Byrne Reese > SOAP-Lite-0.69 > SOAP::Transport::HTTP

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NAME ^

SOAP::Transport::HTTP - Server/Client side HTTP support for SOAP::Lite

SYNOPSIS ^

Client
  use SOAP::Lite 
    uri => 'http://my.own.site.com/My/Examples',
    proxy => 'http://localhost/', 
  # proxy => 'http://localhost/cgi-bin/soap.cgi', # local CGI server
  # proxy => 'http://localhost/',                 # local daemon server
  # proxy => 'http://localhost/soap',             # local mod_perl server
  # proxy => 'https://localhost/soap',            # local mod_perl SECURE server
  # proxy => 'http://login:password@localhost/cgi-bin/soap.cgi', # local CGI server with authentication
  ;

  print getStateName(1);
CGI server
  use SOAP::Transport::HTTP;

  SOAP::Transport::HTTP::CGI
    # specify path to My/Examples.pm here
    -> dispatch_to('/Your/Path/To/Deployed/Modules', 'Module::Name', 'Module::method') 
    -> handle
  ;
Daemon server
  use SOAP::Transport::HTTP;

  # change LocalPort to 81 if you want to test it with soapmark.pl

  my $daemon = SOAP::Transport::HTTP::Daemon
    -> new (LocalAddr => 'localhost', LocalPort => 80)
    # specify list of objects-by-reference here 
    -> objects_by_reference(qw(My::PersistentIterator My::SessionIterator My::Chat))
    # specify path to My/Examples.pm here
    -> dispatch_to('/Your/Path/To/Deployed/Modules', 'Module::Name', 'Module::method') 
  ;
  print "Contact to SOAP server at ", $daemon->url, "\n";
  $daemon->handle;
Apache mod_perl server

See examples/server/Apache.pm and "EXAMPLES" section for more information.

mod_soap server (.htaccess, directory-based access)
  SetHandler perl-script
  PerlHandler Apache::SOAP
  PerlSetVar dispatch_to "/Your/Path/To/Deployed/Modules, Module::Name, Module::method"
  PerlSetVar options "compress_threshold => 10000"

See Apache::SOAP for more information.

DESCRIPTION ^

This class encapsulates all HTTP related logic for a SOAP server, independent of what web server it's attached to. If you want to use this class you should follow simple guideline mentioned above.

Following methods are available:

on_action()

on_action method lets you specify SOAPAction understanding. It accepts reference to subroutine that takes three parameters:

  SOAPAction, method_uri and method_name. 

SOAPAction is taken from HTTP header and method_uri and method_name are extracted from request's body. Default behavior is match SOAPAction if present and ignore it otherwise. You can specify you own, for example die if SOAPAction doesn't match with following code:

  $server->on_action(sub {
    (my $action = shift) =~ s/^("?)(.+)\1$/$2/;
    die "SOAPAction shall match 'uri#method'\n" if $action ne join '#', @_;
  });
dispatch_to()

dispatch_to lets you specify where you want to dispatch your services to. More precisely, you can specify PATH, MODULE, method or combination MODULE::method. Example:

  dispatch_to( 
    'PATH/',          # dynamic: load anything from there, any module, any method
    'MODULE',         # static: any method from this module 
    'MODULE::method', # static: specified method from this module
    'method',         # static: specified method from main:: 
  );

If you specify PATH/ name of module/classes will be taken from uri as path component and converted to Perl module name with substitution '::' for '/'. Example:

  urn:My/Examples              => My::Examples
  urn://localhost/My/Examples  => My::Examples
  http://localhost/My/Examples => My::Examples

For consistency first '/' in the path will be ignored.

According to this scheme to deploy new class you should put this class in one of the specified directories and enjoy its services. Easy, eh?

handle()

handle method will handle your request. You should provide parameters with request() method, call handle() and get it back with response() .

request()

request method gives you access to HTTP::Request object which you can provide for Server component to handle request.

response()

response method gives you access to HTTP::Response object which you can access to get results from Server component after request was handled.

PROXY SETTINGS

You can use any proxy setting you use with LWP::UserAgent modules:

 SOAP::Lite->proxy('http://endpoint.server/', 
                   proxy => ['http' => 'http://my.proxy.server']);

or

 $soap->transport->proxy('http' => 'http://my.proxy.server');

should specify proxy server for you. And if you use HTTP_proxy_user and HTTP_proxy_pass for proxy authorization SOAP::Lite should know how to handle it properly.

COOKIE-BASED AUTHENTICATION

  use HTTP::Cookies;

  my $cookies = HTTP::Cookies->new(ignore_discard => 1);
    # you may also add 'file' if you want to keep them between sessions

  my $soap = SOAP::Lite->proxy('http://localhost/');
  $soap->transport->cookie_jar($cookies);

Cookies will be taken from response and provided for request. You may always add another cookie (or extract what you need after response) with HTTP::Cookies interface.

You may also do it in one line:

  $soap->proxy('http://localhost/', 
               cookie_jar => HTTP::Cookies->new(ignore_discard => 1));

SSL CERTIFICATE AUTHENTICATION

To get certificate authentication working you need to specify three environment variables: HTTPS_CERT_FILE, HTTPS_KEY_FILE, and (optionally) HTTPS_CERT_PASS:

  $ENV{HTTPS_CERT_FILE} = 'client-cert.pem';
  $ENV{HTTPS_KEY_FILE}  = 'client-key.pem';

Crypt::SSLeay (which is used for https support) will take care about everything else. Other options (like CA peer verification) can be specified in a similar way. See Crypt::SSLeay documentation for more details.

Those who would like to use encrypted keys may check http://groups.yahoo.com/group/soaplite/message/729 for details.

COMPRESSION

SOAP::Lite provides you with the option for enabling compression on the wire (for HTTP transport only). Both server and client should support this capability, but this should be absolutely transparent to your application. The Server will respond with an encoded message only if the client can accept it (indicated by client sending an Accept-Encoding header with 'deflate' or '*' values) and client has fallback logic, so if server doesn't understand specified encoding (Content-Encoding: deflate) and returns proper error code (415 NOT ACCEPTABLE) client will repeat the same request without encoding and will store this server in a per-session cache, so all other requests will go there without encoding.

Having options on client and server side that let you specify threshold for compression you can safely enable this feature on both client and server side.

Client
  print SOAP::Lite
    -> uri('http://localhost/My/Parameters')
    -> proxy('http://localhost/', options => {compress_threshold => 10000})
    -> echo(1 x 10000)
    -> result
  ;
Server
  my $server = SOAP::Transport::HTTP::CGI
    -> dispatch_to('My::Parameters')
    -> options({compress_threshold => 10000})
    -> handle;

Compression will be enabled on the client side if the threshold is specified and the size of current message is bigger than the threshold and the module Compress::Zlib is available.

The Client will send the header 'Accept-Encoding' with value 'deflate' if the threshold is specified and the module Compress::Zlib is available.

Server will accept the compressed message if the module Compress::Zlib is available, and will respond with the compressed message only if the threshold is specified and the size of the current message is bigger than the threshold and the module Compress::Zlib is available and the header 'Accept-Encoding' is presented in the request.

EXAMPLES ^

Consider following examples of SOAP servers:

CGI:
  use SOAP::Transport::HTTP;

  SOAP::Transport::HTTP::CGI
    -> dispatch_to('/Your/Path/To/Deployed/Modules', 'Module::Name', 'Module::method') 
    -> handle
  ;
daemon:
  use SOAP::Transport::HTTP;

  my $daemon = SOAP::Transport::HTTP::Daemon
    -> new (LocalAddr => 'localhost', LocalPort => 80)
    -> dispatch_to('/Your/Path/To/Deployed/Modules', 'Module::Name', 'Module::method') 
  ;
  print "Contact to SOAP server at ", $daemon->url, "\n";
  $daemon->handle;
mod_perl:

httpd.conf:

  <Location /soap>
    SetHandler perl-script
    PerlHandler SOAP::Apache
  </Location>

Apache.pm:

  package SOAP::Apache;

  use SOAP::Transport::HTTP;

  my $server = SOAP::Transport::HTTP::Apache
    -> dispatch_to('/Your/Path/To/Deployed/Modules', 'Module::Name', 'Module::method'); 

  sub handler { $server->handler(@_) }

  1;
Apache::Registry:

httpd.conf:

  Alias /mod_perl/ "/Apache/mod_perl/"
  <Location /mod_perl>
    SetHandler perl-script
    PerlHandler Apache::Registry
    PerlSendHeader On
    Options +ExecCGI
  </Location>

soap.mod_cgi (put it in /Apache/mod_perl/ directory mentioned above)

  use SOAP::Transport::HTTP;

  SOAP::Transport::HTTP::CGI
    -> dispatch_to('/Your/Path/To/Deployed/Modules', 'Module::Name', 'Module::method') 
    -> handle
  ;

WARNING: dynamic deployment with Apache::Registry will fail, because module will be loaded dynamically only for the first time. After that it is already in the memory, that will bypass dynamic deployment and produces error about denied access. Specify both PATH/ and MODULE name in dispatch_to() and module will be loaded dynamically and then will work as under static deployment. See examples/server/soap.mod_cgi for example.

TROUBLESHOOTING ^

Dynamic libraries are not found

If you see in webserver's log file something like this:

Can't load '/usr/local/lib/perl5/site_perl/.../XML/Parser/Expat/Expat.so' for module XML::Parser::Expat: dynamic linker: /usr/local/bin/perl: libexpat.so.0 is NEEDED, but object does not exist at /usr/local/lib/perl5/.../DynaLoader.pm line 200.

and you are using Apache web server, try to put into your httpd.conf

 <IfModule mod_env.c>
     PassEnv LD_LIBRARY_PATH
 </IfModule>
Apache is crashing with segfaults (it may looks like "500 unexpected EOF before status line seen" on client side)

If using SOAP::Lite (or XML::Parser::Expat) in combination with mod_perl causes random segmentation faults in httpd processes try to configure Apache with:

 RULE_EXPAT=no

-- OR (for Apache 1.3.20 and later) --

 ./configure --disable-rule=EXPAT

See http://archive.covalent.net/modperl/2000/04/0185.xml for more details and lot of thanks to Robert Barta <rho@bigpond.net.au> for explaining this weird behavior.

If it doesn't help, you may also try -Uusemymalloc (or something like that) to get perl to use the system's own malloc. Thanks to Tim Bunce <Tim.Bunce@pobox.com>.

CGI scripts are not running under Microsoft Internet Information Server (IIS)

CGI scripts may not work under IIS unless scripts are .pl, not .cgi.

DEPENDENCIES ^

 Crypt::SSLeay             for HTTPS/SSL
 SOAP::Lite, URI           for SOAP::Transport::HTTP::Server
 LWP::UserAgent, URI       for SOAP::Transport::HTTP::Client
 HTTP::Daemon              for SOAP::Transport::HTTP::Daemon
 Apache, Apache::Constants for SOAP::Transport::HTTP::Apache

SEE ALSO ^

 See ::CGI, ::Daemon and ::Apache for implementation details.
 See examples/server/soap.cgi as SOAP::Transport::HTTP::CGI example.
 See examples/server/soap.daemon as SOAP::Transport::HTTP::Daemon example.
 See examples/My/Apache.pm as SOAP::Transport::HTTP::Apache example.

COPYRIGHT ^

Copyright (C) 2000-2001 Paul Kulchenko. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR ^

Paul Kulchenko (paulclinger@yahoo.com)

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