Few questions on SOAP

[Mark Lawrence]

Muhammad Alkarouri wrote:
> Your question is borderline if not out of topic in this group. I will
> make a few comments though.
This might be a Python group, but threads often drift way off topic, 
which added to the language itself make this a great group to read.  If 
you don't like the way a thread goes, you can always skip it.
> 
> On Feb 18, 3:36 pm, joy99 <subhakolkata1... at gmail.com> wrote:
>> Dear Group,
>>
>> I was reading on SOA or Service Oriented Architecture for last few
>> days and got some questions. As this is a room for the expert computer
>> scientists, if you can help me solve my queries.
>>
>> As per I read and felt SOA is an architecture, which relies on few
>> basic principles as,
>> the system must be modular, the modules must be distributive, module
>> interfaces must be clearly defined and documented, module that
>> implements a service can be swapped out for another module that offers
>> the same service and interface, service provider modules must be
>> shareable.
>> SOA is an architecture which is now a days governed like XML by W3C.
> 
> SOA is an architecture which can be implemented using any of a number
> of different middleware choices. It is not governed or controlled by
> anyone. You are mixing it up with SOAP, which is a web services
> technology, currently governed by W3C.
> For example, I tend to use SOA implemented using REST
> (Representational State Transfer).
> 
> All of these technologies are somewhat explained in wikipedia. You
> probably want to start there.
> 
>> The latest version is SOAP 1.2.
> 
> This is the latest of SOAP, not SOA.
> 
>> SOA is implemented mainly in a client/server environment, where
>> applications have the use of service, thus we can say it is a service-
>> oriented architecture.
>> It is a step towards cloud computing with its sister WSDL and BPM.
> 
> A SOAP web service is described using WSDL. BPM is not really
> connected with them, but is probably more connected with SOA as an
> architecture. BPM can be implemented using SOAP/WSDL web services, as
> can SOA.
> 
>> If both client/server are following the SOA then they can communicate
>> and exchange information without worrying for platform.
> 
> You mean SOAP here.
> In real life, there are interoperability issues. So various
> implementations of SOAP will need a bit of work to actually work
> together.
> 
> SOA is an architecture and does not help exchanging information in a
> direct way.
> 
>> SOAP is a software implementation of Python,.NET,J2EE based on this
>> principle.
> 
> SOAP is a web services protocol that was created before the concept of
> SOA was developed enough for use and is largely independent of it.
> SOAP has been implemented in many different languages, like
> Java, .Net, C/C++, Python, etc.
> 
>> SOAPPy is a Python implementation.
> 
> SOAP implementations in Python are not of the best quality (in my
> opinion, there are better ways to achieve the ends needed). SOAPpy is
> currently a bit out of date. The better ones are ZSI (for client and
> server) and suds (for clients).
> 
> I guess I have already answered some of your questions.
> 
>> My questions are:
>> (i)     Am I understanding correctly?
> 
> See above.
> 
>> (ii)    Does SOAP has any standard architecture like UML other than the
>> W3C one?
> 
> Depends on what you mean by architecture. SOAP is a standard. UML is a
> way of modelling software and can be used to model web services, which
> can then be implemented in SOAP.
> 
>> (iii)   Can I write short programs to check the SOAP using my personal
>> computer as client as well as Server?
> 
> Yes. Try ZSI examples (http://pywebsvcs.sourceforge.net/zsi.html).
> 
>> (iv)    Is SOAPpy fine?
> 
> See above.
> 
>> (v)     What is the difference among SOAP, WSDL and BPM.
> 
> SOAP standardise the communication between client and server. WSDL
> describes the methods provided by a server to be consumed by a client
> (interfaces in Java language). BPM is a management method to improve
> business and is not a software protocol but an approach.
> 
>> (vi)    As SOAP is for communication with a server if I pick a URL and
>> start to communicate with Google/Yahoo would they allow?
> 
> To be able to talk SOAP to a server, it must understand SOAP. Some of
> those companies do provide SOAP web service access, but their standard
> search pages are accessible in pure HTTP (the way you browser uses
> them).
> To access a SOAP service you need to know the functions exported by
> it, which are usually defined in a WSDL document.
> 
>> (vii)   Can I design a web based robot/crawler with SOAP?
> 
> No. Web pages are accessed using simple HTTP. SOAP is usually deployed
> on top of HTTP, but most web pages are not communicated using SOAP.
> You can search for Python web crawling; there are a lot of examples on
> the web.
> 
> 
> Regards,
> 
> k