1 package SL::Controller::Base;
3 use parent qw(Rose::Object);
5 use List::Util qw(first);
8 # public/helper functions
11 sub parse_html_template {
14 my $locals = shift || {};
16 return $::form->parse_html_template($name, { %{ $locals }, SELF => $self });
22 return $_[0] if (scalar(@_) == 1) && !ref($_[0]);
24 my %params = ref($_[0]) eq 'HASH' ? %{ $_[0] } : @_;
25 my $controller = delete($params{controller}) || $self->_controller_name;
26 my $action = delete($params{action}) || 'dispatch';
27 $params{action} = "${controller}/${action}";
28 my $query = join('&', map { $::form->escape($_) . '=' . $::form->escape($params{$_}) } keys %params);
30 return "controller.pl?${query}";
35 my $url = $self->url_for(@_);
37 print $::cgi->redirect($url);
41 # private functions -- for use in Base only
46 my $action = "action_" . shift;
48 return $self->_dispatch(@_) if $action eq 'action_dispatch';
50 $::form->error("Invalid action ${action} for controller " . ref($self)) if !$self->can($action);
54 sub _controller_name {
55 return (split(/::/, ref($_[0])))[-1];
61 my @actions = grep { m/^action_/ } keys %{ ref($self) . "::" };
62 my $action = first { $::form->{$_} } @actions;
73 SL::Controller::Base - base class for all action controllers
79 This is a base class for all action controllers. Action controllers
80 provide subs that are callable by special URLs.
82 For each request made to the web server an instance of the controller
83 will be created. After the request has been served that instance will
84 handed over to garbage collection.
86 This base class is derived from L<Rose::Object>.
90 The URLs have the following properties:
96 The script part of the URL must be C<controller.pl>.
100 There must be a GET or POST parameter named C<action> containing the
101 name of the controller and the sub to call separated by C</>,
102 e.g. C<Message/list>.
106 The controller name is the package's name without the
107 C<SL::Controller::> prefix. At the moment only packages in the
108 C<SL::Controller> namespace are valid; sub-namespaces are not
109 allowed. The package name must start with an upper-case letter.
113 The sub part of the C<action> parameter is the name of the sub to
114 call. However, the sub's name is automatically prefixed with
115 C<action_>. Therefore for the example C<Message/list> the sub
116 C<SL::DB::Message::action_list> would be called. This in turn means
117 that subs whose name does not start with C<action_> cannot be invoked
118 directly via the URL.
122 =head2 INDIRECT DISPATCHING
124 In the case that there are several submit buttons on a page it is
125 often impractical to have a single C<action> parameter match up
126 properly. For such a case a special dispatcher method is available. In
127 that case the C<action> parameter of the URL must be
128 C<Controller/dispatch>.
130 The C<SL::Controller::Base::_dispatch> method will iterate over all
131 subs in the controller package whose names start with C<action_>. The
132 first one for which there's a GET or POST parameter with the same name
133 and that's trueish is called.
135 Usage from a template usually looks like this:
137 <form method="POST" action="controller.pl">
139 <input type="hidden" name="action" value="Message/dispatch">
140 <input type="submit" name="action_mark_as_read" value="Mark messages as read">
141 <input type="submit" name="action_delete" value="Delete messages">
144 The dispatching is handled by the function L</_dispatch>.
148 =head2 PUBLIC HELPER FUNCTIONS
150 These functions are supposed to be called by sub-classed controllers.
154 =item C<parse_html_template $file_name, $local_variables>
156 Outputs an HTML template. It is a thin wrapper around
157 C<Form::parse_html_template> which also adds the current object as the
158 template variable C<SELF>.
160 =item C<url_for $url>
162 =item C<url_for $params>
164 =item C<url_for %params>
166 Creates an URL for the given parameters suitable for calling an action
167 controller. If there's only one scalar parameter then it is returned
170 Otherwise the parameters are given either as a single hash ref
171 parameter or as a normal hash.
173 The controller to call is given by C<$params{controller}>. It defaults
174 to the current controller as returned by
175 L</_controller_name>.
177 The action to call is given by C<$params{action}>. It defaults to
180 All other key/value pairs in C<%params> are appended as GET parameters
183 Usage from a template might look like this:
185 <a href="[% SELF.url_for(controller => 'Message', action => 'new', recipient_id => 42) %]">create new message</a>
187 =item redirect_to %url_params
189 Redirects the browser to a new URL by outputting a HTTP redirect
190 header. The URL is generated by calling L</url_for> with
195 =head2 PRIVATE FUNCTIONS
197 These functions are supposed to be used from this base class only.
201 =item C<_controller_name>
203 Returns the name of the curernt controller package without the
204 C<SL::Controller::> prefix.
208 Implements the method lookup for indirect dispatching mentioned in the
209 section L</INDIRECT DISPATCHING>.
211 =item C<_run_action $action>
213 Executes a sub based on the value of C<$action>. C<$action> is the sub
214 name part of the C<action> GET or POST parameter as described in
217 If C<$action> equals C<dispatch> then the sub L</_dispatch> in this
218 base class is called for L</INDIRECT DISPATCHING>. Otherwise
219 C<$action> is prefixed with C<action_>, and that sub is called on the
220 current controller instance.
226 Moritz Bunkus E<lt>m.bunkus@linet-services.deE<gt>