XML::Atom::Server(3) User Contributed Perl Documentation XML::Atom::Server(3)NAMEXML::Atom::Server - A server for the Atom API
SYNOPSIS
package My::Server;
use base qw( XML::Atom::Server );
sub handle_request {
my $server = shift;
$server->authenticate or return;
my $method = $server->request_method;
if ($method eq 'POST') {
return $server->new_post;
}
...
}
my %Passwords;
sub password_for_user {
my $server = shift;
my($username) = @_;
$Passwords{$username};
}
sub new_post {
my $server = shift;
my $entry = $server->atom_body or return;
## $entry is an XML::Atom::Entry object.
## ... Save the new entry ...
}
package main;
my $server = My::Server->new;
$server->run;
DESCRIPTIONXML::Atom::Server provides a base class for Atom API servers. It
handles all core server processing, both the SOAP and REST formats of
the protocol, and WSSE authentication. It can also run as either a
mod_perl handler or as part of a CGI program.
It does not provide functions specific to any particular
implementation, such as posting an entry, retrieving a list of entries,
deleting an entry, etc. Implementations should subclass
XML::Atom::Server, overriding the handle_request method, and handle all
functions such as this themselves.
SUBCLASSING
Request Handling
Subclasses of XML::Atom::Server must override the handle_request method
to perform all request processing. The implementation must set all
response headers, including the response code and any relevant HTTP
headers, and should return a scalar representing the response body to
be sent back to the client.
For example:
sub handle_request {
my $server = shift;
my $method = $server->request_method;
if ($method eq 'POST') {
return $server->new_post;
}
## ... handle GET, PUT, etc
}
sub new_post {
my $server = shift;
my $entry = $server->atom_body or return;
my $id = save_this_entry($entry); ## Implementation-specific
$server->response_header(Location => $server->uri . '/entry_id=' . $id);
$server->response_code(201);
$server->response_content_type('application/x.atom+xml');
return serialize_entry($entry); ## Implementation-specific
}
Authentication
Servers that require authentication for posting or retrieving entries
or feeds should override the password_for_user method. Given a username
(from the WSSE header), password_for_user should return that user's
password in plaintext. This will then be combined with the nonce and
the creation time to generate the digest, which will be compared with
the digest sent in the WSSE header. If the supplied username doesn't
exist in your user database or alike, just return "undef".
For example:
my %Passwords = ( foo => 'bar' ); ## The password for "foo" is "bar".
sub password_for_user {
my $server = shift;
my($username) = @_;
$Passwords{$username};
}
METHODSXML::Atom::Server provides a variety of methods to be used by
subclasses for retrieving headers, content, and other request
information, and for setting the same on the response.
Client Request Parameters
· $server->uri
Returns the URI of the Atom server implementation.
· $server->request_method
Returns the name of the request method sent to the server from the
client (for example, "GET", "POST", etc). Note that if the client
sent the request in a SOAP envelope, the method is obtained from
the SOAPAction HTTP header.
· $server->request_header($header)
Retrieves the value of the HTTP request header $header.
· $server->request_content
Returns a scalar containing the contents of a POST or PUT request
from the client.
· $server->request_param($param)
XML::Atom::Server automatically parses the PATH_INFO sent in the
request and breaks it up into key-value pairs. This can be used to
pass parameters. For example, in the URI
http://localhost/atom-server/entry_id=1
the entry_id parameter would be set to 1.
request_param returns the value of the value of the parameter
$param.
Setting up the Response
· $server->response_header($header, $value)
Sets the value of the HTTP response header $header to $value.
· $server->response_code([ $code ])
Returns the current response code to be sent back to the client,
and if $code is given, sets the response code.
· $server->response_content_type([ $type ])
Returns the current Content-Type header to be sent back to the
client, and $type is given, sets the value for that header.
Processing the Request
· $server->authenticate
Attempts to authenticate the request based on the authentication
information present in the request (currently just WSSE). This will
call the password_for_user method in the subclass to obtain the
cleartext password for the username given in the request.
· $server->atom_body
Returns an XML::Atom::Entry object containing the entry sent in the
request.
USAGE
Once you have defined your server subclass, you can set it up either as
a CGI program or as a mod_perl handler.
A simple CGI program would look something like this:
#!/usr/bin/perl -w
use strict;
use My::Server;
my $server = My::Server->new;
$server->run;
A simple mod_perl handler configuration would look something like this:
PerlModule My::Server
<Location /atom-server>
SetHandler perl-script
PerlHandler My::Server
</Location>
ERROR HANDLING
If you wish to return an error from handle_request, you can use the
built-in error method:
sub handle_request {
my $server = shift;
...
return $server->error(500, "Something went wrong");
}
This will be returned to the client with a response code of 500 and an
error string of "Something went wrong". Errors are automatically
serialized into SOAP faults if the incoming request is enclosed in a
SOAP envelope.
AUTHOR & COPYRIGHT
Please see the XML::Atom manpage for author, copyright, and license
information.
perl v5.14.1 2011-06-08 XML::Atom::Server(3)
