1Glib::Error(3) User Contributed Perl Documentation Glib::Error(3)
2
6 Glib::Error - Exception Objects based on GError
7
9 eval {
10 my $pixbuf = Gtk2::Gdk::Pixbuf->new_from_file ($filename);
11 $image->set_from_pixbuf ($pixbuf);
12 };
13 if ($@) {
14 print "$@\n";
15 if (Glib::Error::matches ($@, 'Gtk2::Gdk::Pixbuf::Error',
16 'unknown-format')) {
17 change_format_and_try_again ();
18 } elsif (Glib::Error::matches ($@, 'Glib::File::Error', 'noent')) {
19 change_source_dir_and_try_again ();
20 } else {
21 # don't know how to handle this
22 die $@;
23 }
24 }
25
27 Gtk2-Perl translates GLib's GError runtime errors into Perl exceptions,
28 by creating exception objects based on Glib::Error. Glib::Error
29 overloads the stringification operator, so a Glib::Error object will
30 act like a string if used with print() or warn(), so most code using $@
31 will not even know the difference.
32 The point of having exception objects, however, is that the error
34 messages in GErrors are often localized with NLS translation. Thus,
35 it's not good for your code to attempt to handle errors by string
36 matching on the the error message. Glib::Error provides a way to get
37 to the deterministic error code.
38 You will typically deal with objects that inherit from Glib::Error,
40 such as Glib::Convert::Error, Glib::File::Error,
41 Gtk2::Gdk::Pixbuf::Error, etc; these classes are provided by the
42 libraries that define the error domains. However, it is possible to
43 get a base Glib::Error when the bindings encounter an unknown or
44 unbound error domain. The interface used here degrades nicely in such
45 a situation, but in general you should submit a bug report to the
46 binding maintainer if you get such an exception.
47
49 scalar = Glib::Error::new ($class, $code, $message)
50 scalar = $class->new ($code, $message)
51 · $code (Glib::Enum) an enumeration value, depends on $class
52 · $message (string)
54 Create a new exception object of type $class, where $class is
56 associated with a GError domain. $code should be a value from the
57 enumeration type associated with this error domain. $message can be
58 anything you like, but should explain what happened from the point of
59 view of a user.
60 integer = $error->code
62 This is the numeric error code. Normally, you'll want to use "value"
63 instead, for readability.
64 string = $error->domain
66 The error domain. You normally do not need this, as the object will be
67 blessed into a corresponding class.
68 string = $error->location
70 The source line and file closest to the emission of the exception, in
71 the same format that you'd get from croak() or die().
72 If there's non-ascii characters in the filename Perl leaves them as raw
74 bytes, so you may have to put the string through
75 Glib::filename_display_name for a wide-char form.
76 boolean = $error->matches ($domain, $code)
78 · $domain (string)
79 · $code (scalar)
81 Returns true if the exception in $error matches the given $domain and
83 $code. $domain may be a class name or domain quark (that is, the real
84 string used in C). $code may be an integer value or an enum nickname;
85 the enum type depends on the value of $domain.
86 string = $error->message
88 The error message. This may be localized, as it is intended to be
89 shown to a user.
90 Glib::Error::register ($package, $enum_package)
92 · $package (string) class name to register as a Glib::Error.
93 · $enum_package (string) class name of the enum type to use for this
95 domain's error codes.
96 Register a new error domain. Glib::Error will be added @package::ISA
98 for you. enum_package must be a valid Glib::Enum type, either from a C
99 library or registered with "Glib::Type::register_enum". After
100 registering an error domain, you can create or throw exceptions of this
101 type.
102 scalar = Glib::Error::throw ($class, $code, $message)
104 scalar = $class->throw ($code, $message)
105 · $code (Glib::Enum) an enumeration value, depends on $class
106 · $message (string)
108 Throw an exception with a Glib::Error exception object. Equivalent to
110 "croak (Glib::Error::new ($class, $code, $message));".
111 string = $error->value
113 The enumeration value nickname of the integer value in "$error->code",
114 according to this error domain. This will not be available if the
115 error object is a base Glib::Error, because the bindings will have no
116 idea how to get to the correct nickname.
117
119 Glib
120
122 Copyright (C) 2003-2009 by the gtk2-perl team.
123 This software is licensed under the LGPL. See Glib for a full notice.
125perl v5.12.1 2010-07-07 Glib::Error(3)