Cart
|
[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Penance for misspent attributes
 Hi Sean. Sean McGrath wrote: > But isn't one there one, canonical, element-structure-plus-content view > dictated by XML 1.0 itself. i.e. that the syntactic form can be mechanically > morphed into a hierarchy view? Yes. That morphing is the first step of element (but not attribute!) processing > This jejune hierarchy view does not need to be hardcoded. However, the stuff > that is and is not *in* this hierarchy view dictates what can be in the process > view. Not exactly. A process will hardcode its specific data expectations, including a hierarchy view. Given that, the question is whether the XML document is then structured to the expectations of the process. We could ask that question in its converse form--should the process (and its internal data expectations) be constructed around a particular document model--which is what the advocates of vertical industry standard data vocabularies effectively prescribe. In either case we require detailed a priori understanding between--and, in effect, identical definitions of--process and document. This is what I call the enterprise network point of view, and it is pervasive in currently orthodox system design and is, in fact, the fundamental premise on which two-phase commit transaction processing depends. I have often (!) suggested that we are now in a position to embrace a different view, which I call the internetwork premise: that in being connected as an internetwork, homogenous networks remain internally homogenous, but an addressing scheme is overlaid on them which allows any node on any of those constituent networks to address directly any other node of the internetwork. What is lost, in gaining this direct node-to-node addressing, is the intimate knowledge which nodes on an homogenous enterprise network have of one another by virtue of the data structures, and the processes exactly fitted to those data structures, which they share. This view of the network vs. internetwork context of XML processing is broader than the original topic of this thread, though I believe that it is helpful in understanding the different sorts of processing, and thereby the different sorts of data structures, which a comprehensive general purpose XML processing model requires. You return below to a narrower view of the nature of XML processing, without consideration of this network/internetwork context: > This approach is, I think, where Charles Goldfarb et al. were going with > "structure controlled" versus "markup aware" SGML processors. The former took > the element-structure-plus-content view as their point of departure. (A > generation of these things became known as ESIS processors). Actually, this distinction is at least as old as the design of the Jacquard loom: does the programming operate fundamentally from the processor's structural knowledge of itself or from a template model of the output product. The principal point which I want to make is that attributes are the 'natural' way to represent--and attribute-based processing the natural way to execute--the "markup aware", just as elements, and element-specific processing, are best suited to "structure controlled" processes. The larger point is that general purpose markup processing permits both in the handling of the same document, and that there are significant advantages in using each sort of processing to its greatest advantage by not muddying the distinctions of the two. Respectfully, Walter Perry 
|
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! 
Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|
|||||||||
