NAME¶
HTTP::Request::Common - Construct common HTTP::Request objects
SYNOPSIS¶
use HTTP::Request::Common;
$ua = LWP::UserAgent->new;
$ua->request(GET 'http://www.sn.no/');
$ua->request(POST 'http://somewhere/foo', [foo => bar, bar => foo]);
DESCRIPTION¶
This module provide functions that return newly created
"HTTP::Request" objects. These functions are usually more convenient
to use than the standard "HTTP::Request" constructor for the most
common requests. The following functions are provided:
- GET $url
- GET $url, Header => Value,...
- The GET() function returns an
"HTTP::Request" object initialized with the "GET"
method and the specified URL. It is roughly equivalent to the following
call
HTTP::Request->new(
GET => $url,
HTTP::Headers->new(Header => Value,...),
)
but is less cluttered. What is different is that a header named
"Content" will initialize the content part of the request
instead of setting a header field. Note that GET requests should normally
not have a content, so this hack makes more sense for the PUT() and
POST() functions described below.
The get(...) method of "LWP::UserAgent" exists as a shortcut for
$ua->request(GET ...).
- HEAD $url
- HEAD $url, Header => Value,...
- Like GET() but the method in the request is
"HEAD".
The head(...) method of "LWP::UserAgent" exists as a shortcut for
$ua->request(HEAD ...).
- PUT $url
- PUT $url, Header => Value,...
- PUT $url, Header => Value,..., Content =>
$content
- Like GET() but the method in the request is
"PUT".
The content of the request can be specified using the "Content"
pseudo-header. This steals a bit of the header field namespace as there is
no way to directly specify a header that is actually called
"Content". If you really need this you must update the request
returned in a separate statement.
- DELETE $url
- DELETE $url, Header => Value,...
- Like GET() but the method in the request is
"DELETE". This function is not exported by default.
- POST $url
- POST $url, Header => Value,...
- POST $url, $form_ref, Header => Value,...
- POST $url, Header => Value,..., Content =>
$form_ref
- POST $url, Header => Value,..., Content =>
$content
- This works mostly like PUT() with "POST"
as the method, but this function also takes a second optional array or
hash reference parameter $form_ref. As for PUT() the content can
also be specified directly using the "Content" pseudo-header,
and you may also provide the $form_ref this way.
The $form_ref argument can be used to pass key/value pairs for the form
content. By default we will initialize a request using the
"application/x-www-form-urlencoded" content type. This means
that you can emulate an HTML <form> POSTing like this:
POST 'http://www.perl.org/survey.cgi',
[ name => 'Gisle Aas',
email => 'gisle@aas.no',
gender => 'M',
born => '1964',
perc => '3%',
];
This will create an HTTP::Request object that looks like this:
POST http://www.perl.org/survey.cgi
Content-Length: 66
Content-Type: application/x-www-form-urlencoded
name=Gisle%20Aas&email=gisle%40aas.no&gender=M&born=1964&perc=3%25
Multivalued form fields can be specified by either repeating the field name
or by passing the value as an array reference.
The POST method also supports the "multipart/form-data" content
used for Form-based File Upload as specified in RFC 1867. You
trigger this content format by specifying a content type of 'form-data' as
one of the request headers. If one of the values in the $form_ref is an
array reference, then it is treated as a file part specification with the
following interpretation:
[ $file, $filename, Header => Value... ]
[ undef, $filename, Header => Value,..., Content => $content ]
The first value in the array ($file) is the name of a file to open. This
file will be read and its content placed in the request. The routine will
croak if the file can't be opened. Use an "undef" as $file value
if you want to specify the content directly with a "Content"
header. The $filename is the filename to report in the request. If this
value is undefined, then the basename of the $file will be used. You can
specify an empty string as $filename if you want to suppress sending the
filename when you provide a $file value.
If a $file is provided by no "Content-Type" header, then
"Content-Type" and "Content-Encoding" will be filled
in automatically with the values returned by
LWP::MediaTypes::guess_media_type()
Sending my ~/.profile to the survey used as example above can be
achieved by this:
POST 'http://www.perl.org/survey.cgi',
Content_Type => 'form-data',
Content => [ name => 'Gisle Aas',
email => 'gisle@aas.no',
gender => 'M',
born => '1964',
init => ["$ENV{HOME}/.profile"],
]
This will create an HTTP::Request object that almost looks this (the
boundary and the content of your ~/.profile is likely to be
different):
POST http://www.perl.org/survey.cgi
Content-Length: 388
Content-Type: multipart/form-data; boundary="6G+f"
--6G+f
Content-Disposition: form-data; name="name"
Gisle Aas
--6G+f
Content-Disposition: form-data; name="email"
gisle@aas.no
--6G+f
Content-Disposition: form-data; name="gender"
M
--6G+f
Content-Disposition: form-data; name="born"
1964
--6G+f
Content-Disposition: form-data; name="init"; filename=".profile"
Content-Type: text/plain
PATH=/local/perl/bin:$PATH
export PATH
--6G+f--
If you set the $DYNAMIC_FILE_UPLOAD variable (exportable) to some TRUE
value, then you get back a request object with a subroutine closure as the
content attribute. This subroutine will read the content of any files on
demand and return it in suitable chunks. This allow you to upload
arbitrary big files without using lots of memory. You can even upload
infinite files like /dev/audio if you wish; however, if the file is
not a plain file, there will be no Content-Length header defined for the
request. Not all servers (or server applications) like this. Also, if the
file(s) change in size between the time the Content-Length is calculated
and the time that the last chunk is delivered, the subroutine will
"Croak".
The post(...) method of "LWP::UserAgent" exists as a shortcut for
$ua->request(POST ...).
SEE ALSO¶
HTTP::Request, LWP::UserAgent
COPYRIGHT¶
Copyright 1997-2004, Gisle Aas
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.