1XML::LibXML::Error(3) User Contributed Perl DocumentationXML::LibXML::Error(3)
2
6 XML::LibXML::Error - Structured Errors
7
9 eval { ... };
10 if (ref($@)) {
11 # handle a structured error (XML::LibXML::Error object)
12 } elsif ($@) {
13 # error, but not an XML::LibXML::Error object
14 } else {
15 # no error
16 }
17 $XML::LibXML::Error::WARNINGS=1;
19 $message = $@->as_string();
20 print $@->dump();
21 $error_domain = $@->domain();
22 $error_code = $@->code();
23 $error_message = $@->message();
24 $error_level = $@->level();
25 $filename = $@->file();
26 $line = $@->line();
27 $nodename = $@->nodename();
28 $error_str1 = $@->str1();
29 $error_str2 = $@->str2();
30 $error_str3 = $@->str3();
31 $error_num1 = $@->num1();
32 $error_num2 = $@->num2();
33 $string = $@->context();
34 $offset = $@->column();
35 $previous_error = $@->_prev();
36
38 The XML::LibXML::Error class is a tiny frontend to libxml2's structured
39 error support. If XML::LibXML is compied with structured error support,
40 all errors reported by libxml2 are transformed to XML::LibXML:Error
41 objects. These objects automatically serialize to the corresponding
42 error messages when printed or used in a string operation, but as
43 objects, can also be used to get a detailed and structured information
44 about the error that occurred.
45 Unlike most other XML::LibXML objects, XML::LibXML::Error doesn't wrap
47 an underlying libxml2 structure directly, but rather transforms it to a
48 blessed Perl hash reference containing the individual fields of the
49 structured error information as hash key-value pairs. Individual items
50 (fields) of a structured error can either be obtained directly as
51 $@->{field}, or using autoloaded methods such as as $@->field() (where
52 field is the field name). XML::LibXML::Error objects have the following
53 fields: domain, code, level, file, line, nodename, message, str1, str2,
54 str3, num1, num2, and _prev (some of them may be undefined).
55 $XML::LibXML::Error::WARNINGS
57 $XML::LibXML::Error::WARNINGS=1;
58 Traditionally, XML::LibXML was supressing parser warnings by
60 setting libxml2's global variable xmlGetWarningsDefaultValue to 0.
61 Since 1.70 we do not change libxml2's global variables anymore; for
62 backward compatibility, XML::LibXML suppresses warnings. This
63 variable can be set to 1 to enable reporting of these warnings via
64 Perl "warn" and to 2 to report hem via "die".
65 $message = $@->as_string();
67 This functions takes serializes a XML::LibXML::Error object to a
69 string containing the full error message close to the message
70 produced by libxml2 default error handlers and tools like xmllint.
71 This method is also used to overload "" operator on
72 XML::LibXML::Error, so it is automatically called whenever
73 XML::LibXML::Error object is treated as a string (e.g. in print
74 $@).
75 dump
77 print $@->dump();
78 This function serializes a XML::LibXML::Error to a string
80 displaying all fields of the error structure individually on
81 separate lines of the form 'name' => 'value'.
82 domain
84 $error_domain = $@->domain();
85 Returns string containing information about what part of the
87 library raised the error. Can be one of: "parser", "tree",
88 "namespace", "validity", "HTML parser", "memory", "output", "I/O",
89 "ftp", "http", "XInclude", "XPath", "xpointer", "regexp", "Schemas
90 datatype", "Schemas parser", "Schemas validity", "Relax-NG parser",
91 "Relax-NG validity", "Catalog", "C14N", "XSLT", "validity".
92 code
94 $error_code = $@->code();
95 Returns the actual libxml2 error code. The XML::LibXML::ErrNo
97 module defines constants for individual error codes. Currently
98 libxml2 uses over 480 different error codes.
99 message
101 $error_message = $@->message();
102 Returns a human-readable informative error message.
104 level
106 $error_level = $@->level();
107 Returns an integer value describing how consequent is the error.
109 XML::LibXML::Error defines the following constants:
110 · XML_ERR_NONE = 0
112 · XML_ERR_WARNING = 1 : A simple warning.
114 · XML_ERR_ERROR = 2 : A recoverable error.
116 · XML_ERR_FATAL = 3 : A fatal error.
118 file
120 $filename = $@->file();
121 Returns the filename of the file being processed while the error
123 occurred.
124 line
126 $line = $@->line();
127 The line number, if available.
129 nodename
131 $nodename = $@->nodename();
132 Name of the node where error occurred, if available. When this
134 field is non-empty, libxml2 actually returned a physical pointer to
135 the specified node. Due to memory management issues, it is very
136 difficult to implement a way to expose the pointer to the Perl
137 level as a XML::LibXML::Node. For this reason, XML::LibXML::Error
138 currently only exposes the name the node.
139 str1
141 $error_str1 = $@->str1();
142 Error specific. Extra string information.
144 str2
146 $error_str2 = $@->str2();
147 Error specific. Extra string information.
149 str3
151 $error_str3 = $@->str3();
152 Error specific. Extra string information.
154 num1
156 $error_num1 = $@->num1();
157 Error specific. Extra numeric information.
159 num2
161 $error_num2 = $@->num2();
162 In recent libxml2 versions, this value contains a column number of
164 the error or 0 if N/A.
165 context
167 $string = $@->context();
168 For parsing errors, this field contains about 80 characters of the
170 XML near the place where the error occurred. The field
171 "$@->column()" contains the corresponding offset. Where N/A, the
172 field is undefined.
173 column
175 $offset = $@->column();
176 See "$@->column()" above.
178 _prev
180 $previous_error = $@->_prev();
181 This field can possibly hold a reference to another
183 XML::LibXML::Error object representing an error which occurred just
184 before this error.
185
187 Matt Sergeant, Christian Glahn, Petr Pajas
188
190 1.70
191
193 2001-2007, AxKit.com Ltd.
194 2002-2006, Christian Glahn.
196 2006-2009, Petr Pajas.
198perl v5.12.0 2009-10-07 XML::LibXML::Error(3)