XML::LibXML::Error(3pmUser Contributed Perl DocumentatiXML::LibXML::Error(3pm)NAMEXML::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:
· XML_ERR_NONE = 0
· XML_ERR_WARNING = 1 : A simple warning.
· XML_ERR_ERROR = 2 : A recoverable error.
· 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 v5.10.0 2009-10-07 XML::LibXML::Error(3pm)
