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[ubl-ndrsc] Elements vs. attributes: discussion kickoff

  • 1.  [ubl-ndrsc] Elements vs. attributes: discussion kickoff

    Posted 01-30-2002 11:48
    One of the more critical areas we need to decide is "elements vs. 
    attributes".  Gunther's position paper is here (he's going to update it soon):
    
    http://www.oasis-open.org/committees/ubl/ndrsc/pos/draft-stuhec-elemvsattrib-01.doc
    
    Here are a few unorganized thoughts to get the discussion going; everyone, 
    please respond with your thoughts, and I'll try to formulate votable 
    questions as we go:
    
    I think the analysis in this paper about advantages and disadvantages of 
    attributes is mostly on target (I have a few quibbles that I'll try to 
    write up soon).  I'd like to see the advantages and disadvantages of 
    elements described fully in similar fashion.
    
    I wonder, though, if the draft proposal in this paper favors attributes too 
    heavily.  With the advent of XSD, there is little you can do in attributes 
    that you can't do in elements -- even default values can be assigned to 
    elements that have a simple type.  And even the code list case (which seems 
    like an obvious candidate for attributes because it often uses a closed set 
    of values) isn't crystal clear, because we know we need to add all kinds of 
    metadata and mechanisms to code lists to make them work.
    
    Finally, I wonder if this paper can be expanded to explore the question of 
    empty elements too.  This topic came up in the F2F last week (are empty 
    elements "leaf nodes"? should they be used only as "attribute hangers" or 
    also as presence/absence boolean indicators? how should we name them? 
    should we allow them at all?).
    
    	Eve
    --
    Eve Maler                                    +1 781 442 3190
    Sun Microsystems XML Technology Center   eve.maler @ sun.com