"Schnitzer, Jeff" <[EMAIL PROTECTED]> writes: > Velocity produces text that must be parsed to perform XSLT transforms. > This new approach starts immediately with SAX events. Unlike a > hypothetical "saxify", it doesn't require fully navigating the source > object graph. Cool.
yes, I think so too. in fact, I'd say that this might be the biggest win to this approach. > The downside is that it introduces yet another templating language > syntax. What about borrowing the syntax of XSLT? Presumably your web > developers are already using XSLT to handle the outgoing sax events, it > would be nice if they could leverage their existing knowledge. I agree, and have given quite a bit of thought to exactly this solution. but I don't think it'd work, at least not in a way that would meet my initial requirements. first, XSLT is needlessly verbose. I don't want to have to say <xsl:value-of select='...'/> every time I want to refer to a value. second, and more importantly, it doesn't really solve the problem. the key piece is something to allow you to refer to objects/properties/methods from within the template. that is, you want to be able to easily cross the boundary between the template language and the "host" language. I could think of only two ways of doing this in XSLT 1) write an XSLT extention function, to be used as in <xsl:template match=''> ... <a> <xsl:attribute name='href'> <xsl:value-of select='ext:expr(model.price)'/> </xsl:attribute> ... </a> </xsl:template> but that's waaaaay too verbose, and doesn't really solve anything anyhow, because you've still got a mini-expression language (e.g. "model.price"). 2) domify the graph of potentially reachable objects, and use the document() function plus a suitable URL resolver to find access the objects from the stylesheet. that also seemed too awkward. the bottom line is that the expression language used in XSLT is XPath, which is an incredibly powerful and useful language, if you happen to be applying it to something that fits with the XPath data model. this didn't seem to be the case to me at the time, although XPath 2.0 looks like it might come closer. I wanted something that would be both fast (execution-wise) and relatively easy to explain to programmers/designers of moderate experience level. I've been pretty happy with it so far on both counts. the app in question exhibits snappy performance (although I have done no testing to validate this) and people have picked up on the ideas pretty easily. on a somewhat off-topic note, I'll say that when I first considered doing this my instinctive reaction was: "Please! Not another Java web framework!". But on further consideration, I don't think this critisicm was really valid. Really, it's just a recycling/repackging of various systems already available (Maverick, OGNL, "SAX"). More importantly, it used to be, back before I became someone who designs applications exclusively for the web (sigh), that I wasn't afraid of designing application-specific "little languages". This approach was considered a powerful tool for solving problems in a general way. anyhow, maybe the best thing would be for me to clean things up, put the code+examples someplace public, and let people take a look. I'll do this and let the list know when it's available. -- joe ------------------------------------------------------- This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 Project Admins to receive an Apple iPod Mini FREE for your judgement on who ports your project to Linux PPC the best. Sponsored by IBM. Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php [INVALID FOOTER]