[Zope-CMF] Re: Working with Zope 3 skin layers

[Charlie Clark]

Am 27.05.2008 um 16:48 schrieb Philipp von Weitershausen:

> Right. This will look up the 'detail.html' view for (context,  
> request). Now it depends on what layers the request has applied to.  
> Unless you've changed anything in the default skin configuration, it  
> will have Zope's default skin. Since the 'detail.html' view above  
> wasn't registered for the default layer but for soemthing else, it's  
> not found.
>
>>    <browser:page
>>        for="Products.Charlie.event.interfaces.IEventDetail"
>>        name="detail.html"
>>        template="detail.pt"
>>        class=".detail.DetailEdit"
>>        permission="cmf.ModifyPortalContent"
>>    />
>> is fine with /++skin++charlie/@@detail.html
>
> Yup, because if you don't specificy a layer explicitly,  
> <browser:page /> will register a view for IDefaultBrowserLayer. Your  
> charlie skin probably inherits from IDefaultBrowserLayer (either  
> directly or indirectly). That's why this works.
>
>> Of course, this ties in with what I get from Zope - that the  
>> adapter can't be found. I suspect I've misunderstood something  
>> fundamental on how views work with layers.
>
> My book has a large section devoted to this. :)

I know. You're book is probably the most referred to technical book I  
have! Very lucky that it was released as hard back. I've read the  
section a couple of times and while I think I understand the  
underlying mechanism...

What I think is still confusing me is:
1) I have created my dedicated skin
2) I have registered a view for that skin

I assumed that by registering the view for the skin, the view would  
automatically use the right layer when called. The effect being much  
the same as a customised view in a CMF layer: higher up the chain  
takes precedence. But it seems that this is not the case: unless it is  
set otherwise Zope will use the default skin. Is it possible to get  
individual views to use different skins without using ++skin++ in the  
URL?

>> Regarding CMFDefault - all views are registered explicitly for  
>> ICMFDefaultSkin but I think this isn't necessary as this is  
>> configured as the default skin.
>
> No, it *is* necessary, because the default skin can always change.  
> In fact, nearly every application (in the Zope 3 world) sets the  
> default skin (otherwise you'd need those hideous ++skin++ things in  
> all URLs).
>
> Also, by explicitly putting all views on the ICMFDefaultSkin layer,  
> those views are only there if your skin interface inherits from  
> ICMFDefaultSkin. Which means you can easily "switch off" those CMF  
> views by not including ICMFDefaultSkin. For some people this is an  
> important use case.


Wouldn't that raise an error on startup if ICMFDefaultSkin isn't  
found? Or how do you "not include" ICMFDefaultSkin? Using overrides?

Thanks for the help.

Charlie

PS: in your book the appendix to ZCML browser:defaultSkin says "see  
browser:skin". This has been deprecated, I think.

--
Charlie Clark
Helmholtzstr. 20
Düsseldorf
D- 40215
Tel: +49-211-938-5360
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