1AutoRunmode(3) User Contributed Perl Documentation AutoRunmode(3)
2
6 CGI::Application::Plugin::AutoRunmode - CGI::App plugin to
7 automatically register runmodes
8
10 Using subroutine attributes:
11 package MyApp;
13 use base 'CGI::Application';
14 use CGI::Application::Plugin::AutoRunmode;
15 sub my_run_mode : StartRunmode {
17 # do something here
18 }
19 sub another_run_mode : Runmode {
21 # do something else
22 }
23 # you now have two run modes
25 # "my_run_mode" and "another_run_mode"
26 # "my_run_mode" is the start (default) run mode
27 Declare that every method in a (delegate) class is a run mode.
29 package MyAppRunmodes;
31 # the delegate class
32 sub my_run_mode {
33 my ($app, $delegate) = @_;
34 # do something here
35 }
36 sub another_run_mode {
38 # do something else
39 }
40 package MyApp;
42 use base 'CGI::Application';
43 sub setup{
45 my ($self) = @_;
46 my $delegate = 'MyAppRunmodes';
47 # $delegate can be a class name or an object
48 $self->param('::Plugin::AutoRunmode::delegate' => $delegate);
49 }
50 # you now have two run modes
52 # "my_run_mode" and "another_run_mode"
53
55 This plugin for CGI::Application provides easy ways to setup run modes.
56 You can just write the method that implement a run mode, you do not
57 have to explicitly register it with CGI::App anymore.
58 There are two approaches:
60 Declare run modes with subroutine attributes.
62 You can flag methods in your CGI::App subclass with the attribute
63 "Runmode" or "StartRunmode" (these attributes are case-insensitive)
64 Declare that every method in a class is a run mode.
66 You can assign a delegate object, all whose methods will become
67 runmodes
68 You can also mix both approaches.
70 Delegate runmodes receive two parameters: The first one is the
72 CGI::App instance, followed by the delegate instance or class name.
73 This can be useful if you have delegate objects that contain state.
74 It is possible to chain multiple delegates by specifying an array
76 reference containing the delegate instances or class names. This
77 chain is checked from left to right and the runmode will be
78 delegated to the first match.
79 It both cases, the resulting runmodes will have the same name as the
81 subroutine that implements them. They are activated by a cgiapp_prerun
82 hook provided by this plugin (if you are using CGI::Application older
83 than version 4, hooks are not available, and you can import a
84 cgiapp_prerun method instead).
85 EXPORT
87 This module needs to export some symbols to do its job.
88 First of all, there are the handlers for the Runmode attribute.
90 In addition to that, the cgiapp_prerun hook is installed in your
92 application class. This is not done as an export per se, but the hook
93 installation is still done in the import subroutine. Sound confusing,
94 is confusing, but you do not really need to know what is going on
95 exactly, just keep in mind that in order to let things go on, you have
96 to "use" the module with the default exports:
97 use CGI::Application::Plugin::AutoRunmode;
99 and not
101 use CGI::Application::Plugin::AutoRunmode ();
103 # this will disable the Runmode attributes
104 # DO NOT DO THIS
105 You can also explicitly import the cgiapp_prerun method. This will
107 disable the installation of the hook. Basically, you only want to do
108 this if you are using CGI::Application prior to version 4, where hooks
109 are not supported.
110 use CGI::Application::Plugin::AutoRunmode
112 qw [ cgiapp_prerun];
113 # do this if you use CGI::Application version 3.x
114 How does it work?
116 After CGI::App has determined the name of the run mode to be executed
117 in the normal way, cgiapp_prerun checks if such a run mode exists in
118 the map configured by $self->run_modes().
119 If the run mode already exists, it gets executed normally (this module
121 does nothing). This means that you can mix the ways to declare run
122 modes offered by this plugin with the style provided by core CGI::App.
123 If that is not the case, it tries to find a method of the same name in
125 the application class (or its superclasses) that has been flagged as a
126 Runmode. If it finds one, it augments the mapping with a subroutine
127 reference to that method.
128 If that step fails, it looks if a delegate has been defined and
130 searches the methods of that delegate object for one that matches the
131 name of the runmode.
132 The runmode can then be executed by CGI::App as if it had been set up
134 by $self->run_modes() in the first place.
135 The run mode called "start"
137 Note that because the plugin only gets activated when you call a run
139 mode that is not registered in the usual run mode map, you cannot use
140 it to create a run mode called "start". The CGI:App base class always
141 registers a run mode of that name.
142 Does it still work if I change the run mode in cgiapp_prerun ?
144 If you have a cgiapp_prerun method and change the run mode there, the
145 installed hook will not be able to catch it (because of the ordering of
146 hooks).
147 So, if you do that, you have to explicitly make this call before
149 returning from cgiapp_prerun:
150 CGI::Application::Plugin::AutoRunmode::cgiapp_prerun($self);
152 Again, this is only necessary if you change the run mode (to one that
154 needs the auto-detection feature).
155 Also, this kind of code can be used with CGI::App 3.x if you have a
157 cgiapp_prerun.
158 StartRunmode
160 The attribute StartRunmode designates that subroutine to be the start
161 (default) run mode. If you use this feature, the "traditional" way of
162 setting the start run mode (calling "$self->start_mode('name')") is
163 disabled and can no longer be used in this application (including
164 subclasses and instance scripts).
165 ErrorRunmode
167 The attribute ErrorRunmode designates that subroutine to be the error
168 run mode. If you use this feature, the "traditional" way of setting the
169 error run mode (calling "$self->error_mode('name')") is disabled and
170 can no longer be used in this application (including subclasses and
171 instance scripts). This feature requires CGI::App of at least version
172 3.30.
173 Note that this "error run mode" is not a run mode that is directly
175 accessible using its name as a query parameter. It will only be
176 dispatched to internally if the original run mode produced an error.
177 This is exactly how plain CGI:App "error_mode" behaves as well (you
178 could still declare the method to also be a ":Runmode" ).
179 A word on security
181 The whole idea of this module (to reduce code complexity by
182 automatically mapping a URL to a subroutine that gets executed) is a
183 potential security hazard and great care has to be taken so that a
184 remote user cannot run code that you did not intend them to.
185 In order to prevent a carefully crafted URL to access code in other
187 packages, this module disallows non-word characters (such as : ) in
188 run mode names.
189 Also, you have to make sure that when using a delegate object, that it
191 (and its superclasses) only contain run modes (and no other
192 subroutines).
193 The following run mode names are disallowed by this module:
195 can isa VERSION AUTOLOAD new DESTROY
197 Effect on the run_modes map
199 This module only inserts the current run mode into the run_mode map
200 (unless it is already in there). It does not place any other :Runmodes
201 there. As a result of this behaviour, users of AutoRunmode will most
202 likely find the run mode map almost completely empty. This can lead to
203 strange results if you expect a more complete list of possible run
204 modes there. At this time, there is no workaround for this. Feel free
205 to complain to the author if you have a requirement here.
206 It is possible, however, to query the AutoRunmode plugin if an
208 AutoRunmode exists for a given name.
209 my $check = CGI::Application::Plugin::AutoRunmode::is_auto_runmode($self, $name)
211 This function returns a code ref if such an AutoRunmode exists.
213
215 • CGI::Application::Plugin::AutoRunmode::FileDelegate
216 • CGI::Application
218 • The CGI::App wiki at <http://www.cgi-app.org/>.
220 • CGI::Application::Plugin::ActionDispatch provides an alternative
222 set of attributes that dispatch according to PATH_INFO. It is very
223 similar to the mechanism used in the Catalyst framework.
224
226 Thilo Planz, <thilo@cpan.org>
227
229 Please use the request tracker at CPAN to report bugs or feature
230 requests:
231 <https://rt.cpan.org/Public/Dist/Display.html?Name=CGI-Application-Plugin-AutoRunmode>
232 If you want to support the development of this module with money, you
234 can donate using Flattr: <https://flattr.com/thing/132835>
235
237 Copyright 2004-2011 by Thilo Planz
238 This library is free software; you can redistribute it and/or modify it
240 under the same terms as Perl itself.
241perl v5.32.1 2021-01-26 AutoRunmode(3)