Web Dynpro ABAP Stylesheet - Portal Integration

Question

We have a Web Dynpro ABAP being displayed through a Portal iView.  The Portal server and the Web Dynpro ABAP server are separate.  Our problem is in getting the Web Dynpro ABAP to use the stylesheet of the Portal.
We can make this work by forcing an external stylesheet (via application parameters, global Dynpro settings, or passed on the end of the URL), but we have to hard-code the full URI of the Portal stylesheet.  This would be very hard to manage if we hard-code every iView's CSS location (or set every individual Web Dynpro's application parameters), and we want instead for the Portal to supply whatever the user's stylesheet is dynamically. 
So what we want is: if we change the Portal stylesheet, the Portal would just pass the new stylesheet URI to our ABAP Web Dynpro iViews without manual modification of the iViews.
Here is an example of what works:
http://our-abap-server.com/sap/bc/webdynpro/sap/cprojects?sap-ep-themeroot=https://our-portal-server.com/irj/portalapps/com.sap.portal.design.portaldesigndata/themes/portal/ourportalstylesheetname
Shouldn't the Portal iView automatically pass sap-cssurl or sap-ep-themeroot to Web Dynpro ABAP?  We have "Supply Portal Stylesheet" checked on the iView… it just doesn't pass anything to the Web Dynpro ABAP.  Why wouldn't SAP pass this parameter dynamically to the Web Dynpro ABAPs?  Is this a product error? 
There seems to be a great deal of confusion about this on the SDN message forums... I think this may be the core issue.
We are using a 7.0 SP13 Portal with an ECC 6.0 SP12 backend.

Answer 1

Now that you mention it, I ran into that exact same issue  -- the application parameters didn't work for hard-coding the theme.  The fix ended up being the web server semicolon thing I mentioned earlier (that was why the parameter didn't make it to the backend). 
The themeroot is automatically sent to the backend from the portal, so you shouldn't really have to manually send it as a parameter anyways.
I'd suggest talking to your network guys.  Also this could be the result of the SP you are on (we're on 13 for the portal and the backend system -- maybe this feature doesn't work in some earlier SP's?).  There are also some options to force the theme as a WD application parameter on the backend side, which you could check into.  Details on those are here:
[http://help.sap.com/saphelp_nw2004s/helpdata/en/7b/fb57412df8091de10000000a155106/frameset.htm]
Also you could look at the requests being made by installing HttpAnalyzer in your browser.  You can inspect "post" parameters going from the portal to the backend system.  One of those posts (the first one to the backend system) should contain the parameter sap-cssurl (same kind of thing as sp-ep-themeroot).  This is where our problem turned up as this parameter was not being posted.
Lastly, make sure that your frontend portal and backend portal are in the same domain.  For instance:
frontend.domain.com
backend.domain.com
If your backend and frontend are in different domains it messes all kinds of things up, including stylesheets I think.  If you can't get around this, then read about domain relaxing (but I highly recommend getting the domains the same).
When we started, ours were:
portal.dx.company.com
sap.company.com
This created all kinds of problems.  Putting our systems in the same domain with the same protocol and fixing our little semicolon web server problem fixed basically all of our portal complaints.  Up until that time, we had also had many problems with session management (backend sessions were getting stuck until the HTTP timeout).
That's all I know.   Good luck.