Specify more precisely which children under atom:feed may be unordered in The Atom Syndication Format.




The 0.3 Atom format text around element order of the the children of the atom:feed element is under constrained and should be modified.


From 0.3 section 4 para 2 [WWW]

   Ordering of the element children of atom:feed element MUST NOT be considered significant.

Change the statement quoted in section 4 to read:

The purpose of this proposal is to specify more precisely which children under atom:feed may be unordered (namely the atom:entry children). By doing so an important distinction is preserved between between lexical (XML) and application (Atom) issues.


Spec text.


As a matter of syntax (and some XML programming models), element order is intrinsic to XML. Among other things, the proposed wording makes specifying a schema that isn't over constrained feasible without having to enumerate all possible orders.

Past discussions around ordering seem concerned on the order of the atom:entry children in an atom:feed, not all elements under atom:feed. This concern can be summed with the question, "what's the natural order of atom:entry children?". That is an application (Atom) matter, not a lexical (XML) matter - the two can and should be kept distinct.

The matter of order in general might also extends to atom:entry which is similarly underconstrained but the intention is to deal with that seperately.

Advantage of Order

DTD and XSD based tools work better when element are ordered. Unordering of elements means that tools like Microsoft's XSD.exe and WSDL.exe can no longer accurately describe Atom. -- RandyCharlesMorin

See previous Wiki discussions on XsdFriendly.