[XBL] Complexity of XBL

Dear XBL experts,

This email comments on the 7 September 2006 LCWD of XBL 2.0.

As a general comment, I think the binding mechanism is really 
interesting but the specification requires complex algorithms which may 
not be needed in many scenarios. Among the complex algorithms:
- explicit/implicit inheritance: what will be the percentage of content 
really using this feature ?
- runtime behavior: the specification requires to be able to detach a 
binding. This means that the original structure of the bound element 
needs to be kept, thus an heavy memory usage.
- attach/regenerate bidings: this may require a lot of processing and 
the feature may not be heavily used.
- live binding and document: the specification says:
    "Dynamic changes to shadow content templates are reflected in 
bindings. (See: shadow content.)"
    "An imported binding document is live."
    "All of the nodes in the shadow tree are live."
    "Whenever the subtree of a template element is dynamically modified, 
any shadow trees that were constructed by cloning that element must be 
regenerated."
It also allows modifying the "extends" attribute. All this processing 
seems really heavy.
Has the WG evaluated the cost of all these features and weighted the 
cost versus benefits ? It would be very interesting to see the results.
Has the WG considered making simple profiles of this specification ?

Cyril Concolato

Received on Thursday, 7 December 2006 13:59:34 UTC