[ViewVC] Contents of: cvs/AnyEvent-HTTP/README

NAME
    AnyEvent::HTTP - simple but non-blocking HTTP/HTTPS client

SYNOPSIS
       use AnyEvent::HTTP;

       http_get "http://www.nethype.de/", sub { print $_[1] };

       # ... do something else here

DESCRIPTION
    This module is an AnyEvent user, you need to make sure that you use and
    run a supported event loop.

    This module implements a simple, stateless and non-blocking HTTP client.
    It supports GET, POST and other request methods, cookies and more, all
    on a very low level. It can follow redirects supports proxies and
    automatically limits the number of connections to the values specified
    in the RFC.

    It should generally be a "good client" that is enough for most HTTP
    tasks. Simple tasks should be simple, but complex tasks should still be
    possible as the user retains control over request and response headers.

    The caller is responsible for authentication management, cookies (if the
    simplistic implementation in this module doesn't suffice), referer and
    other high-level protocol details for which this module offers only
    limited support.

  METHODS
    http_get $url, key => value..., $cb->($data, $headers)
        Executes an HTTP-GET request. See the http_request function for
        details on additional parameters and the return value.

    http_head $url, key => value..., $cb->($data, $headers)
        Executes an HTTP-HEAD request. See the http_request function for
        details on additional parameters and the return value.

    http_post $url, $body, key => value..., $cb->($data, $headers)
        Executes an HTTP-POST request with a request body of $body. See the
        http_request function for details on additional parameters and the
        return value.

    http_request $method => $url, key => value..., $cb->($data, $headers)
        Executes a HTTP request of type $method (e.g. "GET", "POST"). The
        URL must be an absolute http or https URL.

        When called in void context, nothing is returned. In other contexts,
        "http_request" returns a "cancellation guard" - you have to keep the
        object at least alive until the callback get called. If the object
        gets destroyed before the callbakc is called, the request will be
        cancelled.

        The callback will be called with the response data as first argument
        (or "undef" if it wasn't available due to errors), and a hash-ref
        with response headers as second argument.

        All the headers in that hash are lowercased. In addition to the
        response headers, the "pseudo-headers" "HTTPVersion", "Status" and
        "Reason" contain the three parts of the HTTP Status-Line of the same
        name. The pseudo-header "URL" contains the original URL (which can
        differ from the requested URL when following redirects).

        If the server sends a header multiple times, then their contents
        will be joined together with a comma (","), as per the HTTP spec.

        If an internal error occurs, such as not being able to resolve a
        hostname, then $data will be "undef", "$headers->{Status}" will be
        599 and the "Reason" pseudo-header will contain an error message.

        A typical callback might look like this:

           sub {
              my ($body, $hdr) = @_;

              if ($hdr->{Status} =~ /^2/) {
                 ... everything should be ok
              } else {
                 print "error, $hdr->{Status} $hdr->{Reason}\n";
              }
           }

        Additional parameters are key-value pairs, and are fully optional.
        They include:

        recurse => $count (default: $MAX_RECURSE)
            Whether to recurse requests or not, e.g. on redirects,
            authentication retries and so on, and how often to do so.

        headers => hashref
            The request headers to use. Currently, "http_request" may
            provide its own "Host:", "Content-Length:", "Connection:" and
            "Cookie:" headers and will provide defaults for "User-Agent:"
            and "Referer:".

        timeout => $seconds
            The time-out to use for various stages - each connect attempt
            will reset the timeout, as will read or write activity. Default
            timeout is 5 minutes.

        proxy => [$host, $port[, $scheme]] or undef
            Use the given http proxy for all requests. If not specified,
            then the default proxy (as specified by $ENV{http_proxy}) is
            used.

            $scheme must be either missing or "http" for HTTP, or "https"
            for HTTPS.

        body => $string
            The request body, usually empty. Will be-sent as-is (future
            versions of this module might offer more options).

        cookie_jar => $hash_ref
            Passing this parameter enables (simplified) cookie-processing,
            loosely based on the original netscape specification.

            The $hash_ref must be an (initially empty) hash reference which
            will get updated automatically. It is possible to save the
            cookie_jar to persistent storage with something like JSON or
            Storable, but this is not recommended, as expire times are
            currently being ignored.

            Note that this cookie implementation is not of very high
            quality, nor meant to be complete. If you want complete cookie
            management you have to do that on your own. "cookie_jar" is
            meant as a quick fix to get some cookie-using sites working.
            Cookies are a privacy disaster, do not use them unless required
            to.

        Example: make a simple HTTP GET request for http://www.nethype.de/

           http_request GET => "http://www.nethype.de/", sub {
              my ($body, $hdr) = @_;
              print "$body\n";
           };

        Example: make a HTTP HEAD request on https://www.google.com/, use a
        timeout of 30 seconds.

           http_request
              GET     => "https://www.google.com",
              timeout => 30,
              sub {
                 my ($body, $hdr) = @_;
                 use Data::Dumper;
                 print Dumper $hdr;
              }
           ;

        Example: make another simple HTTP GET request, but immediately try
        to cancel it.

           my $request = http_request GET => "http://www.nethype.de/", sub {
              my ($body, $hdr) = @_;
              print "$body\n";
           };

           undef $request;

  GLOBAL FUNCTIONS AND VARIABLES
    AnyEvent::HTTP::set_proxy "proxy-url"
        Sets the default proxy server to use. The proxy-url must begin with
        a string of the form "http://host:port" (optionally "https:...").

    $AnyEvent::HTTP::MAX_RECURSE
        The default value for the "recurse" request parameter (default: 10).

    $AnyEvent::HTTP::USERAGENT
        The default value for the "User-Agent" header (the default is
        "Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION;
        +http://software.schmorp.de/pkg/AnyEvent)").

    $AnyEvent::HTTP::MAX_PERSISTENT
        The maximum number of persistent connections to keep open (default:
        8).

        Not implemented currently.

    $AnyEvent::HTTP::PERSISTENT_TIMEOUT
        The maximum time to cache a persistent connection, in seconds
        (default: 2).

        Not implemented currently.

    $AnyEvent::HTTP::ACTIVE
        The number of active connections. This is not the number of
        currently running requests, but the number of currently open and
        non-idle TCP connections. This number of can be useful for
        load-leveling.

SEE ALSO
    AnyEvent.

AUTHOR
       Marc Lehmann <schmorp@schmorp.de>
       http://home.schmorp.de/

    With many thanks to Дмитрий Шалашов, who provided
    countless testcases and bugreports.

Revision:	1.7
Committed:	Fri Nov 21 08:20:14 2008 UTC (15 years, 6 months ago) by root
Branch:	MAIN
CVS Tags:	rel-1_11, rel-1_12
Changes since 1.6:	+3 -0 lines
Log Message:	1.11
#	Content
1	NAME
2	AnyEvent::HTTP - simple but non-blocking HTTP/HTTPS client
3
4	SYNOPSIS
5	use AnyEvent::HTTP;
6
7	http_get "http://www.nethype.de/", sub { print $_[1] };
8
9	# ... do something else here
10
11	DESCRIPTION
12	This module is an AnyEvent user, you need to make sure that you use and
13	run a supported event loop.
14
15	This module implements a simple, stateless and non-blocking HTTP client.
16	It supports GET, POST and other request methods, cookies and more, all
17	on a very low level. It can follow redirects supports proxies and
18	automatically limits the number of connections to the values specified
19	in the RFC.
20
21	It should generally be a "good client" that is enough for most HTTP
22	tasks. Simple tasks should be simple, but complex tasks should still be
23	possible as the user retains control over request and response headers.
24
25	The caller is responsible for authentication management, cookies (if the
26	simplistic implementation in this module doesn't suffice), referer and
27	other high-level protocol details for which this module offers only
28	limited support.
29
30	METHODS
31	http_get $url, key => value..., $cb->($data, $headers)
32	Executes an HTTP-GET request. See the http_request function for
33	details on additional parameters and the return value.
34
35	http_head $url, key => value..., $cb->($data, $headers)
36	Executes an HTTP-HEAD request. See the http_request function for
37	details on additional parameters and the return value.
38
39	http_post $url, $body, key => value..., $cb->($data, $headers)
40	Executes an HTTP-POST request with a request body of $body. See the
41	http_request function for details on additional parameters and the
42	return value.
43
44	http_request $method => $url, key => value..., $cb->($data, $headers)
45	Executes a HTTP request of type $method (e.g. "GET", "POST"). The
46	URL must be an absolute http or https URL.
47
48	When called in void context, nothing is returned. In other contexts,
49	"http_request" returns a "cancellation guard" - you have to keep the
50	object at least alive until the callback get called. If the object
51	gets destroyed before the callbakc is called, the request will be
52	cancelled.
53
54	The callback will be called with the response data as first argument
55	(or "undef" if it wasn't available due to errors), and a hash-ref
56	with response headers as second argument.
57
58	All the headers in that hash are lowercased. In addition to the
59	response headers, the "pseudo-headers" "HTTPVersion", "Status" and
60	"Reason" contain the three parts of the HTTP Status-Line of the same
61	name. The pseudo-header "URL" contains the original URL (which can
62	differ from the requested URL when following redirects).
63
64	If the server sends a header multiple times, then their contents
65	will be joined together with a comma (","), as per the HTTP spec.
66
67	If an internal error occurs, such as not being able to resolve a
68	hostname, then $data will be "undef", "$headers->{Status}" will be
69	599 and the "Reason" pseudo-header will contain an error message.
70
71	A typical callback might look like this:
72
73	sub {
74	my ($body, $hdr) = @_;
75
76	if ($hdr->{Status} =~ /^2/) {
77	... everything should be ok
78	} else {
79	print "error, $hdr->{Status} $hdr->{Reason}\n";
80	}
81	}
82
83	Additional parameters are key-value pairs, and are fully optional.
84	They include:
85
86	recurse => $count (default: $MAX_RECURSE)
87	Whether to recurse requests or not, e.g. on redirects,
88	authentication retries and so on, and how often to do so.
89
90	headers => hashref
91	The request headers to use. Currently, "http_request" may
92	provide its own "Host:", "Content-Length:", "Connection:" and
93	"Cookie:" headers and will provide defaults for "User-Agent:"
94	and "Referer:".
95
96	timeout => $seconds
97	The time-out to use for various stages - each connect attempt
98	will reset the timeout, as will read or write activity. Default
99	timeout is 5 minutes.
100
101	proxy => [$host, $port[, $scheme]] or undef
102	Use the given http proxy for all requests. If not specified,
103	then the default proxy (as specified by $ENV{http_proxy}) is
104	used.
105
106	$scheme must be either missing or "http" for HTTP, or "https"
107	for HTTPS.
108
109	body => $string
110	The request body, usually empty. Will be-sent as-is (future
111	versions of this module might offer more options).
112
113	cookie_jar => $hash_ref
114	Passing this parameter enables (simplified) cookie-processing,
115	loosely based on the original netscape specification.
116
117	The $hash_ref must be an (initially empty) hash reference which
118	will get updated automatically. It is possible to save the
119	cookie_jar to persistent storage with something like JSON or
120	Storable, but this is not recommended, as expire times are
121	currently being ignored.
122
123	Note that this cookie implementation is not of very high
124	quality, nor meant to be complete. If you want complete cookie
125	management you have to do that on your own. "cookie_jar" is
126	meant as a quick fix to get some cookie-using sites working.
127	Cookies are a privacy disaster, do not use them unless required
128	to.
129
130	Example: make a simple HTTP GET request for http://www.nethype.de/
131
132	http_request GET => "http://www.nethype.de/", sub {
133	my ($body, $hdr) = @_;
134	print "$body\n";
135	};
136
137	Example: make a HTTP HEAD request on https://www.google.com/, use a
138	timeout of 30 seconds.
139
140	http_request
141	GET => "https://www.google.com",
142	timeout => 30,
143	sub {
144	my ($body, $hdr) = @_;
145	use Data::Dumper;
146	print Dumper $hdr;
147	}
148	;
149
150	Example: make another simple HTTP GET request, but immediately try
151	to cancel it.
152
153	my $request = http_request GET => "http://www.nethype.de/", sub {
154	my ($body, $hdr) = @_;
155	print "$body\n";
156	};
157
158	undef $request;
159
160	GLOBAL FUNCTIONS AND VARIABLES
161	AnyEvent::HTTP::set_proxy "proxy-url"
162	Sets the default proxy server to use. The proxy-url must begin with
163	a string of the form "http://host:port" (optionally "https:...").
164
165	$AnyEvent::HTTP::MAX_RECURSE
166	The default value for the "recurse" request parameter (default: 10).
167
168	$AnyEvent::HTTP::USERAGENT
169	The default value for the "User-Agent" header (the default is
170	"Mozilla/5.0 (compatible; AnyEvent::HTTP/$VERSION;
171	+http://software.schmorp.de/pkg/AnyEvent)").
172
173	$AnyEvent::HTTP::MAX_PERSISTENT
174	The maximum number of persistent connections to keep open (default:
175	8).
176
177	Not implemented currently.
178
179	$AnyEvent::HTTP::PERSISTENT_TIMEOUT
180	The maximum time to cache a persistent connection, in seconds
181	(default: 2).
182
183	Not implemented currently.
184
185	$AnyEvent::HTTP::ACTIVE
186	The number of active connections. This is not the number of
187	currently running requests, but the number of currently open and
188	non-idle TCP connections. This number of can be useful for
189	load-leveling.
190
191	SEE ALSO
192	AnyEvent.
193
194	AUTHOR
195	Marc Lehmann <schmorp@schmorp.de>
196	http://home.schmorp.de/
197
198	With many thanks to Дмитрий Шалашов, who provided
199	countless testcases and bugreports.
200