[Ctk-developers] CTK based Hosted App fails when launched from Non-CTK Host

[Benoit Bleuze]

Hi Anthony, Sascha gave you all the technical answers we had in stock so far, but I can add a bit of context here, it may help. As Sascha said, the state/newState switch is due to XIP not following the specifications. And your change is valid. We started with "state", but the only other host we could use being XIP, we changed it. You are welcome to revert it. I think we notified Larry (Lawrence Tarbox) of that problem during the last hackfest in Chapel Hill. Eventually XIP will change its API there (or so I hope). Replacing the WSDL files doesn't change anything since we don't use them to generate the interface, all the messages are hard coded soap messages constructed from C++. Now I know nothing of the WCF unfortunately, so I can't tell you whether the "type:" keyword is misinterpreted or whatever. Sascha's suggestion of changing the casing sounds promising to me. I remember we used capitals in some actions , following the WSDL actually, and had to change it afterwards for specifications and XIP compatibility. I remember Larry telling us the WSDL provided in the specs was not up to date, and thus we provide an updated (or at least it was valid last february) set of WSDL (and siblings) files there: http://www.commontk.org/index.php/File:Wsdl_ft.zip Note that they also have actions starting with capitals. I have a faint memory of Larry giving us an explanation as to why they were upper cased, but I can't remember the reason, my guess is that the .Net implementation forced them to do so. And it is very well possible that the XIP java implementation accepts both casing and the .NET or WCF are stricter, so I guess you'll have to choose between the proposed WSDL and the specifications... Keep us posted of your progress. Ben ----- Original Message -----
> Hi Anthony,
> Welcome to the ctk-developers list.
> > We've tried adapting one of our DICOM application into a CTK Based
> > Hosted App. It works well when tried with the ctkhost - we could
> > launch the app, load the DICOM data and get through different states
> > as well.
> So far, good news.
> > However when tried launching the same app with different non-ctk
> > based
> > host, it launches our app but fails to load any data. This non-ctk
> > based host seems to be written using the WCF as per specification in
> > DICOM 118.
> Please note that we could only test our implementation against the XIP
> host (written in Java) so far. So the problems you are experiencing
> might very well relate to our implementation.
> > On investigating, we noticed that the initial ‘IDLE’ message sent by
> > the App upon launch is not getting processed by the Non-CTK based
> > host.
> > When traced the SOAP communication, we found out that the messages
> > from the plug-in are getting to the host, but then they are not
> > processed by WCF because of some WSDL contacts mismatch. Thus the
> > host
> > does not receive any messages. Here’s the log message:
> > < Message > The message with Action '' cannot be processed at the
> > receiver, due to a ContractFilter mismatch at the
> > EndpointDispatcher.
> > This may be because of either a contract mismatch (mismatched
> > Actions
> > between sender and receiver) or a binding/security mismatch between
> > the sender and the receiver. Check that sender and receiver have the
> > same contract and the same binding (including security requirements,
> > e.g. Message, Transport, None). </ Message >
> > When debugging the WCF processing of the message we get the
> > deserialization error:
> > "The ':' character, hexadecimal value 0x3A, cannot be included in a
> > name. Line 4, position 11."
> > Here’s the SOAP message braced between the CTK-plugin and Non-CTK
> > based Host:
> > < SOAP-ENV:Envelope xmlns:SOAP-ENV = "
> > http://schemas.xmlsoap.org/soap/envelope/ " SOAP-ENV:encodingStyle =
> > "
> > http://schemas.xmlsoap.org/soap/encoding/ " xmlns:xsd = "
> > http://www.w3.org/1999/XMLSchema " >
> > < SOAP-ENV:Body xmlns:SOAP-ENV = "
> > http://schemas.xmlsoap.org/soap/envelope/ " >
> > < notifyStateChanged xmlns = " http://wg23.dicom.nema.org/ " >
> > < newState :type = " xsd:string " > IDLE </ newState >
> > </ notifyStateChanged >
> > </ SOAP-ENV:Body >
> > </ SOAP-ENV:Envelope >
> > We can see the “:type” item in the newState element that’s causing
> > the
> > error in WCF. Also, per DICOM supplement 118 it should be called
> > “state”, not “newState”.
> Looking at the debug output from the CTK hosted app, the xml namespace
> for the "type" attribute in the "newState" tag is intact. So I am
> wondering it the output above has already been modified somehow by the
> WCF host or if it is the original message from the CTK hosted app.
> > Here’s the example of the SOAP message generated by Non-CTK based
> > HostedApp: < s:Envelope xmlns:s = "
> > http://schemas.xmlsoap.org/soap/envelope/ " > < s:Body > <
> > NotifyStateChanged xmlns = "
> > http://dicom.nema.org/PS3.19/HostService-20100825 " > < state > IDLE
> > </ state > </ NotifyStateChanged > </ s:Body > </ s:Envelope >
> > Next, we tried changing “newState” to “state” but again it fails
> > when
> > tried with the non-ctk based host and producing the same error.
> I think it is still either related to the ":type" attribute or the
> error described below. Concerning state/newState, please also see my
> comments below.
> > ...
> > 2011-09-06 17:17:59,609 <faultstring xsi:type="xsd:string"
> > xmlns:xsi="
> > http://www.w3.org/1999/XMLSchema-instance ">The message with Action
> > ''
> > cannot be processed at the receiver, due to a ContractFilter
> > mismatch
> > at the EndpointDispatcher. This may be because of either a contract
> > mismatch (mismatched Actions between sender and receiver) or a
> > binding/security mismatch between the sender and the receiver. Check
> > that sender and receiver have the same contract and the same binding
> > (including security requirements, e.g. Message, Transport,
> > None).</faultstring> ...
> This actually hints at a problem concerning the action names. Looking
> at the WSDL, the operation names start with upper case latters, where
> we are using lower case (unfortunately, the text in the DICOM Part 19
> specs refer to the method names with starting lower case letters).
> > I even tried replacing the WSDL files with the one provided by
> > Non-CTK
> > based host, but still it doesn’t seem to work.
> Yes, that does not change the actual behavior.
> > When looked at the code, I noticed a comment in the CTK code (below
> > methods) “spec would be "state", java has "newState" FIX
> > JAVA/STANDARD”. Could this be something we need to look for? If so
> > may
> > I know what would be the change in Java side.
> Unfortunately, again, the text in the specs refer to "newState" for
> the argument name and this is what the XIP host is using. So we used
> it too for testing with XIP. But I agree that the WSDL should be the
> definite guide and we should use "state" when not testing with XIP.
> My advice would be to keep your modification ("newState" -> "state")
> and also try to modify the action (method) names in
> ctkDicomAppService.cpp (lines 40 - 60) to use upper case for the first
> letter.
> I would be happy if you could keep us posted about your progress.
> Thanks,
> Sascha
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