A naive implementation of the document() function is likely to do this. However happily, by implementing the javax.xml.transform.URIResolver interface [1], and setting this on the Tranformer using setURIResolver [2] you can easily plug in a simple cache (e.g. hash of URL versus retrieved content) that avoid multiple network overheads.
I have a sample implementation and simple test harness if anyone wants it. Cheers, L. [1]. http://java.sun.com/j2se/1.4/docs/api/javax/xml/transform/URIResolver.html [2]. http://java.sun.com/j2se/1.4/docs/api/javax/xml/transform/Transformer.html#setURIResolver(javax.xml. transform.URIResolver) > -----Original Message----- > From: Ilya A. Kriveshko [mailto:ilya@;kaon.com] > Sent: 05 November 2002 14:33 > To: [EMAIL PROTECTED] > Subject: Poor performance of document() in XSL [Was: Re: simpel cocoon > question] > > > SAXESS - Hussayn Dabbous wrote: > > > <snip/> > > But you also could do it directly within the xslt context: > > You can use the document() function in your XSLT-file. > > This function allows you to refer to data contained within > > another XML-file. This is completely decoupled from cocoon > > though. It's more about how to work with XSLT: > > <snip/> > > > In the past I have encountered a nasty performance problem with document(). > For example, when you declare an xsl variable that gets its value from a > document(), > and then use its value several times throughout the stylesheet, the URI > of the document > gets hist as many times as there are references to that variable. I.e. > the xsl variable > does not store the XML fragment it was given at the variable definition > time, but > merely stores the XPath string and then resolves it every time it's > referenced. > This may or may not be true for XPath expressions that do not contain > document() > as well. Does anyone know for sure? > > Example: > > <xsl:variable name="test-me" > select="document('cocoon:/gimme-sumthn')/sumthn/in/@there"/> > > <xsl:template match="/"> > <this-is-just-a-test> > <xsl:value-of select="$test-me"/> > <xsl:value-of select="$test-me"/> > <xsl:value-of select="$test-me"/> > </this-is-just-a-test> > </xsl:template> > > When using Xalan, this example will cause the Cocoon pipeline that > is responsible for "gimme-sumthn" to be hit three times. I say, > document() is good for rapid prototyping, but is a poor choice for final > deployment for performance reasons. Use aggregation instead. > > +2c > -- > Ilya > > > > > > --------------------------------------------------------------------- > Please check that your question has not already been answered in the > FAQ before posting. <http://xml.apache.org/cocoon/faq/index.html> > > To unsubscribe, e-mail: <[EMAIL PROTECTED]> > For additional commands, e-mail: <[EMAIL PROTECTED]> > --------------------------------------------------------------------- Please check that your question has not already been answered in the FAQ before posting. <http://xml.apache.org/cocoon/faq/index.html> To unsubscribe, e-mail: <[EMAIL PROTECTED]> For additional commands, e-mail: <[EMAIL PROTECTED]>
