[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: ModSAX (SAX 1.1) Proposal
Hello, Thank you for your response and the example you provided. The rationale you provide for having a marker interface is good in that it provides full generality -- *any* kind of handler can be attached to the parser to do *any* kind of thing. Ok. My feeling is that while there may be a slew of PingHandler -like handlers which will do who-knows-what, there will also be a (more common and useful!) set of *Handlers which will do the same kind of things; it would be unfortunate if handlers which did the same work (e.g., validation) had different interfaces simply because no structure was provided for the implementors to follow. (Will J Clark's validation handler have the same interface as IBM's? unlikely. Will they be interchangeable? -- iff my parser knows about both of them...). I see two ways around this difficulty. The first is to define a set of subinterfaces of ModHandler which are adapted for particular uses. This way we have a shared known set of Handlers for our most common uses. Another means to the same end is to have a mechanism by which a parser can lookup (perhaps using the URI mechanism you and D. Brickley have been discussing) specific types of *ModHandlers. Thus a parser can learn about a particular kind of handler on the fly. Both approaches have limitations, I know. The first is difficult because it's hard to define those interfaces a priori. The second, at least looking at CORBA's Dynamic Invocation mechanism as an example, tends to be overly complex and messy. For these reasons, I could certainly see deciding against them, leading us back to (something like) what you proposed originally... but it seems to me both possible and desirable to provide *some* structure in the form of pre-defined ModHandlers. Best Regards, Tito. xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1 To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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