WSDL/SOAP/XML-RPC HELP

[Tomislav Lepusic]

Hello,

I don't know if this is the right group (I'm more in Perl, know nothing
about Python), so if you can help me thanks, if not, sorry to bother you.


I'm working on my student project and I'm totally lost and don't have
any idea how to continue, and the deadline is 1.9.2004. Please help,
'couse i'm loosing myself in this XML/SOAP/RPC/WSDL things......

A little discription.
I have to define and make something like virtual driver for serial port
(RS232), only it isn't really a driver. The server has to be on Linux
box (physical port(s) is/are there), and the other side (client) is not
inportant. It is not important what is connected on serial port. Also,
there is no need to work on any kind of drivers on Windows or something,
becouse that is not the point. I have to make an universal way to
send/recive/control serial port on that server computer from anywhere. I
know how to program for serial port on Linux (in C), and I have made
some progress there. That low-level programing isn't the problem. The
problem is how to make it work over the net, so that someone who wants
to write a program on Windows or Mac can use something universal to
access it (like XML). I HAVE TO USE XML-RPC or SOAP or WSDL or
something like that. The problem is that I don't know how to use those
technologies. I read some tutorials, guides on XML-RPC, SOAP and WSDL,
and I'm totally lost now.
BTW, I was planning to use Perl becouse I know something about it. (I
don't know Java)

So, if you can help me in any way (advice, similar example or
something), please do. This is very important to me. I forget,
everything must be secure (SSL or something).

Thank you

Tom

 

[Harry George]

Hello,

I don't know if this is the right group (I'm more in Perl, know
nothing about Python), so if you can help me thanks, if not, sorry to
bother you.


I'm working on my student project and I'm totally lost and don't have
any idea how to continue, and the deadline is 1.9.2004. Please help,
'couse i'm loosing myself in this XML/SOAP/RPC/WSDL things......

A little discription.
I have to define and make something like virtual driver for serial
port (RS232), only it isn't really a driver. The server has to be on
Linux box (physical port(s) is/are there), and the other side (client)
is not inportant. It is not important what is connected on serial
port. Also, there is no need to work on any kind of drivers on Windows
or something, becouse that is not the point. I have to make an
universal way to send/recive/control serial port on that server
computer from anywhere. I know how to program for serial port on Linux
(in C), and I have made some progress there. That low-level programing
isn't the problem. The problem is how to make it work over the net, so
that someone who wants to write a program on Windows or Mac can use
something universal to access it (like XML). I HAVE TO USE XML-RPC or
SOAP or WSDL or something like that. The problem is that I don't know
how to use those technologies. I read some tutorials, guides on
XML-RPC, SOAP and WSDL, and I'm totally lost now.
BTW, I was planning to use Perl becouse I know something about it. (I
don't know Java)

So, if you can help me in any way (advice, similar example or
something), please do. This is very important to me. I forget,
everything must be secure (SSL or something).

Thank you

Tom

1. Many of us spent time in perl-land, and feel the move to python is
worth your while, especially if you are currently confused. Python
is an excellent environment ofr learning new problem spaces, even if you
later implement in other languages.

2. To learn more about XML, there are zilions of books. I find
E.R. Harold's "XML Bible", IDG Books to be useful -- enough
examples to get going, but not so much detail you get lost. You
still have to visit the specs at:
http://xml.coverpages.org/xml.html
http://www.w3.org/TR/1998/REC-xml-19980210.html

You probably don't need to know this to use XMPRPC. Just follow
the examples. For SOAP, you probably do need a good sense of XML
and XSchemas.

3. To learn more about SOAP/WSDL, see James Snell et al "Programming
Web Services with SOAP", O'Reilly, 2002. There are enough examples
to get the feel for it. If you are working in python, see
http://pywebsvcs.sourceforge.net/

4. In the opinion of many sensible people, SOAP/WSDL is a monster that
started as an MS .COM extension of XMLRPC and got totally out of
control. Or more to the point, got out of the control of standards
efforts to "play well with others", and got into the control of
corporations seeking a new mechanism for proprietary lockin.

5. XMLRPC is the quick/cheap way to get web services. In Python it is
pretty straightforward. See
http://www.python.org/cgi-bin/moinmoin/XmlRpc

6. Assuming you are new to programming as well as XML/SOAP/WSDL, here
are some std approaches to learning new problem domains:

5.1. Do a literature search, get tutorials, ask for help -- you are
doing this.

5.2. Setup a small testbed to learn the mechanisms. Typically start
with a known good source or server, and read/parse/process that.
Then learn to write/generate/serve. In this case, you should
probably follow the XMPRPC example above. This is NOT your
actual classroom exercise -- it is just a learning environment.
Once you understand the mechanisms, you can architect and develop
your project. You can even grow them side-by-side (learn some
more, then code some more, etc.)

5.3. In a system with several interacting parts (sounds like your
exercise), the biggest problem is system integration. This can
be a nightmare if you've left it to the last phase. Instead, get
the whole thing connected with minimal functionality right from
the start. E.g., a simple query at one end gets to the other end
and is acknowledged. Build an automated regression test process
around this (ask when you get to this point in python). Then add
functionality feature by feature, testing as you go.

 

[Eelco Hoekema]

Harry George schreef:

Chapter 12 of Dive into Python is an excellent start if you need to write
a SOAP-client. See: http://diveintopython.org/soap_web_services/index.html

eelco