[Gvsig_english] WMS connection header

jaume dominguez faus jaume.dominguez at iver.es
Tue Jul 17 14:15:25 CEST 2007


En/na rndbrb at libero.it ha escrit:

>ok Jaume
>Sorry for the errors in the previuos post and lets start from the beginning.
>To understand the follwing cons keep in mind that:
>
>A) HTTP is a stateless protocol;
>B) Access to a WMS URL via GVSIg client is somewhat different then doing the same in a web browser (communication and, above all, the response has much more constraints).
>C) the URL contained in the text below are only dummy url.
>
>Suppose you have a WMS server (in previous post sometimes you found WFS instead of WMS, I was wrong, i meant the server exposes WMS service and the client shows WMS data) exposing a single .shp file land_cover(ID, type, surface) and say you have two kind of clients (two offices) accessing the server. 
>The first office  has to process a subset of the attributes in the shape while the second migth be interested in others.
>This might be the case, for example, when an office works on quanatitative aspects, like percent of land covered by trees (for 
>this clients only 'surface' should be the output), and the other office works on the dynamics of the types on the land (the 
>client in this case should show only the attribute 'type' of the shape).
>The same WMS service (the same URL) should produce two different responses for personnel belonging to the two offices. 
>Another case where you might request a different response depending on the office (i.e the client ) is when the two offices 
>competences differ by geographic area. So when a clerk belonging to the office 'A' requests the url "http://www.myWms/" he doesn't have to worry about selecting the area he works on, the WMS server can do the job for him. 
>Still another case might be when you simply want to protect your spatial data and make it accessible only for some web users.
>The goal till now is: one service, and hence one set of geographic data,  many ways of using it (am I asking too much ??)
>How can we make it possible via http ??
>  
>
Isn't it simpler if you just create a .map file for each service in the 
same MapServer machine and grant access (via Apache's .htaccess or so) 
to one or another and then each .map file gives the behavior that you 
are looking for? The process is the same (the URL says which service 
will you be able to see by pointing to one .map file or to other) and 
you don't need to care about to produce your own authentication code.

More over, authentication is not defined in WMS so I'd bid for this 
solution rather than the script. It is a lot simpler (if I understood 
well the problem).

Was I useful?
Regards,

-- 
Jaume Dominguez Faus


Àrea de Software Lliure
Equip gvSIG
Iver TI
C. Salamanca, 52
46005 València
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