|
|
HTTP::Request::Common - Construct common HTTP::Request objects
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]);
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:
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 ...).
Like GET() but the method in the request is ``HEAD''.
The head(...) method of ``LWP::UserAgent'' exists as a shortcut for
$ua->request(HEAD ...).
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.
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 a 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 a 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 a 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 ...).
the HTTP::Request manpage, the LWP::UserAgent manpage
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.