NAME

Net::Curl::Form - Form builder for Net::Curl

SYNOPSIS

 use Net::Curl::Form qw(:constants);

 my $form = Net::Curl::Form->new();
 $form->add(
     CURLFORM_COPYNAME() => $name,
     CURLFORM_COPYCONTENTS() => $data
 );
 $form->add(
     CURLFORM_COPYNAME() => $filename,
     CURLFORM_FILE() => $filename
 );


 # most likely use:
 $easy->setopt( CURLOPT_HTTPPOST() => $form );

 # serialize
 my $serial = $form->get();

DESCRIPTION

This module lets you build multipart/form-data HTTP POST. When finished it can be either supplied to Net::Curl::Easy handle or serialized manually. Net::Curl::Form does not export by default anything, but constants can be exported upon request.

 use Net::Curl::Form qw(:constants);

CONSTRUCTOR

new( [BASE] )

Creates new Net::Curl::Form object. If BASE is specified it will be used as object base, otherwise an empty hash will be used. BASE must be a valid reference which has not been blessed already. It will not be used by the object.

 my $form = Net::Curl::Form->new( [qw(my very private data)] );

METHODS

add( CURLFORM_option => DATA, ... )

Adds new section to form object. See curl_formadd(3) <https://curl.haxx.se/libcurl/c/curl_formadd.html> for more info.

Unlike in libcurl function, there is no need to add CURLFORM_END as the last argument.

On error this method dies with "Net::Curl::Form::Code" error object.

Buffer and name options automatibally set their length values so there is no need to set length even if there is a NUL character in the data. If you want to shorten the buffer CURLFORM_*LENGTH options must be set inmediatelly after their buffer option, otherwise an CURL_FORMADD_OPTION_TWICE exception will occur.

 $form->add(
     CURLFORM_COPYNAME() => "name",
     CURLFORM_COPYCONTENTS() => "content\0binary"
 );
 $form->add(
     CURLFORM_PTRNAME() => "name",
     CURLFORM_NAMELENGTH() => 2,
     CURLFORM_PTRCONTENTS() => "content",
     CURLFORM_CONTENTSLENGTH() => 4,
 );
 $form->add(
     CURLFORM_COPYNAME, "htmlcode",
     CURLFORM_COPYCONTENTS, "<HTML></HTML>",
     CURLFORM_CONTENTTYPE, "text/html"
 );
 $form->add(
     CURLFORM_COPYNAME, "picture",
     CURLFORM_FILE, "my-face.jpg"
 );
 $form->add(
     CURLFORM_COPYNAME, "picture",
     CURLFORM_FILE, "my-face.jpg",
     CURLFORM_CONTENTTYPE, "image/jpeg"
 );
 $form->add(
     CURLFORM_COPYNAME, "picture",
     CURLFORM_FILE, "my-face.jpg",
     CURLFORM_FILE, "your-face.jpg",
 );
 $form->add(
     CURLFORM_COPYNAME, "filecontent",
     CURLFORM_FILECONTENT, ".bashrc"
 );

get( [BUFFER / FH / USERDATA], [CALLBACK] )

Use it to serialize the form object. Normally there is no need to use it because Net::Curl::Easy will serialize it while uploading data.

There are multiple ways to perform serialization:

direct

With no arguments a scalar is returned.

 my $serial = $form->get();

write to file handle

If there is only one argument and it is a GLOB or a GLOB reference, serialized contents will be written to that file handle.

 open my $file, ">", "post.txt";
 $form->get( $file );

write to buffer

If there is only one argument and it is writable, serialized contents will be concatenated to it.

 my $serial;
 $form->get( $serial );

 # same as above
 $form->get( \$serial );

use a callback

With two arguments, second one must be a function that will be called for serialization. First argument is a user data that will be passed to that function.

The callback will receive three arguments: form object, data buffer and user data. It must return the length of the data buffer, otherwise serialization will be aborted.

 sub cb_serial
 {
     my ( $form, $data, $uservar ) = @_;

     # do anything you want

     return length $data;
 }
 $form->get( "userdata", \&cb_serial );

Calls curl_formget(3) <https://curl.haxx.se/libcurl/c/curl_formget.html>. Rethrows exceptions from callbacks.

FUNCTIONS

None of those functions are exported, you must use fully qualified names.

strerror( [WHATEVER], CODE )

Return a string for error code CODE. String is extracted from error constant name.

 my $message = Net::Curl::Form->strerror(
     Net::Curl::Form::CURL_FORMADD_OPTION_TWICE
 );

CONSTANTS

CURLFORM_*: Most of those constants can be used in add() method. Currently CURLFORM_STREAM and CURLFORM_ARRAY are not supported. Others will behave in the way described in curl_formadd(3) <https://curl.haxx.se/libcurl/c/curl_formadd.html>.
CURL_FORMADD_*: If add() fails it will return one of those values.

CALLBACKS

Callback for get() is described already in "use a callback" subsection.

Net::Curl::Form::Code

Net::Curl::Form add() method on failure throws a Net::Curl::Form::Code error object. It has both numeric value and, when used as string, it calls strerror() function to display a nice message.

COPYRIGHT

You may opt to use, copy, modify, merge, publish, distribute and/or sell copies of the Software, and permit persons to whom the Software is furnished to do so, under the terms of the MPL or the MIT/X-derivate licenses. You may pick one of these licenses.