SRS handling questions

[Jan-Oliver Wagner]

On Sun, Mar 21, 2004 at 07:44:01PM +0100, Martin Schulze wrote:
> I wonder how I should interpret the WMS specification with regards to
> SRS handling.
> 
> The specification [OGC 01-068r3, §7.1.4.5.5, page 26] says about
> inheritance of SRS:
> 
>  - Every layer shall have at least one SRS element that is either
>    stated explicitly or inherited from a parent layer.
> 
>  - Layers may optionally add to the global SRS list, or to the list
>    inherited from a parent layer.
> 
> Since the specs don't lose a word how these two cases are
> distinguished, I'd consider them clashing.

I do understand the first rule and the syntax should be clear.
To understand the second rule I would like to see an example to
understand how this rule is to be expressed in the syntax.

> Does anybody feel I should not implement the first rule and skip the
> latter?

Are you talking about the 2 rules or the 2 cases of the second rule?

> Also, since the XML response has both <SRS>foo</SRS> and
> <BoundingBox SRS="foo" minx=...> elements, I wonder if it wouldn't be
> wiser to extract information about availibl SRS from the <BoundingBox>
> element, except for the root layer.
> I'd say yes, but I'd better ask if somebody sees a problem with this.

Are you talking about XML responses that came from the frida demo wms?
If yes, please note that it is an older UMN MapServer and not
necessarily 100% compliant with WMS specification.

If there are both, they should be the same, right?
So, at least there should be a test whether this is the case and
raise a warning if not.

	Jan
-- 
Jan-Oliver Wagner               http://intevation.de/~jan/

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