1Catalyst::View::TT(3) User Contributed Perl DocumentationCatalyst::View::TT(3)
2
6 Catalyst::View::TT - Template View Class
7
9 # use the helper to create your View
10 myapp_create.pl view TT TT
12 # configure in lib/MyApp.pm (Could be set from configfile instead)
14 __PACKAGE__->config(
16 name => 'MyApp',
17 root => MyApp->path_to('root'),
18 default_view => 'TT',
19 'View::TT' => {
20 # any TT configurations items go here
21 INCLUDE_PATH => [
22 MyApp->path_to( 'root', 'src' ),
23 MyApp->path_to( 'root', 'lib' ),
24 ],
25 TEMPLATE_EXTENSION => '.tt',
26 CATALYST_VAR => 'c',
27 TIMER => 0,
28 # Not set by default
29 PRE_PROCESS => 'config/main',
30 WRAPPER => 'site/wrapper',
31 render_die => 1, # Default for new apps, see render method docs
32 },
33 );
34 # render view from lib/MyApp.pm or
36 lib/MyApp::Controller::SomeController.pm
37 sub message : Global {
39 my ( $self, $c ) = @_;
40 $c->stash->{template} = 'message.tt2';
41 $c->stash->{message} = 'Hello World!';
42 $c->forward( $c->view('TT') );
43 }
44 # access variables from template
46 The message is: [% message %].
48 # example when CATALYST_VAR is set to 'Catalyst'
50 Context is [% Catalyst %]
51 The base is [% Catalyst.req.base %]
52 The name is [% Catalyst.config.name %]
53 # example when CATALYST_VAR isn't set
55 Context is [% c %]
56 The base is [% base %]
57 The name is [% name %]
58
60 This is the Catalyst view class for the Template Toolkit. Your
61 application should defined a view class which is a subclass of this
62 module. The easiest way to achieve this is using the myapp_create.pl
63 script (where myapp should be replaced with whatever your application
64 is called). This script is created as part of the Catalyst setup.
65 $ script/myapp_create.pl view TT TT
67 This creates a MyApp::View::TT.pm module in the lib directory (again,
69 replacing "MyApp" with the name of your application) which looks
70 something like this:
71 package FooBar::View::TT;
73 use strict;
75 use warnings;
76 use base 'Catalyst::View::TT';
78 __PACKAGE__->config(DEBUG => 'all');
80 Now you can modify your action handlers in the main application and/or
82 controllers to forward to your view class. You might choose to do this
83 in the end() method, for example, to automatically forward all actions
84 to the TT view class.
85 # In MyApp or MyApp::Controller::SomeController
87 sub end : Private {
89 my( $self, $c ) = @_;
90 $c->forward( $c->view('TT') );
91 }
92 But if you are using the standard auto-generated end action, you don't
94 even need to do this!
95 # in MyApp::Controller::Root
97 sub end : ActionClass('RenderView') {} # no need to change this line
98 # in MyApp.pm
100 __PACKAGE__->config(
101 ...
102 default_view => 'TT',
103 );
104 This will Just Work. And it has the advantages that:
106 · If you want to use a different view for a given request, just set
108 << $c->stash->{current_view} >>. (See Catalyst's "$c->view" method
109 for details.
110 · << $c->res->redirect >> is handled by default. If you just forward
112 to "View::TT" in your "end" routine, you could break this by
113 sending additional content.
114 See Catalyst::Action::RenderView for more details.
116 CONFIGURATION
118 There are a three different ways to configure your view class. The
119 first way is to call the "config()" method in the view subclass. This
120 happens when the module is first loaded.
121 package MyApp::View::TT;
123 use strict;
125 use base 'Catalyst::View::TT';
126 MyApp::View::TT->config({
128 INCLUDE_PATH => [
129 MyApp->path_to( 'root', 'templates', 'lib' ),
130 MyApp->path_to( 'root', 'templates', 'src' ),
131 ],
132 PRE_PROCESS => 'config/main',
133 WRAPPER => 'site/wrapper',
134 });
135 The second way is to define a "new()" method in your view subclass.
137 This performs the configuration when the view object is created,
138 shortly after being loaded. Remember to delegate to the base class
139 "new()" method (via "$self->next::method()" in the example below) after
140 performing any configuration.
141 sub new {
143 my $self = shift;
144 $self->config({
145 INCLUDE_PATH => [
146 MyApp->path_to( 'root', 'templates', 'lib' ),
147 MyApp->path_to( 'root', 'templates', 'src' ),
148 ],
149 PRE_PROCESS => 'config/main',
150 WRAPPER => 'site/wrapper',
151 });
152 return $self->next::method(@_);
153 }
154 The final, and perhaps most direct way, is to define a class item in
156 your main application configuration, again by calling the ubiquitous
157 "config()" method. The items in the class hash are added to those
158 already defined by the above two methods. This happens in the base
159 class new() method (which is one reason why you must remember to call
160 it via "MRO::Compat" if you redefine the "new()" method in a subclass).
161 package MyApp;
163 use strict;
165 use Catalyst;
166 MyApp->config({
168 name => 'MyApp',
169 root => MyApp->path_to('root'),
170 'View::TT' => {
171 INCLUDE_PATH => [
172 MyApp->path_to( 'root', 'templates', 'lib' ),
173 MyApp->path_to( 'root', 'templates', 'src' ),
174 ],
175 PRE_PROCESS => 'config/main',
176 WRAPPER => 'site/wrapper',
177 },
178 });
179 Note that any configuration items defined by one of the earlier methods
181 will be overwritten by items of the same name provided by the latter
182 methods.
183 DYNAMIC INCLUDE_PATH
185 Sometimes it is desirable to modify INCLUDE_PATH for your templates at
186 run time.
187 Additional paths can be added to the start of INCLUDE_PATH via the
189 stash as follows:
190 $c->stash->{additional_template_paths} =
192 [$c->config->{root} . '/test_include_path'];
193 If you need to add paths to the end of INCLUDE_PATH, there is also an
195 include_path() accessor available:
196 push( @{ $c->view('TT')->include_path }, qw/path/ );
198 Note that if you use include_path() to add extra paths to INCLUDE_PATH,
200 you MUST check for duplicate paths. Without such checking, the above
201 code will add "path" to INCLUDE_PATH at every request, causing a memory
202 leak.
203 A safer approach is to use include_path() to overwrite the array of
205 paths rather than adding to it. This eliminates both the need to
206 perform duplicate checking and the chance of a memory leak:
207 @{ $c->view('TT')->include_path } = qw/path another_path/;
209 If you are calling "render" directly then you can specify dynamic paths
211 by having a "additional_template_paths" key with a value of additonal
212 directories to search. See "CAPTURING TEMPLATE OUTPUT" for an example
213 showing this.
214 RENDERING VIEWS
216 The view plugin renders the template specified in the "template" item
217 in the stash.
218 sub message : Global {
220 my ( $self, $c ) = @_;
221 $c->stash->{template} = 'message.tt2';
222 $c->forward( $c->view('TT') );
223 }
224 If a stash item isn't defined, then it instead uses the stringification
226 of the action dispatched to (as defined by $c->action) in the above
227 example, this would be "message", but because the default is to append
228 '.tt', it would load "root/message.tt".
229 The items defined in the stash are passed to the Template Toolkit for
231 use as template variables.
232 sub default : Private {
234 my ( $self, $c ) = @_;
235 $c->stash->{template} = 'message.tt2';
236 $c->stash->{message} = 'Hello World!';
237 $c->forward( $c->view('TT') );
238 }
239 A number of other template variables are also added:
241 c A reference to the context object, $c
243 base The URL base, from $c->req->base()
244 name The application name, from $c->config->{ name }
245 These can be accessed from the template in the usual way:
247 <message.tt2>:
249 The message is: [% message %]
251 The base is [% base %]
252 The name is [% name %]
253 The output generated by the template is stored in "$c->response->body".
255 CAPTURING TEMPLATE OUTPUT
257 If you wish to use the output of a template for some other purpose than
258 displaying in the response, e.g. for sending an email, this is possible
259 using Catalyst::Plugin::Email and the render method:
260 sub send_email : Local {
262 my ($self, $c) = @_;
263 $c->email(
265 header => [
266 To => 'me@localhost',
267 Subject => 'A TT Email',
268 ],
269 body => $c->view('TT')->render($c, 'email.tt', {
270 additional_template_paths => [ $c->config->{root} . '/email_templates'],
271 email_tmpl_param1 => 'foo'
272 }
273 ),
274 );
275 # Redirect or display a message
276 }
277 TEMPLATE PROFILING
279 See "TIMER" property of the config method.
280 METHODS
282 new
283 The constructor for the TT view. Sets up the template provider, and
284 reads the application config.
285 process($c)
287 Renders the template specified in "$c->stash->{template}" or
288 "$c->action" (the private name of the matched action). Calls render to
289 perform actual rendering. Output is stored in "$c->response->body".
290 It is possible to forward to the process method of a TT view from
292 inside Catalyst like this:
293 $c->forward('View::TT');
295 N.B. This is usually done automatically by
297 Catalyst::Action::RenderView.
298 render($c, $template, \%args)
300 Renders the given template and returns output. Throws a
301 Template::Exception object upon error.
302 The template variables are set to %$args if $args is a hashref, or
304 $"$c->stash" otherwise. In either case the variables are augmented with
305 "base" set to " << $c-"req->base >>, "c" to $c and "name" to
306 "$c->config->{name}". Alternately, the "CATALYST_VAR" configuration
307 item can be defined to specify the name of a template variable through
308 which the context reference ($c) can be accessed. In this case, the
309 "c", "base" and "name" variables are omitted.
310 $template can be anything that Template::process understands how to
312 process, including the name of a template file or a reference to a test
313 string. See Template::process for a full list of supported formats.
314 To use the render method outside of your Catalyst app, just pass a
316 undef context. This can be useful for tests, for instance.
317 It is possible to forward to the render method of a TT view from inside
319 Catalyst to render page fragments like this:
320 my $fragment = $c->forward("View::TT", "render", $template_name, $c->stash->{fragment_data});
322 Backwards compatibility note
324 The render method used to just return the Template::Exception object,
326 rather than just throwing it. This is now deprecated and instead the
327 render method will throw an exception for new applications.
328 This behaviour can be activated (and is activated in the default
330 skeleton configuration) by using "render_die => 1". If you rely on the
331 legacy behaviour then a warning will be issued.
332 To silence this warning, set "render_die => 0", but it is recommended
334 you adjust your code so that it works with "render_die => 1".
335 In a future release, "render_die => 1" will become the default if
337 unspecified.
338 template_vars
340 Returns a list of keys/values to be used as the catalyst variables in
341 the template.
342 config
344 This method allows your view subclass to pass additional settings to
345 the TT configuration hash, or to set the options as below:
346 paths
348 The list of paths TT will look for templates in.
349 "CATALYST_VAR"
351 Allows you to change the name of the Catalyst context object. If set,
352 it will also remove the base and name aliases, so you will have access
353 them through <context>.
354 For example:
356 MyApp->config({
358 name => 'MyApp',
359 root => MyApp->path_to('root'),
360 'View::TT' => {
361 CATALYST_VAR => 'Catalyst',
362 },
363 });
364 message.tt2:
366 The base is [% Catalyst.req.base %]
368 The name is [% Catalyst.config.name %]
369 "TIMER"
371 If you have configured Catalyst for debug output, and turned on the
372 TIMER setting, "Catalyst::View::TT" will enable profiling of template
373 processing (using Template::Timer). This will embed HTML comments in
374 the output from your templates, such as:
375 <!-- TIMER START: process mainmenu/mainmenu.ttml -->
377 <!-- TIMER START: include mainmenu/cssindex.tt -->
378 <!-- TIMER START: process mainmenu/cssindex.tt -->
379 <!-- TIMER END: process mainmenu/cssindex.tt (0.017279 seconds) -->
380 <!-- TIMER END: include mainmenu/cssindex.tt (0.017401 seconds) -->
381 ....
383 <!-- TIMER END: process mainmenu/footer.tt (0.003016 seconds) -->
385 "TEMPLATE_EXTENSION"
387 a sufix to add when looking for templates bases on the "match" method
388 in Catalyst::Request.
389 For example:
391 package MyApp::Controller::Test;
393 sub test : Local { .. }
394 Would by default look for a template in <root>/test/test. If you set
396 TEMPLATE_EXTENSION to '.tt', it will look for <root>/test/test.tt.
397 "PROVIDERS"
399 Allows you to specify the template providers that TT will use.
400 MyApp->config({
402 name => 'MyApp',
403 root => MyApp->path_to('root'),
404 'View::TT' => {
405 PROVIDERS => [
406 {
407 name => 'DBI',
408 args => {
409 DBI_DSN => 'dbi:DB2:books',
410 DBI_USER=> 'foo'
411 }
412 }, {
413 name => '_file_',
414 args => {}
415 }
416 ]
417 },
418 });
419 The 'name' key should correspond to the class name of the provider you
421 want to use. The _file_ name is a special case that represents the
422 default TT file-based provider. By default the name is will be
423 prefixed with 'Template::Provider::'. You can fully qualify the name
424 by using a unary plus:
425 name => '+MyApp::Provider::Foo'
427 You can also specify the 'copy_config' key as an arrayref, to copy
429 those keys from the general config, into the config for the provider:
430 DEFAULT_ENCODING => 'utf-8',
432 PROVIDERS => [
433 {
434 name => 'Encoding',
435 copy_config => [qw(DEFAULT_ENCODING INCLUDE_PATH)]
436 }
437 ]
438 This can prove useful when you want to use the
440 additional_template_paths hack in your own provider, or if you need to
441 use Template::Provider::Encoding
442 HELPERS
444 The Catalyst::Helper::View::TT and Catalyst::Helper::View::TTSite
445 helper modules are provided to create your view module. There are
446 invoked by the myapp_create.pl script:
447 $ script/myapp_create.pl view TT TT
449 $ script/myapp_create.pl view TT TTSite
451 The Catalyst::Helper::View::TT module creates a basic TT view module.
453 The Catalyst::Helper::View::TTSite module goes a little further. It
454 also creates a default set of templates to get you started. It also
455 configures the view module to locate the templates automatically.
456
458 If you are using the CGI module inside your templates, you will
459 experience that the Catalyst server appears to hang while rendering the
460 web page. This is due to the debug mode of CGI (which is waiting for
461 input in the terminal window). Turning off the debug mode using the
462 "-no_debug" option solves the problem, eg.:
463 [% USE CGI('-no_debug') %]
465
467 Catalyst, Catalyst::Helper::View::TT, Catalyst::Helper::View::TTSite,
468 Template::Manual
469
471 Sebastian Riedel, "sri@cpan.org"
472 Marcus Ramberg, "mramberg@cpan.org"
474 Jesse Sheidlower, "jester@panix.com"
476 Andy Wardley, "abw@cpan.org"
478
480 This program is free software. You can redistribute it and/or modify it
481 under the same terms as Perl itself.
482perl v5.12.1 2010-04-07 Catalyst::View::TT(3)