[Seaside] Difference WAStaticHtmlCanvas >< WAHtmlCanvas

Claus Kick claus_kick at web.de
Wed Mar 12 17:45:31 UTC 2008

Ramon Leon wrote:

>>Today I had a look at The WACanvas hierarchy, but I do not 
>>understand the difference between WAStaticHtmlCanvas and WAHtmlCanvas.

> Look closer, WAHtmlCanvas is an abstract class, #document must be overridden
> by subclasses. 

Ok, missed that. I think I read the arrow-down symbol as arrow-up.

> They are mostly the same thing, WAStaticHtmlCanvas is just a
> concrete implementation for it.  

One thing to mention there: the class comments should reflect that then.

 > If WAStaticHtmlCanvas didn't exist and you
> used WAHtmlCanvas directly, you'd have the WARenderCanvas inheriting from an
> implementation class.  

My understanding was: WAHtmlCanvas provides the basic tags and 
WARenderCanvas adds the callback items.

 > With the current implementation, WAStaticHtmlCanvas
> is free to grow without messing up WARenderCanvas, it's cleaner the way it
> is, one abstract class with two concrete implementations.  

I agree, it is cleaner that way.

> I'm looking at 2.8 btw, it may have changed in 2.9.  It does look like
> #textArea needs pushed up, it's the same in both subclasses.

I was wondering about that as well, but forgot to ask about it.  Doesnt 
it need actually to be deleted in WAStaticHtmlCanvas? The other input 
elements are all in WARenderCanvas.


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