1POE::Component::Server:U:sHeTrTPC(o3n)tributed Perl DocuPmOeEn:t:aCtoimopnonent::Server::HTTP(3)
2
6 POE::Component::Server::HTTP - Foundation of a POE HTTP Daemon
7
9 use POE::Component::Server::HTTP;
10 use HTTP::Status;
11 my $aliases = POE::Component::Server::HTTP->new(
12 Port => 8000,
13 ContentHandler => {
14 '/' => \&handler1,
15 '/dir/' => sub { ... },
16 '/file' => sub { ... }
17 },
18 Headers => { Server => 'My Server' },
19 );
20 sub handler {
22 my ($request, $response) = @_;
23 $response->code(RC_OK);
24 $response->content("Hi, you fetched ". $request->uri);
25 return RC_OK;
26 }
27 POE::Kernel->call($aliases->{httpd}, "shutdown");
29 # next line isn't really needed
30 POE::Kernel->call($aliases->{tcp}, "shutdown");
31
33 POE::Component::Server::HTTP (PoCo::HTTPD) is a framework for building
34 custom HTTP servers based on POE. It is loosely modeled on the ideas of
35 apache and the mod_perl/Apache module.
36 It is built alot on work done by Gisle Aas on HTTP::* modules and the
38 URI module which are subclassed.
39 PoCo::HTTPD lets you register different handler, stacked by directory
41 that will be run during the cause of the request.
42 Handlers
44 Handlers are put on a stack in fifo order. The path
45 /foo/bar/baz/honk.txt will first push the handlers of / then of /foo/
46 then of /foo/bar/, then of /foo/bar/baz/, and lastly
47 /foo/bar/baz/honk.txt. Pay attention to directories! A request for
48 /honk will not match /honk/ as you are used to with apache. If you
49 want /honk to act like a directory, you should have a handler for /honk
50 which redirects to /honk/.
51 However, there can be only one ContentHandler and if any handler
53 installs a ContentHandler that will override the old ContentHandler.
54 If no handler installs a ContentHandler it will find the closest one
56 directory wise and use it.
57 There is also a special StreamHandler which is a coderef that gets
59 invoked if you have turned on streaming by doing
60 $response->streaming(1);
61 Handlers take the $request and $response objects as arguments.
63 RC_OK
65 Everything is ok, please continue processing.
66 RC_DENY
68 If it is a TransHandler, stop translation handling and carry on
69 with a PreHandler, if it is a PostHandler do nothing, else return
70 denied to the client.
71 RC_WAIT
73 This is a special handler that suspends the execution of the
74 handlers. They will be suspended until $response->continue() is
75 called, this is usefull if you want to do a long request and not
76 blocck.
77 The following handlers are available.
79 TransHandler
81 TransHandlers are run before the URI has been resolved, giving them
82 a chance to change the URI. They can therefore not be registred per
83 directory.
84 new(TransHandler => [ sub {return RC_OK} ]);
86 A TransHandler can stop the dispatching of TransHandlers and jump
88 to the next handler type by specifing RC_DENY;
89 PreHandler
91 PreHandlers are stacked by directory and run after TransHandler but
92 before the ContentHandler. They can change ContentHandler (but
93 beware, other PreHandlers might also change it) and push on
94 PostHandlers.
95 new(PreHandler => { '/' => [sub {}], '/foo/' => [\&foo]});
97 ContentHandler
99 The handler that is supposed to give the content. When this handler
100 returns it will send the response object to the client. It will
101 automaticly add Content-Length and Date if these are not set. If
102 the response is streaming it will make sure the correct headers are
103 set. It will also expand any cookies which have been pushed onto
104 the response object.
105 new(ContentHandler => { '/' => sub {}, '/foo/' => \&foo});
107 ErrorHandler
109 This handler is called when there is a read or write error on the
110 socket. This is most likely caused by the remote side closing the
111 connection. $resquest->is_error and $response->is_error will
112 return true. Note that "PostHanlder" will still called, but
113 "TransHandler" and "PreHandler" won't be. It is a map to coderefs
114 just like ContentHandler is.
115 PostHandler
117 These handlers are run after the socket has been flushed.
118 new(PostHandler => { '/' => [sub {}], '/foo/' => [\&foo]});
120 StreamHandler
122 If you turn on streaming in any other handler, the request is
123 placed in streaming mode. This handler is called, with the usual
124 parameters, when streaming mode is first entered, and subsequently
125 when each block of data is flushed to the client.
126 Streaming mode is turned on via the $response object:
128 $response->streaming(1);
130 You deactivate streaming mode with the same object:
132 $response->close;
134 Content is also sent to the client via the $response object:
136 $response->send($somedata);
138 The output filter is set to POE::Filter::Stream, which passes the
140 data through unchanged. If you are doing a multipart/mixed
141 response, you will have to set up your own headers.
142 Example:
144 sub new {
146 .....
147 POE::Component::Filter::HTTP->new(
148 ContentHandler => { '/someurl' => sub { $self->someurl(@_) },
149 StreamHandler => sub { $self->stream(@_),
150 );
151 }
152 sub someurl {
154 my($self, $resquest, $response)=@_;
155 $self->{todo} = [ .... ];
156 $response->streaming(1);
157 $response->code(RC_OK); # you must set up your response header
158 $response->content_type(...);
159 return RC_OK;
161 }
162 sub stream {
164 my($self, $resquest, $response)=@_;
165 if( @{$self->{todo}} ) {
167 $response->send(shift @{$self->{todo}});
168 }
169 else {
170 $response->close;
171 }
172 }
173 Another example can be found in t/30_stream.t. The parts dealing
175 with multipart/mixed are well documented and at the end of the
176 file.
177 NOTE: Changes in streaming mode are only verified when
179 StreamHandler exits. So you must either turn streaming off in your
180 StreamHandler, or make sure that the StreamHandler will be called
181 again. This last is done by sending data to the client. If for
182 some reason you have no data to send, you can get the same result
183 with "continue". Remember that this will also cause the
184 StreamHandler to be called one more time.
185 my $aliases=POE::Component::Filter::HTTP->new( ....);
187 # and then, when the end of the stream in met
189 $response->close;
190 $response->continue;
191 NOTE: even when the stream ends, the client connection will be held
193 open if Keepalive is active. To force the connection closed, set
194 the Connection header to close:
195 $resquest->header(Connection => 'close');
197 This might be a bug. Are there any cases where we'd want to keep
199 the connection open after a stream?
200
202 The "shutdown" event may be sent to the component indicating that it
203 should shut down. The event may be sent using the return value of the
204 new() method (which is a session id) by either post()ing or call()ing.
205 I've experienced some problems with the session not receiving the event
207 when it gets post()ed so call() is advised.
208
210 Please also take a look at HTTP::Response, HTTP::Request, URI, POE and
211 POE::Filter::HTTPD
212
214 Document Connection Response and Request objects.
215 Write more tests
216 Add a PoCo::Server::HTTP::Session that matches a http session against
217 poe session using cookies or other state system
218 Add more options to streaming
219 Figure out why post()ed "shutdown" events don't get received.
220 Probably lots of other API changes
221
223 Arthur Bergman, arthur@contiller.se
224 Additional hacking by Philip Gwyn, poe-at-pied.nu
226 Released under the same terms as POE.
228perl v5.30.0 2019-07-26 POE::Component::Server::HTTP(3)