.

       Unlike most other XML::LibXML objects, XML::LibXML::Error doesn't wrap an underlying libxml2 structure directly, but rather transforms it
       to a blessed Perl hash reference containing the individual fields of the structured error information as hash key-value pairs. Individual
       items (fields) of a structured error can either be obtained directly as $@->{field}, or using autoloaded methods such as as $@->field()
       (where field is the field name). XML::LibXML::Error objects have the following fields: domain, code, level, file, line, nodename, message,
       str1, str2, str3, num1, num2, and _prev (some of them may be undefined).

       $XML::LibXML::Error::WARNINGS
	     $XML::LibXML::Error::WARNINGS=1;

	   Traditionally, XML::LibXML was supressing parser warnings by setting libxml2's global variable xmlGetWarningsDefaultValue to 0. Since
	   1.70 we do not change libxml2's global variables anymore; for backward compatibility, XML::LibXML suppresses warnings. This variable
	   can be set to 1 to enable reporting of these warnings via Perl "warn" and to 2 to report hem via "die".

	     $message = $@->as_string();

	   This functions takes serializes a XML::LibXML::Error object to a string containing the full error message close to the message produced
	   by libxml2 default error handlers and tools like xmllint. This method is also used to overload "" operator on XML::LibXML::Error, so it
	   is automatically called whenever XML::LibXML::Error object is treated as a string (e.g. in print $@).

       dump
	     print $@->dump();

	   This function serializes a XML::LibXML::Error to a string displaying all fields of the error structure individually on separate lines
	   of the form 'name' => 'value'.

       domain
	     $error_domain = $@->domain();

	   Returns string containing information about what part of the library raised the error. Can be one of: "parser", "tree", "namespace",
	   "validity", "HTML parser", "memory", "output", "I/O", "ftp", "http", "XInclude", "XPath", "xpointer", "regexp", "Schemas datatype",
	   "Schemas parser", "Schemas validity", "Relax-NG parser", "Relax-NG validity", "Catalog", "C14N", "XSLT", "validity".

       code
	     $error_code = $@->code();

	   Returns the actual libxml2 error code. The XML::LibXML::ErrNo module defines constants for individual error codes. Currently libxml2
	   uses over 480 different error codes.

       message
	     $error_message = $@->message();

	   Returns a human-readable informative error message.

       level
	     $error_level = $@->level();

	   Returns an integer value describing how consequent is the error.  XML::LibXML::Error defines the following constants:

	   o   XML_ERR_NONE = 0

	   o   XML_ERR_WARNING = 1 : A simple warning.

	   o   XML_ERR_ERROR = 2 : A recoverable error.

	   o   XML_ERR_FATAL = 3 : A fatal error.

       file
	     $filename = $@->file();

	   Returns the filename of the file being processed while the error occurred.

       line
	     $line = $@->line();

	   The line number, if available.

       nodename
	     $nodename = $@->nodename();

	   Name of the node where error occurred, if available. When this field is non-empty, libxml2 actually returned a physical pointer to the
	   specified node.  Due to memory management issues, it is very difficult to implement a way to expose the pointer to the Perl level as a
	   XML::LibXML::Node. For this reason, XML::LibXML::Error currently only exposes the name the node.

       str1
	     $error_str1 = $@->str1();

	   Error specific. Extra string information.

       str2
	     $error_str2 = $@->str2();

	   Error specific. Extra string information.

       str3
	     $error_str3 = $@->str3();

	   Error specific. Extra string information.

       num1
	     $error_num1 = $@->num1();

	   Error specific. Extra numeric information.

       num2
	     $error_num2 = $@->num2();

	   In recent libxml2 versions, this value contains a column number of the error or 0 if N/A.

       context
	     $string = $@->context();

	   For parsing errors, this field contains about 80 characters of the XML near the place where the error occurred. The field
	   "$@->column()" contains the corresponding offset. Where N/A, the field is undefined.

       column
	     $offset = $@->column();

	   See "$@->column()" above.

       _prev
	     $previous_error = $@->_prev();

	   This field can possibly hold a reference to another XML::LibXML::Error object representing an error which occurred just before this
	   error.

AUTHORS

       Matt Sergeant, Christian Glahn, Petr Pajas

VERSION

       1.70

COPYRIGHT

       2001-2007, AxKit.com Ltd.

       2002-2006, Christian Glahn.

       2006-2009, Petr Pajas.

perl v5.12.1							    2009-10-07						     XML::LibXML::Error(3)