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Re[2]: sax or dom in XSLT procesing ?

2003-01-29 09:28:43
Hello Joseph,

Wednesday, January 29, 2003, 6:00:56 PM, you wrote:

thank for Oleg Tkachenko for this link
-- Also Elliotte Rusty Harold in his "Processing XML with Java" provides many
-- samples, e.g. see how to represent SQL table as SAX filter at
-- http://www.ibiblio.org/xml/books/xmljava/chapters/ch08s05.html.

its very useful variant, but last question is, if xalan read input
SAX document (represented as XMLReader) one time, and  scroll it FORWARD_ONLY ?

some of question is if
xslt processor (i use xalan) build full tree of data before start
transform ?

JK> Depends on the processor and how you've configured it.

JK> If you're reading from SAX, Xalan normally does build a full DTM model of 
JK> the source document immediately. It can be told to build that model 
JK> incrementally, as the stylesheet/xpath actually calls for nodes; see 
JK> Xalan's documentation for a discussion of the trade-offs in that approach.

JK> If you're reading from DOM, Xalan incrementally builds a DTM "proxy" to 
JK> access your DOM. This is lighter-weight than a complete DTM would be. It 
JK> still doesn't run as quickly as we'd like and burns more memory than we'd 
JK> like, and we're working on improvements to that section of the processor.

JK> See also archives of the Xalan mailing list, searching for the key words 
JK> "streaming", "pruning", and "filtering", to see past design discussion of 
JK> what we're doing now and some of what we're investigating as future 
JK> refinements to the model.


JK> Summary: If you already have a DOM in memory, use a DOMSource to pass that 
JK> to Xalan and let us Do The Right Thing. If you have some other type of 
JK> model in memory, your best bet is currently to serialize it to SAX and 
JK> hand us a SAXSource. If you don't already have a model in memory, your 
JK> best bet is to obtain/generate a SAX stream, wrap that in a SAXSource, and 
JK> let us read that.

JK> ______________________________________
JK> Joe Kesselman  / IBM Research


JK>  XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list




-- 
Best regards,
 Andrey                            mailto:solo(_at_)ibis(_dot_)odessa(_dot_)ua



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