05-04-2012 06:32 PM
I have an issue with the LabviewHTTPclient.lvlib:addheader.vi. It succesfully adds a header, but it doesn't clear the header value when presented an empty string (as described in the help file). I use it for interfacing with a RESTful webservice which requires custom headers. Now I have to close and reopen the "connection" to get rid of the old header value. Furthermore, I cannot overwrite the header: it will postfix new values to the old value.
Solved! Go to Solution.
05-09-2012 09:31 AM
Hello,
Could you send met the whole project?
Kind regards,
Corné Westeneng
Applications Engineer
NI-Netherlands
07-10-2012 05:07 AM
Sorry Corne, I will not upload the code. Furthermore, you need a webservice or HTTP server to communicate with. I believe it is a bug in addheader.vi that should be resolved in the next releaase of Labview.
07-12-2012 07:16 AM
Hi,
Thanks for your response.
Is it possible for you to post the steps to reproduce the incorrect behaviour?
When I have this information I can make a CAR(corrective action request). We use CAR's to update our software.
Thanks inadvance.
Best regards,
Corné Westeneng
Applications Engineer
NI-Netherlands
07-13-2012 05:08 PM
Not really. I am making a user interface for the Mintouch deki webservice. It is a RESTful webservice that requires special http headers. In the image you can see you must set a header named ETag when updating a certain webservice property value. In the disabled box you see I have tried to empty the value by writing an empty string to it, which didn't work. I end up having to reset the connection to get rid of the existing ETag header value. If I don't create a new connection, the addheader.vi will just keep on concatenating old ETag values.
It has nothing much to do with my particular webservice or HTTP header name; You can try it on any http server.
07-17-2012 06:42 AM
Hi,
According to your information I found a CAR (corrective action request) for your problem.
So, our R&D is aware about this incorrect behaviour.
A possible workaround is: Create and destroy a client handle for each request.
Do you have enough information now?
Best regards,
Corné Westeneng
Application Engineer
NI-Netherlands
07-17-2012 04:02 PM
Great. That's all I wanted. The new release is pending, too.