NAME Pod::WSDL2 - Creates WSDL documents from (extended) pod

This is a fork of Pod::WSDL by Tarek Ahmed, which appears
to be unmaintained.  The original Pod::WSDL covered about 
80-90% of what my colleagues and I (Maverick) needed it to do.
I suspect the same is probably true for others.  If Tarek
becomes active again, I'll happily merge my changes back
into the original; it's not my intent to make some of
"hostile take over", just to contribute back and not let
a excellent module rot away.

Where appropriate I've modified and extended the original
documentation.

INSTALLATION

To install this module type the following:

perl Makefile.PL make make test make install

SYNOPSIS use Pod::WSDL2;

  my $pod = new Pod::WSDL2(source => 'My::Server', 
    location => 'http://localhost/My/Server',
    pretty => 1,
    withDocumentation => 1);

  print $pod->WSDL;

DESCRIPTION - How to use Pod::WSDL2 Parsing the pod How does Pod::WSDL2 work? If you instantiate a Pod::WSDL2 object with the name of the module (or the path of the file, or an open filehandle) providing the web service like this

  my $pwsdl = new Pod::WSDL2(source => 'My::Module', 
        location => 'http://my.services.location/on/the/web');

Pod::WSDL2 will try to find "My::Module" in @INC, open the file, parse it
for WSDL directives and prepare the information for WSDL output. By
calling

  $pwsdl->WSDL;

Pod::WSDL2 will output the WSDL document. That's it.

When using Pod::WSDL2, the parser expects you to do the following:

* Put the pod directly above the subroutines which the web service's
  client is going to call. There may be whitespace between the pod and
  the sub declaration but nothing else.

* Use the "=begin"/"=end" respectively the "=for" directives according
  to standard pod: anything between "=begin WSDL" and "=end" will be
  treated as pod. Anything composing a paragraph together with "=for
  WSDL" will be treated as pod.

Any subroutine not proceeded by WSDL pod will be left unmentioned. Any
standard pod will be ignored (though, for an exception to this, see the
section on own complex types below).

The individual instructions for Pod::WSDL2 always begin with a keyword,
like "_RETURN" or "_DOC" or "_FAULT". After this different things may
follow, according to the specific type of instruction. The instruction
may take one or more lines - everything up to the next line beginning
with a keyword or the end of the pod is belonging to the current
instruction.

Describing Methods How do we use Pod::WSDL2? In describing a web service's method we have to say something about parameters, return values and faults. In addition you might want to add some documentation to these items and to the method itself.

Parameters WSDL differentiates between in-, out- and inout-parameters, so we do that, too. A different matter is the question, if the client can do this too, but now we are talking about possibilities, not actualities.

The pod string describing a parameter has the structure

  (_IN|_OUT|_INOUT) NAME ($|@)TYPE DESCRIPTION

like

  _IN foo $string This is a foo

or

  _INOUT bar @bar An array of bars

You will easily guess what "_IN", "_OUT" and "_INOUT" stand for so we
can move on. "NAME" is the name of your parameter. It does not have any
real function (the order of the parameters being the only important
thing) but it is nice to have it since in a WSDL document the parameters
need to have names. So instead of having Pod::WSDL2 automatically
generate cryptic names (it cannot do that right now) be nice to the
client and use some sensible name. The "TYPE" of the parameters can be
any of the xsd (schema) standard types (see [5]) or a type of your own
creation. The "$" resp. "@" symbols tell Pod::WSDL2 and your client if it
is a scalar or array parameter. Everything following the type up to the
next instruction is treated as the parameter's documentation. If you
call the constructor of Pod::WSDL2 with the argument "withDocumentation
=> 1", it will be added to the WSDL.

Return Values Return values work like parameters but since in WSDL there is provision for only one return value (you have (in)out parameters, or can return arrays if that isn't enough), you do not need to give them a name. Pod::WSDL2 will automatically call them 'Return' in the WSDL document. So, the structure of "_RETURN" instructions is

  _RETURN ($|@)TYPE DESCRIPTION

as in

  _RETURN $string Returns a string

The pod for one method may only have one "_RETURN" instruction. If you
don't specify a "_RETURN" instruction, Pod::WSDL2 will assume that you
return void. Of course the perl subroutine still will return something,
but your web service won't. To make this clear Pod::WSDL2 generates an
empty response message for this.

If you want some method to be a one way operation (see [4], ch. 2.4.1),
say so by using the instruction "_ONEWAY" in the pod. In this case no
response message will be generated and a "_RETURN" instruction will be
ignored.

Faults SOAP faults are usually translated into exceptions in languages like Java. If you set up a web service using SOAP::Lite, SOAP will trap your dying program and generate a generic fault using the message of "die". It is also possible to access SOAP::Lite's SOAP::Fault directly if you want more control - but this is not our issue. If you want to use custom-made fault messages of your own, define them in "_FAULT" instructions, which look like this:

  _FAULT TYPE DESCRIPTION

An example could be the following:

  _FAULT My::Fault If anything goes wrong

Since you probably won't return an array of fault objects, you do not
need to use the "($|@)" tokens. Just say that you return a fault,
declare it's type and add an optional description.

As with parameters (but in contrary to "_RETURN" instructions) you can
declare as many "_FAULT" instructions as you like, providing for
different exception types your method might throw.

Method Documentation Method documentation is easily explained. It's structure is

  _DOC Here comes my documentation ...

That's it. Use several lines of documentation if you like. If you
instantiate the Pod::WSDL2 object with the parameter "withDocumentation
=> 1", it will be written into the WSDL document.

Describing Modules - Using Own Complex Types Quite often it will be the case that you have to use complex types as parameters or return values. One example of this we saw when talking about faults: you might want to create custom fault types (exceptions) of your own to fulfill special needs in the communication between web service and client. But of course you also might simply want to pass a complex parameter like a address object containing customer data to your application. WSDL provides the means to describe complex types borrowing the xsd schema syntax. Pod::WSDL2 makes use of this by allowing you to add WSDL pod to your own types. Assuming you have some own type like

  package My::Type;

  sub new {
    bless {
      foo => 'foo',
      bar => -1
    }, $_[0];
  }

  1;

simply describe the keys of your blessed hash like this.

  =begin WSDL

    _ATTR foo $string A foo
    _ATTR bar $integer And a bar

  =end WSDL

Put this pod anywhere within the package My::Type. Pod::WSDL2 will find
it (if it is in @INC), parse it and integrate it into the WSDL document.
The "_ATTR" instruction works exactly as the "_IN", "_OUT" and "_INOUT"
instructions for methods (see above).

If you initialize the Pod::WSDL2 object using "withDocumentation => 1",
Pod::WSDL2 will look for standard pod in the module, parse it using
Pod::Text and put it into the WSDL document.

METHODS new Instantiates a new Pod::WSDL2.

Parameters

• source - Name of the source file, package of the source module or file handle on source file for which the WSDL shall be generated. This source must contain specialized Pod tags. So, if your source is '/some/directory/modules/Foo/Bar.pm' with package declaration 'Foo::Bar', source may be '/some/directory/modules/Foo/Bar.pm' or 'Foo::Bar' (in which case '/some/directory/modules' has to be in @INC) or an open file handle on the file. Right?

• location - Target namespace for the WSDL, usually the full URL of your webservice's proxy.

• pretty - Pretty print WSDL, if true. Otherwise the WSDL will come out in one line. The software generating the client stubs might not mind, but a person reading the WSDL will!

• withDocumentation - If true, put available documentation in the WSDL (see "Pod Syntax" above). For used own complex types ('modules') this will be the output of Pod::Text on these modules. The software generating the client stubs might give a damn, but a person reading the WSDL won't!

  WSDL Returns WSDL as string.

  Parameters

• pretty - Pretty print WSDL, if true. Otherwise the WSDL will come out in one line. The software generating the client stubs might not mind, but a person reading the WSDL will!

• withDocumentation - If true, put available documentation in the WSDL (see "Pod Syntax" above). For used own complex types ('modules') this will be the output of Pod::Text on these modules. The software generating the client stubs might give a damn, but a person reading the WSDL won't!

  addNamespace Adds a namespace. Will be taken up in WSDL's definitions element.

  Parameters 1 URI of the namespace

  2 Declarator of the namespace

EXTERNAL DEPENDENCIES Carp XML::Writer IO::Scalar Pod::Text

The test scripts use

  XML::XPath

EXAMPLES see the *.t files in the distribution

BUGS Please send me any bug reports, I will fix them or mention the bugs here :-)

TODO Describe Several Signatures for one Method Of course, one subroutine declaration might take a lot of different sets of parameters. In Java or C++ you would have to have several methods with different signatures. In perl you fix this within the method. So why not put several WSDL pod blocks above the method so the web service's client can handle that.

Implement a Better Parsing of the pod Right know, the pod is found using some rather complex regular expressions. This is evil and will certainly fail in some situations. So, an issue on top of the fixme list is to switch to regular parsing. I'm not sure if I can use Pod::Parser since I need the sub declaration outside the pod, too.

Handle Several Package Declarations in One File So far, Pod::WSDL2 assumes a one to one relation between packages and files. If it meets several package declarations in one file, it will fail some way or the other. For most uses, one package in one file will presumably suffice, but it would be nice to be able to handle the other cases, too.

Handle Array based blessed References Array based blessed references used for complex types are something of a problem.

Get Information on Complex Types from Somewhere Else If you use complex types for parameters that are not your own (we assume, that the module containing the web service always is your own), you might not be able to put the WSDL pod into the module files. So why not fetch it from somewhere else like a configuration file?

Integrate Pod::WSDL2 with SOAP::Lite With Axis, you simply call the web service's URL with the parameter '?wsdl' and you get the WSDL document. It would be nice to be able to do this with SOAP::Lite, too.

Implement Non RPC Style Messages Pod::WSDL2 writes WSDL documents in encoded RPC style. It should be able to generate literal RPC and document styles, too.

REFERENCES [1] http://ws.apache.org/axis/

[2] <http://search.cpan.org/~kbrown/SOAP-0.28/>

[3] <http://search.cpan.org/~byrne/SOAP-Lite-0.65_5/>

[4] <http://www.w3.org/TR/wsdl.html>

[5] <http://www.w3.org/TR/xmlschema-2/>

SEE ALSO http://ws.apache.org/axis/ http://search.cpan.org/~kbrown/SOAP-0.28/ http://search.cpan.org/~byrne/SOAP-Lite-0.65_5/ http://www.w3.org/TR/wsdl

  WSDL::Generator (a different way to do it)
  SOAP::WSDL (the client side)
  SOAP::Clean::WSDL (I have not tried this)

AUTHOR Tarek Ahmed, <bloerch -the character every email address contains- oelbsk.org>

COPYRIGHT AND LICENSE Copyright (C) 2006 by Tarek Ahmed

This library is alpha software and comes with no warranty whatsoever. It
is free software; you can redistribute it and/or modify it under the
same terms as Perl itself, either Perl version 5.8.5 or, at your option,
any later version of Perl 5 you may have available.