1Catalyst::Response(3) User Contributed Perl DocumentationCatalyst::Response(3)
2
6 Catalyst::Response - stores output responding to the current client
7 request
8
10 $res = $c->response;
11 $res->body;
12 $res->code;
13 $res->content_encoding;
14 $res->content_length;
15 $res->content_type;
16 $res->cookies;
17 $res->header;
18 $res->headers;
19 $res->output;
20 $res->redirect;
21 $res->status;
22 $res->write;
23
25 This is the Catalyst Response class, which provides methods for
26 responding to the current client request. The appropriate
27 Catalyst::Engine for your environment will turn the Catalyst::Response
28 into a HTTP Response and return it to the client.
29
31 $res->body( $text | $fh | $iohandle_object )
32 $c->response->body('Catalyst rocks!');
33 Sets or returns the output (text or binary data). If you are returning
35 a large body, you might want to use a IO::Handle type of object
36 (Something that implements the getline method in the same fashion), or
37 a filehandle GLOB. These will be passed down to the PSGI handler you
38 are using and might be optimized using server specific abilities (for
39 example Twiggy will attempt to server a real local file in a non
40 blocking manner).
41 If you are using a filehandle as the body response you are responsible
43 for making sure it conforms to the PSGI specification with regards to
44 content encoding. Unlike with scalar body values or when using the
45 streaming interfaces we currently do not attempt to normalize and
46 encode your filehandle. In general this means you should be sure to be
47 sending bytes not UTF8 decoded multibyte characters.
48 Most of the time when you do:
50 open(my $fh, '<:raw', $path);
52 You should be fine. If you open a filehandle with a PerlIO layer you
54 probably are not fine. You can usually fix this by explicitly using
55 binmode to set the IOLayer to :raw. Its possible future versions of
56 Catalyst will try to 'do the right thing'.
57 When using a IO::Handle type of object and no content length has been
59 already set in the response headers Catalyst will make a reasonable
60 attempt to determine the size of the Handle. Depending on the
61 implementation of your handle object, setting the content length may
62 fail. If it is at all possible for you to determine the content length
63 of your handle object, it is recommended that you set the content
64 length in the response headers yourself, which will be respected and
65 sent by Catalyst in the response.
66 Please note that the object needs to implement "getline", not just
68 "read". Older versions of Catalyst expected your filehandle like
69 objects to do read. If you have code written for this expectation and
70 you cannot change the code to meet the PSGI specification, you can try
71 the following middleware Plack::Middleware::AdaptFilehandleRead which
72 will attempt to wrap your object in an interface that so conforms.
73 Starting from version 5.90060, when using an IO::Handle object, you may
75 want to use Plack::Middleware::XSendfile, to delegate the actual
76 serving to the frontend server. To do so, you need to pass to "body" an
77 IO object with a "path" method. This can be achieved in two ways.
78 Either using Plack::Util:
80 my $fh = IO::File->new($file, 'r');
82 Plack::Util::set_io_path($fh, $file);
83 Or using IO::File::WithPath
85 my $fh = IO::File::WithPath->new($file, 'r');
87 And then passing the filehandle to body and setting headers, if needed.
89 $c->response->body($fh);
91 $c->response->headers->content_type('text/plain');
92 $c->response->headers->content_length(-s $file);
93 $c->response->headers->last_modified((stat($file))[9]);
94 Plack::Middleware::XSendfile can be loaded in the application so:
96 __PACKAGE__->config(
98 psgi_middleware => [
99 'XSendfile',
100 # other middlewares here...
101 ],
102 );
103 Beware that loading the middleware without configuring the webserver to
105 set the request header "X-Sendfile-Type" to a supported type
106 ("X-Accel-Redirect" for nginx, "X-Sendfile" for Apache and Lighttpd),
107 could lead to the disclosure of private paths to malicious clients
108 setting that header.
109 Nginx needs the additional X-Accel-Mapping header to be set in the
111 webserver configuration, so the middleware will replace the absolute
112 path of the IO object with the internal nginx path. This is also useful
113 to prevent a buggy app to server random files from the filesystem, as
114 it's an internal redirect.
115 An nginx configuration for FastCGI could look so:
117 server {
119 server_name example.com;
120 root /my/app/root;
121 location /private/repo/ {
122 internal;
123 alias /my/app/repo/;
124 }
125 location /private/staging/ {
126 internal;
127 alias /my/app/staging/;
128 }
129 location @proxy {
130 include /etc/nginx/fastcgi_params;
131 fastcgi_param SCRIPT_NAME '';
132 fastcgi_param PATH_INFO $fastcgi_script_name;
133 fastcgi_param HTTP_X_SENDFILE_TYPE X-Accel-Redirect;
134 fastcgi_param HTTP_X_ACCEL_MAPPING /my/app=/private;
135 fastcgi_pass unix:/my/app/run/app.sock;
136 }
137 }
138 In the example above, passing filehandles with a local path matching
140 /my/app/staging or /my/app/repo will be served by nginx. Passing paths
141 with other locations will lead to an internal server error.
142 Setting the body to a filehandle without the "path" method bypasses the
144 middleware completely.
145 For Apache and Lighttpd, the mapping doesn't apply and setting the
147 X-Sendfile-Type is enough.
148 $res->has_body
150 Predicate which returns true when a body has been set.
151 $res->code
153 Alias for $res->status.
154 $res->content_encoding
156 Shortcut for $res->headers->content_encoding.
157 $res->content_length
159 Shortcut for $res->headers->content_length.
160 $res->content_type
162 Shortcut for $res->headers->content_type.
163 This value is typically set by your view or plugin. For example,
165 Catalyst::Plugin::Static::Simple will guess the mime type based on the
166 file it found, while Catalyst::View::TT defaults to "text/html".
167 $res->content_type_charset
169 Shortcut for $res->headers->content_type_charset;
170 $res->cookies
172 Returns a reference to a hash containing cookies to be set. The keys of
173 the hash are the cookies' names, and their corresponding values are
174 hash references used to construct a CGI::Simple::Cookie object.
175 $c->response->cookies->{foo} = { value => '123' };
177 The keys of the hash reference on the right correspond to the
179 CGI::Simple::Cookie parameters of the same name, except they are used
180 without a leading dash. Possible parameters are:
181 value
183 expires
184 domain
185 path
186 secure
187 httponly
188 $res->header
190 Shortcut for $res->headers->header.
191 $res->headers
193 Returns an HTTP::Headers object, which can be used to set headers.
194 $c->response->headers->header( 'X-Catalyst' => $Catalyst::VERSION );
196 $res->output
198 Alias for $res->body.
199 $res->redirect( $url, $status )
201 Causes the response to redirect to the specified URL. The default
202 status is 302.
203 $c->response->redirect( 'http://slashdot.org' );
205 $c->response->redirect( 'http://slashdot.org', 307 );
206 This is a convenience method that sets the Location header to the
208 redirect destination, and then sets the response status. You will want
209 to " return " or "$c->detach()" to interrupt the normal processing flow
210 if you want the redirect to occur straight away.
211 Note: do not give a relative URL as $url, i.e: one that is not fully
213 qualified (= "http://...", etc.) or that starts with a slash (=
214 "/path/here"). While it may work, it is not guaranteed to do the right
215 thing and is not a standard behaviour. You may opt to use uri_for() or
216 uri_for_action() instead.
217 Note: If $url is an object that does ->as_string (such as URI, which is
219 what you get from ->uri_for) we automatically call that to stringify.
220 This should ease the common case usage
221 return $c->res->redirect( $c->uri_for(...));
223 $res->location
225 Sets or returns the HTTP 'Location'.
226 $res->status
228 Sets or returns the HTTP status.
229 $c->response->status(404);
231 $res->code is an alias for this, to match HTTP::Response->code.
233 $res->write( $data )
235 Writes $data to the output stream. Calling this method will finalize
236 your headers and send the headers and status code response to the
237 client (so changing them afterwards is a waste... be sure to set your
238 headers correctly first).
239 You may call this as often as you want throughout your response cycle.
241 You may even set a 'body' afterward. So for example you might write
242 your HTTP headers and the HEAD section of your document and then set
243 the body from a template driven from a database. In some cases this
244 can seem to the client as if you had a faster overall response (but
245 note that unless your server support chunked body your content is
246 likely to get queued anyway (Starman and most other http 1.1 webservers
247 support this).
248 If there is an encoding set, we encode each line of the response (the
250 default encoding is UTF-8).
251 $res->unencoded_write( $data )
253 Works just like ->write but we don't apply any content encoding to
254 $data. Use this if you are already encoding the $data or the data is
255 arriving from an encoded storage.
256 $res->write_fh
258 Returns an instance of Catalyst::Response::Writer, which is a
259 lightweight decorator over the PSGI $writer object (see
260 PSGI.pod\Delayed-Response-and-Streaming-Body).
261 In addition to proxying the "write" and "close" method from the
263 underlying PSGI writer, this proxy object knows any application wide
264 encoding, and provides a method "write_encoded" that will properly
265 encode your written lines based upon your encoding settings. By
266 default in Catalyst responses are UTF-8 encoded and this is the
267 encoding used if you respond via "write_encoded". If you want to
268 handle encoding yourself, you can use the "write" method directly.
269 Encoding only applies to content types for which it matters. Currently
271 the following content types are assumed to need encoding: text
272 (including HTML), xml and javascript.
273 We provide access to this object so that you can properly close over it
275 for use in asynchronous and nonblocking applications. For example
276 (assuming you are using a supporting server, like Twiggy:
277 package AsyncExample::Controller::Root;
279 use Moose;
281 BEGIN { extends 'Catalyst::Controller' }
283 sub prepare_cb {
285 my $write_fh = pop;
286 return sub {
287 my $message = shift;
288 $write_fh->write("Finishing: $message\n");
289 $write_fh->close;
290 };
291 }
292 sub anyevent :Local :Args(0) {
294 my ($self, $c) = @_;
295 my $cb = $self->prepare_cb($c->res->write_fh);
296 my $watcher;
298 $watcher = AnyEvent->timer(
299 after => 5,
300 cb => sub {
301 $cb->(scalar localtime);
302 undef $watcher; # cancel circular-ref
303 });
304 }
305 Like the 'write' method, calling this will finalize headers. Unlike
307 'write' when you can this it is assumed you are taking control of the
308 response so the body is never finalized (there isn't one anyway) and
309 you need to call the close method.
310 $res->print( @data )
312 Prints @data to the output stream, separated by $,. This lets you pass
313 the response object to functions that want to write to an IO::Handle.
314 $res->finalize_headers()
316 Writes headers to response if not already written
317 from_psgi_response
319 Given a PSGI response (either three element ARRAY reference OR coderef
320 expecting a $responder) set the response from it.
321 Properly supports streaming and delayed response and / or async IO if
323 running under an expected event loop.
324 If passed an object, will expect that object to do a method "as_psgi".
326 Example:
328 package MyApp::Web::Controller::Test;
330 use base 'Catalyst::Controller';
332 use Plack::App::Directory;
333 my $app = Plack::App::Directory->new({ root => "/path/to/htdocs" })
336 ->to_app;
337 sub myaction :Local Args {
339 my ($self, $c) = @_;
340 $c->res->from_psgi_response($app->($c->req->env));
341 }
342 sub streaming_body :Local {
344 my ($self, $c) = @_;
345 my $psgi_app = sub {
346 my $respond = shift;
347 my $writer = $respond->([200,["Content-Type" => "text/plain"]]);
348 $writer->write("body");
349 $writer->close;
350 };
351 $c->res->from_psgi_response($psgi_app);
352 }
353 Please note this does not attempt to map or nest your PSGI application
355 under the Controller and Action namespace or path. You may wish to
356 review 'PSGI Helpers' under Catalyst::Utils for help in properly
357 nesting applications.
358 NOTE If your external PSGI application returns a response that has a
360 character set associated with the content type (such as "text/html;
361 charset=UTF-8") we set $c->clear_encoding to remove any additional
362 content type encoding processing later in the application (this is done
363 to avoid double encoding issues).
364 NOTE If your external PSGI application is streaming, we assume you
366 completely handle the entire jobs (including closing the stream). This
367 will also bypass the output finalization methods on Catalyst (such as
368 'finalize_body' which gets called but then skipped when it finds that
369 output is already finished.) Its possible this might cause issue with
370 some plugins that want to do 'things' during those finalization
371 methods. Just understand what is happening.
372 encodable_content_type
374 This is a regular expression used to determine of the current content
375 type should be considered encodable. Currently we apply default
376 encoding (usually UTF8) to text type contents. Here's the default
377 regular expression:
378 This would match content types like:
380 text/plain
382 text/html
383 text/xml
384 application/javascript
385 application/xml
386 application/vnd.user+xml
387 NOTE: We don't encode JSON content type responses by default since most
389 of the JSON serializers that are commonly used for this task will do so
390 automatically and we don't want to double encode. If you are not using
391 a tool like JSON to produce JSON type content, (for example you are
392 using a template system, or creating the strings manually) you will
393 need to either encoding the body yourself:
394 $c->response->body( $c->encoding->encode( $body, $c->_encode_check ) );
396 Or you can alter the regular expression using this attribute.
398 encodable_response
400 Given a Catalyst::Response return true if its one that can be encoded.
401 make sure there is an encoding set on the response
403 make sure the content type is encodable
404 make sure no content type charset has been already set to something different from the global encoding
405 make sure no content encoding is present.
406 Note this does not inspect a body since we do allow automatic encoding
408 on streaming type responses.
409 DEMOLISH
411 Ensures that the response is flushed and closed at the end of the
412 request.
413 meta
415 Provided by Moose
416
418 Catalyst Contributors, see Catalyst.pm
419
421 This library is free software. You can redistribute it and/or modify it
422 under the same terms as Perl itself.
423perl v5.34.0 2021-07-22 Catalyst::Response(3)