Re: SOAPpy and callback
Ok guys, thanks for the lesson! I'm probably not going to try to implement this solution. However, I've learned a lot! -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
Diez B. Roggisch [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Maybe we have a misunderstanding here. I'm not a native speaker, so bear with me. That's okay, I'll type very, very slowly. :) In CORBA or RMI, there is a notion of an object/interface reference passed around, which allows for callbacks in a natural way. Which is AFAIK not the case in SOAP. Hell, they don't even know objects and stateful connections... Are you confusing SOAP with REST? The standard I refer to defines a set of WSDL files that can be crunched to build implementation bindings for C#, Boo, Java, etc. (Unfortunately, not Python - there is some issue with SOAPpy that will not handle the input WSDL.) These bindings do model the remote interface bindings as objects, and stateful connections and sessions are very much part of the standard. If you like, you can download the WSDL files at http://dom.semi.org/web/wstandards.nsf/supmaterials. It is true, the implementation of the callback in SOAP is quite crude, as it exposes the callback as an endpoint wrapped around a URL string. Not very object-y at all - but then think back to CORBA again, and many systems did something similar by passing around names bound to objects in a nameserver, or just cut to the chase and shipped IOR's around directly. That you obviously can define a system that needs several SOAP servers to interact with each other - well, you could also perform inter process communication using printed documents, some horses and either OCR or data typists. But this isn't exactly inter process communication in my book, albeit there certainly _are_ processes, _and_ communication :) About 10 years ago, the standards body for semiconductor process integration *was* using IDL to define process interfaces, and defining CORBA implementation bindings. Unfortunately, the CORBA learning curve was too much, and the implementations were too expensive (at the time; today ACE and omniOrb are reasonable platforms). The group today went with SOAP, defining a set of WSDL files to serve as the standard interface definition, in place of the CORBA IDL of yore. And what you describe might still be a step up from the RS-232-based system in place today (instituted in the 70's, upgraded to ethernet in the late 80's, but still limited to encoded ASCII and point-to-point connections). I would definitely agree that working with callbacks in SOAP sometimes feels like an unnatural act. But it is clearly an interprocess communication, and it does have an object model to its language bindings. Any Rube Goldberg aspects to SOAP are neatly buried in the code generated from the WSDL. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
[EMAIL PROTECTED] schrieb: Hello, I'm trying to find how to use a callback in a SOAP client using SOAPpy. Does SOAPpy have to manage it, or does Python include some API to do it? I've never seen any callback mentioned in SOAP. Are you sure this is possible with any SOAP implementation, at least standard-wise? Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
SOAP standard doesn't provide any callback, and it looks like SOAPpy doesn't too. I remember using callbacks with Javascript and SOAP in Web pages. I was just wondering if there could be the same with Python. Thanks for your answer. -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
[EMAIL PROTECTED] schrieb: SOAP standard doesn't provide any callback, and it looks like SOAPpy doesn't too. I remember using callbacks with Javascript and SOAP in Web pages. I was just wondering if there could be the same with Python. How that? I seriously doubt that, it would mean that the server would be able to issue an request on its own to the browser - a technical impossibility in current browser implementations. Just because you used a callback inside a js-soap-implementation that works with deferreds or something similar doesn't mean that the soap itself knew callbacks. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
Diez B. Roggisch [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [EMAIL PROTECTED] schrieb: Hello, I'm trying to find how to use a callback in a SOAP client using SOAPpy. Does SOAPpy have to manage it, or does Python include some API to do it? I've never seen any callback mentioned in SOAP. Are you sure this is possible with any SOAP implementation, at least standard-wise? Diez This is most definitely possible, in fact it is the basis for a new asynchronous data collection standard for semiconductor equipment, Interface A (replacing the ancient SECS/GEM interface, originally designed to work over RS-232). However, it is a major pain to implement. As you suggest, you cannot do this from a simple browser or pure SOAP client. To support SOAP callbacks, the client must also itself be a SOAP server. The client sends its own callback server's URL to the primary server, and when callbacks are needed, they are sent to that callback URL. This really does get quite tricky, though. For one thing, the vagaries of network identification make it unsure whether the URL composed by the client for its callback is meaningful/accessible to the server. In addition, if you are considering implementing this over the untrusted internet, you should use SSL authentication both ways (although this further complicates your client). -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
Paul McGuire schrieb: Diez B. Roggisch [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [EMAIL PROTECTED] schrieb: Hello, I'm trying to find how to use a callback in a SOAP client using SOAPpy. Does SOAPpy have to manage it, or does Python include some API to do it? I've never seen any callback mentioned in SOAP. Are you sure this is possible with any SOAP implementation, at least standard-wise? This is most definitely possible, in fact it is the basis for a new asynchronous data collection standard for semiconductor equipment, Interface A (replacing the ancient SECS/GEM interface, originally designed to work over RS-232). However, it is a major pain to implement. I don't call 'you can do that on your own' as standard-wise. Certainly you can run two servers, make sure they are mutually reachable, and client and server share the same process space. But that is not a callback - it is, as you say, a PITA. And a massive lack in the SOAP standard. Regards, Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
Diez B. Roggisch [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Paul McGuire schrieb: Diez B. Roggisch [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [EMAIL PROTECTED] schrieb: Hello, I'm trying to find how to use a callback in a SOAP client using SOAPpy. Does SOAPpy have to manage it, or does Python include some API to do it? I've never seen any callback mentioned in SOAP. Are you sure this is possible with any SOAP implementation, at least standard-wise? This is most definitely possible, in fact it is the basis for a new asynchronous data collection standard for semiconductor equipment, Interface A (replacing the ancient SECS/GEM interface, originally designed to work over RS-232). However, it is a major pain to implement. I don't call 'you can do that on your own' as standard-wise. Certainly you can run two servers, make sure they are mutually reachable, and client and server share the same process space. But that is not a callback - it is, as you say, a PITA. And a massive lack in the SOAP standard. Regards, Diez I like your term standard-wise. Although there is nothing in the SOAP standard that prevents this architecture, it is probably open for discussion whether it is wise. As it happens, the client and server *don't* share the same process space - they don't even share the same computer. And it *does* work, I'm running the software on a couple of systems in my office right now. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: SOAPpy and callback
I like your term standard-wise. Although there is nothing in the SOAP standard that prevents this architecture, it is probably open for discussion whether it is wise. Might stem from standardweise, the german word for something that is part of a standard, or e.g. something always having this or that feature. As it happens, the client and server *don't* share the same process space - they don't even share the same computer. And it *does* work, I'm running the software on a couple of systems in my office right now. Maybe we have a misunderstanding here. I'm not a native speaker, so bear with me. In CORBA or RMI, there is a notion of an object/interface reference passed around, which allows for callbacks in a natural way. Which is AFAIK not the case in SOAP. Hell, they don't even know objects and stateful connections... That you obviously can define a system that needs several SOAP servers to interact with each other - well, you could also perform inter process communication using printed documents, some horses and either OCR or data typists. But this isn't exactly inter process communication in my book, albeit there certainly _are_ processes, _and_ communication :) Diez -- http://mail.python.org/mailman/listinfo/python-list
SOAPpy and callback
Hello, I'm trying to find how to use a callback in a SOAP client using SOAPpy. Does SOAPpy have to manage it, or does Python include some API to do it? Thanks a lot. Fabien -- http://mail.python.org/mailman/listinfo/python-list
