[Tilecache] GetCapabilities document is not valid

Steven M. Ottens steven at minst.net
Tue Mar 4 09:48:29 EST 2008


Christopher Schmidt wrote:
> On Tue, Mar 04, 2008 at 10:01:33AM +0100, Holger Jaekel wrote:
>   
>> But the DTD says:
>>
>> <!-- Nested list of zero or more map Layers offered by this server. -->
>> <!ELEMENT Layer ( Name?, Title, Abstract?, KeywordList?, SRS*,
>>                   LatLonBoundingBox?, BoundingBox*, Dimension*, Extent*,
>>                   Attribution?, AuthorityURL*, Identifier*,
>> MetadataURL*, DataURL*,
>>                   FeatureListURL*, Style*, ScaleHint?, Layer* ) >
>>
>> So the section must have this structure:
>>     
Ok, my DTD skills aren't that developed, but what I understand of this 
(with the aid of eclipse) is that 'Title' is a just once attribute and 
as such required all the others are either optional (the ?-ones) or zero 
or more (the * ones) types. These two are not required and can be left 
out. So we only need to add a <Title> to the root layer and we are set.

Correct me if I'm wrong.

> Okay, so I'm confused.
>
> FIrst, I had a bunch of layers, with no external layer container. Then
> stvn came to the list and said "You can't do that", so I added an extra
> <layer> around the outside. That <Layer> doesn't have a name, title, or
> anything else: It's just a container. There's no information to be added
> there. 
>
> So, there's two possibilities here:
>  1. WMS doesn't need the <Layer> container. This is possible: I was told
>     it did, and I confirmed that other WMS servers used it.
>  2. TileCache needs to create a bogus layer with a name, title, srs,
>      boundingbox? That doesn't make sense to me. Which I think means the
>      answer is 1. Which means I should have been more diligent in
>      pushing back on stvn.
>   
Strangly enough I reported the bug because the getCapabilities failed to 
validate. Once the empty <Layer> tags were added it did validate, so I 
missed the apparent obligatory <Title> tag. Thanks for finding it.

Steven





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