[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: why split? [was RE: XSL intent survey]
Hi Guy, OK I understand. What you call a proxy is, in fact, _a MIME type handler which is like a protocol handler but specialized to handle a particular MIME type. The concept of MIME type handler in modzilla is actually solely related to plug-ins but there is work in progress to create the same kind of functionality as Ms Explorer has. A filter that receives the stream and can do transform to the stream content and give it back to the browser with its new MIME type and let it render this MIME type (which may or not involve plug-ins, activeX or applets). It means that, for instance, you receive a XML MIME type and the MIME handler returns to the browser a HTML or RTF MIME type. So to speak, the transform is not so much a structural transformation as a MIME type transformation. Status: MS explorer already has this feature. Modzilla has this feature in construction. To use a Java applet to do the job requires that you include the applet with your document and get that document embedded in a HTML document. Thus the HTML document act as a carrier of a) the applet, b) the XML document. Which is probably not a good way to package a XML document :-) otherwise, why not transfer it in already transformed in HTML format (except to reduce the server workload but to increase the bandwidth and latency load). to get an applet or Active X component that do a call to the server to do the transform would also be not very efficient. I hope that other software manufacturer will not use applet, active X or plug-in to implement their XSL interpreter. At least not with the current philosophy of having these components part of a HTML documents and have them do the process within the HTML document context. The best solution (in certain contexts)seems to be the "MIME handler" having the behavior described above. There is one drawback however, and we experimented it with DSSSL. When a big document is downloaded (we used the XML Hamlet document from Jon Bosak and technical ATA 100 docs, a SGML standard used in the aerospace industry) it takes several seconds to be interpreted and transformed (always here only a rendering transformation not a structural one). This process could be accelerated with a cache mechanism like implemented with certain proxies. That is why, I thought at first, that you were talking of proxies - because of their caching capability. Thus, if the "MIME handler" maintains a cache of already transformed documents, it could accelerate the translation process. In fact, we discovered with a network usage that more than one person could have the same document translated more than once (obvious you say? :-) you're right). An intelligent proxy could not only keep in a buffer documents (like they do today) but also transform them when required (like for instance XML->HTML), keep the transformed document in the cache for later usage. At first, I thought that this is what you meant as a major reason for a proxy with added transformation capabilities. Do somebody else got similar experience with long documents? We experimented with some technical documents like, for instance ATA100 based documents that can easily be transformed from SGML to XML. As you know, technical documents could be quite big sometimes. We got with microsoft XSL interpreter(written in C++ and faster than other Java based XSL translator, no offence, its just a fact and do not indicate any inclinations) , in certain case several seconds interpretation time before the rendering occurred. We then got he usual HTML interpretation and rendering delays which are not big numbers but still there. Users found the process slow on 166 Mhz machines. On 300 Mhz machines they couldn't notice the difference and in human time perception wasn't perceived as slow :-) We got the same problem with DSSSL transformation. So it seems that network with a big bunch of 166 or slower machines may benefit from a proxy based mechanism. When we checked commercial proxies, we discovered that they do not have the concept of MIME handlers. In fact, are just, buffers and not transformation tools. I guess we were a bit too fast for this market :-). Question: maybe we didn't searched well and there is somewhere the pearl that we need. If someone from this list knows one, can you send us a link? do anyone knows a proxy server that can have kind of plug ins to do document transformation - like for example - MIME handlers? Didier PH Martin mailto:martind@xxxxxxxxxxxxx http://www.netfolder.com > -----Original Message----- > From: owner-xsl-list@xxxxxxxxxxxxxxxx > [mailto:owner-xsl-list@xxxxxxxxxxxxxxxx]On Behalf Of > Guy_Murphy@xxxxxxxxxx > Sent: Friday, November 27, 1998 5:37 AM > To: xsl-list@xxxxxxxxxxxxxxxx > Subject: RE: why split? [was RE: XSL intent survey] > > > Hi. > > I think the field got muddied over the term "proxy"... acting as a proxy > with a smal "p" not a network Proxy Server... sorry if I confused anybody > :) > > The reason why a proxy is desirable (or an ActiveX component, it's the > fnctionality not the tech that's important) is because I produce largely > dHTML sites, and it's highly desirable to be able to "squirt" the results > of server mark-up into a chosen element. The MS Remote Scripting proxy > makes it possible to execute a JScript function on a server, and recieve > the result syncronously or asyncronously through the proxy as if > it where a > local function return. ie... > > myDiv.innerHTML = myRSFunction(); > > Now the proxy is Java so it's possible to utilise RS on any browser > supporting JavaScript and Java.... It would be nice to have an XSL parser > moulded in a similar fashion. At the moment with have this > functionality in > IE5, but I see no reason why it could become common to impliment this on a > wide range of browsers. > > Cheers > Guy > > > > > > xsl-list@xxxxxxxxxxxxxxxx on 11/26/98 10:55:09 PM > > To: xsl-list@xxxxxxxxxxxxxxxx > cc: (bcc: Guy Murphy/UK/MAID) > Subject: RE: why split? [was RE: XSL intent survey] > > > > > Hi, > So let me try to understand your point. Why do you need a proxy and not a > server based interpreter? > A) is it because your server deserve several sub nets and you want to off > load the server by having a proxy server on each net? > b) your main target is Modzilla and actually there is no mechanisms > (already > completed) to add a XSL processor to the browser and therefore your > solution > is to add a proxy to the browser? > c) you want to cache and pre-translate XML documents into, let's > say, HTML? > Your answer could help us understand your pre-requisites > cheers > Didier PH Martin > mailto:martind@xxxxxxxxxxxxx > http://www.netfolder.com > > -----Original Message----- > > From: owner-xsl-list@xxxxxxxxxxxxxxxx > > [mailto:owner-xsl-list@xxxxxxxxxxxxxxxx]On Behalf Of > > Guy_Murphy@xxxxxxxxxx > > Sent: Thursday, November 26, 1998 11:19 AM > > To: xsl-list@xxxxxxxxxxxxxxxx > > Subject: RE: why split? [was RE: XSL intent survey] > > > > > > Hi. > > > > Sufficient for what purpose? Your purpose?... not mine :) > > > > I want a proxy, or at least the scriptable object currently available. > > Direct browsing is one mechanism, but not always ideal. > > > > Cheers > > Guy. > > > > > > > > > > xsl-list@xxxxxxxxxxxxxxxx on 11/26/98 04:11:37 PM > > > > To: xsl-list@xxxxxxxxxxxxxxxx > > cc: (bcc: Guy Murphy/UK/MAID) > > Subject: RE: why split? [was RE: XSL intent survey] > > > > > > > > > > [SNIP] > > Thus, there is no need to implement a XSL, DSSSL or xxxxL processor as a > > proxy, just a browser's MIME filter is sufficient. > > [SNIP] > > > > > > > > XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list > > > > XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list > > > > > > > XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list > XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
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