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Subject: RE: Worry about using lexical order for preferences.
Looks like xerces provides the elements in a way that is compatible with using lexical order when using the methods and datastructures Chris mentioned. > -----Original Message----- > From: Moberg, Dale > Sent: Tuesday, January 30, 2001 9:59 AM > To: 'christopher ferris' > Cc: firstname.lastname@example.org > Subject: RE: Worry about using lexical order for preferences. > > > OK, lexical order is not always preserved so I thought > it was worth noting. I have not checked how the > getElementsbyTagName is implemented yet (though > my code is using it...) I will take a look at what > it does on the sample registry CPP and see > whether it adheres to the spec you > mention. Still seems like we are being awfully > minimalistic here, but maybe we can get by. > > Dale > > > > -----Original Message----- > > From: christopher ferris [mailto:email@example.com] > > Sent: Tuesday, January 30, 2001 9:48 AM > > To: Moberg, Dale > > Cc: firstname.lastname@example.org > > Subject: Re: Worry about using lexical order for preferences. > > > > > > Dale, > > > > A NodeList is an ordered collection. There are DOM methods > > that return a NodeList such as: > > > > getElementsByTagName > > Returns a NodeList of all descendant Elements with a > > given tag name, in the order in which they are encountered > > in a preorder traversal of this Element tree. > > > > From the DOM level 2 spec: > > > > "The DOM also specifies a NodeList interface to handle ordered > > lists of Nodes, such as the children of a Node, or the > > elements returned by the getElementsByTagName method of the > > Element interface, and also a NamedNodeMap interface to handle > > unordered sets of nodes referenced by their name attribute, > > such as the attributes of an Element." > > > > Note that order of attributes is "not significant" as per the > > XML 1.0 specification: > > http://www.w3.org/TR/2000/REC-xml-20001006#sec-starttags > > > > Cheers, > > > > Chris > > > > "Moberg, Dale" wrote: > > > > > > Hi > > > > > > One idea under consideration in TPA WG is > > > to use the CPP lexical order for preferences > > > among those elements having duplicated > > > capabilities (such as several possible > > > delivery channels and so on). > > > > > > I noticed yesterday that a popular > > > implementation of DOM API in Java (Xerces) > > > has a number of methods returning > > > multiple elements that do not preserve > > > lexical order. For example, the "getAttributes" > > > method returns a NamedNodeMap > > > in which the nodes are alphabetically > > > ordered, so that index 0, for example, > > > returns the alphabetically first > > > attribute by name of attribute and not the > > > lexically first attribute (I guess > > > I'd better mention that lexical order here > > > just means the order in which > > > it occurs in the file/stream). > > > > > > So while I have not checked out every > > > method (and I think this will be a DOM > > > problem, because SAX callbacks do > > > follow lexical order as far as I can tell), > > > I am wondering whether we should > > > be more explicit about preference. Sorry > > > to add another item. > > > > > > (I should also mention that > > > DOM implementations will probably > > > be popular for dealing with CPP > > > processing because of the need to jump around > > > with IDs while figuring out whether > > > and how the capabilities match.) > > > > > > Dale Moberg > > >
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