[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Didier's labs: experiments with xinclude - corrections
Hi, Excuse me for the last post that has several typos. I pressed the wrong key and the message was sent without a previous proofread. So here is a new one. Under the overall theme of information integration and information set (GROVE). I made an xinclude interpreter and encountered some problems. This report states some of the results concerning these xinclude experiments. Experiment protocol: -------------------- The xinclude interpreter behaves as requested by the W3C Working draft (ref: http://www.w3.org/TR/xinclude ). The xinclude construct has been used to include, in an XML document: a) results of SQL requests (i.e. XML documents) b) results of requests to news feed engines (moreover.com and On24.com services), c) non-structured or semi-structured data indexing engines requests (Thunderstorm, AltaVista with some wrapper code that returns an XML document for each query) d) results of HTTP requests to obtain an xml document or an XML fragment (HTTP 1.1 or WebDAV). To create the XML fragment, I had to include an xpointer interpreter to the xinclude engine . The tested XML documents contained only one xinclude request at a time since, parallel requests are not yet implemented in the Xinclude interpreter (reserved for the next step). It is pre-conceived that it is to the implementer's responsability to resolve in the most optimal way any parallel xinclude. This last feature should not affect the declarative format of the xinclude construct. Issues: ------- For any XML document accessible through a simple URL, the construct does not pose any problems. When the included document or document fragment is the result of a more sophisticated query, the construct poses some readability problems. Furthermore, the actual construct poses some limitation problems and is a bit out of synch with current XML developements. For instance, to do some sql requests I had to flatten out an sql request into a single string and make it to fit into a single line string. In fact, a majority of sql queries are more readable when expressed on several lines. On the other hand, a more severe experimented limitation is when I needed to do some requests with the HTTP POST method to an engine that replies with XML documents. I wasn't able to include a fragment with such method (using the xinclude construct). Proposed solution: ------------------ The actual xinclude query universe is restricted solely to accessing documents with URLs and does not take into account the possibility to do requests like, for instance, an HTTP POST request. The actual xinclude construct is then limited to, as an example, the HTTP GET method or to any protocol that can be expressed with a single URL. Several systems currently "a work in progress" in the e-commerce land take - as input for a request - an XML document through an HTTP POST method and reply with an XML document. The proposed solution is to allow the xinclude construct to allow <xinclude:include> elements' data content. The data content may then contain (a) a structured or semi-structured request, a multi-line request (such as sql) or any valid query. If the privileged protocol is HTTP, then, the data content would be interpreted as an HTTP POST content. Thus a construct like <xinclude:include href="http://www.mydomain.com/MyEngine"> select wheel, spike, brake from my_bike-database where wheel="Mavic" and break="shimano" </xinclude> Would result into an HTTP POST method targeted to the gizmo located at "http://www.mydomain.com/MyEngine" and which returns either an XML document or an XML document fragment. This latter is then inserted into the information set. Now back to the labs, I have some lines of codes screaming for some attention. Do you ear them? :-)) Cheers Didier PH Martin ---------------------------------------------- Email: martind@n... Conferences: XML Europe (http://www.gca.org) Book: XML Professional (http://www.wrox.com) column: Style Matters (http://www.xml.com) Products: http://www.netfolder.com *************************************************************************** This is xml-dev, the mailing list for XML developers. To unsubscribe, mailto:majordomo@x...&BODY=unsubscribe%20xml-dev List archives are available at http://xml.org/archives/xml-dev/ ***************************************************************************
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