X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=doc%2Frecordmodel-alvisxslt.xml;h=8eee9b945e25690bf962824ddb914766e78b1797;hb=7a1897c37a9fc946a3b44b10a46ed1eecdd3634a;hp=a322f74aa1282fbd16f2fab172db85aa273d1a54;hpb=495a66ecd5fb966a8bd52f95dc25cde9d673e569;p=idzebra-moved-to-github.git diff --git a/doc/recordmodel-alvisxslt.xml b/doc/recordmodel-alvisxslt.xml index a322f74..8eee9b9 100644 --- a/doc/recordmodel-alvisxslt.xml +++ b/doc/recordmodel-alvisxslt.xml @@ -1,41 +1,47 @@ - - ALVIS XML Record Model and Filter Module - + + ALVIS &xml; Record Model and Filter Module + + + + The functionality of this record model has been improved and + replaced by the DOM &xml; record model. See + . + + The record model described in this chapter applies to the fundamental, - structured XML + structured &xml; record type alvis, introduced in - . The ALVIS XML record model - is experimental, and it's inner workings might change in future - releases of the Zebra Information Server. + . This filter has been developed under the ALVIS project funded by the European Community under the "Information Society Technologies" - Programme (2002-2006). + Program (2002-2006). - +
ALVIS Record Filter - The experimental, loadable Alvis XM/XSLT filter module + The experimental, loadable Alvis &xml;/&xslt; filter module mod-alvis.so is packaged in the GNU/Debian package libidzebra1.4-mod-alvis. - It is invoked by the zebra configuration statement + It is invoked by the zebra.cfg configuration statement recordtype.xml: alvis.db/filter_alvis_conf.xml - on all data files with suffix .xml, where the - alvis XSLT filter config file is found in the - path db/filter_alvis_conf.xml + In this example on all data files with suffix + *.xml, where the + Alvis &xslt; filter configuration file is found in the + path db/filter_alvis_conf.xml. - The alvis XSLT filter config file must be - valid XML. It might look like this (used for indexing and display - of OAI harvested records): + The Alvis &xslt; filter configuration file must be + valid &xml;. It might look like this (This example is + used for indexing and display of &oai; harvested records): <?xml version="1.0" encoding="UTF-8"?> <schemaInfo> @@ -43,7 +49,7 @@ <schema name="index" identifier="http://indexdata.dk/zebra/xslt/1" stylesheet="xsl/oai2index.xsl" /> <schema name="dc" stylesheet="xsl/oai2dc.xsl" /> - <!-- use split level 2 when indexing whole OAI Record lists --> + <!-- use split level 2 when indexing whole &oai; Record lists --> <split level="2"/> </schemaInfo> @@ -56,47 +62,47 @@ names defined in the name attributes must be unique, these are the literal schema or element set names used in - SRW, - SRU and - Z39.50 protocol queries. - The pathes in the stylesheet attributes + &srw;, + &sru; and + &z3950; protocol queries. + The paths in the stylesheet attributes are relative to zebras working directory, or absolute to file system root. The <split level="2"/> decides where the - XML Reader shall split the + &xml; Reader shall split the collections of records into individual records, which then are - loaded into DOM, and have the indexing XSLT stylesheet applied. + loaded into &dom;, and have the indexing &xslt; stylesheet applied. - There must be exactly one indexing XSLT stylesheet, which is + There must be exactly one indexing &xslt; stylesheet, which is defined by the magic attribute identifier="http://indexdata.dk/zebra/xslt/1". - +
ALVIS Internal Record Representation - When indexing, an XML Reader is invoked to split the input - files into suitable record XML pieces. Each record piece is then - transformed to an XML DOM structire, which is essentially the - record model. Only XSLT transfomations can be applied during + When indexing, an &xml; Reader is invoked to split the input + files into suitable record &xml; pieces. Each record piece is then + transformed to an &xml; &dom; structure, which is essentially the + record model. Only &xslt; transformations can be applied during index, search and retrieval. Consequently, output formats are - restricted to whatever XSLT can deliver from the record XML - structure, be it other XML formats, HTML, or plain text. In case - you have libxslt1 running with EXSLT support, - you can use this functionality inside the alvis - filter configuraiton XSLT stylesheets. + restricted to whatever &xslt; can deliver from the record &xml; + structure, be it other &xml; formats, HTML, or plain text. In case + you have libxslt1 running with E&xslt; support, + you can use this functionality inside the Alvis + filter configuration &xslt; stylesheets. - +
- +
ALVIS Canonical Indexing Format - The output of the indexing XSLT stylesheets must contain + The output of the indexing &xslt; stylesheets must contain certain elements in the magic xmlns:z="http://indexdata.dk/zebra/xslt/1" - namespace. The output of the XSLT indexing transformation is then - parsed using DOM methods, and the contained instructions are + namespace. The output of the &xslt; indexing transformation is then + parsed using &dom; methods, and the contained instructions are performed on the magic elements and their subtrees. @@ -112,31 +118,32 @@ z:id="oai:JTRS:CP-3290---Volume-I" z:rank="47896" z:type="update"> - <z:index name="oai:identifier" type="0"> + <z:index name="oai_identifier" type="0"> oai:JTRS:CP-3290---Volume-I</z:index> - <z:index name="oai:datestamp" type="0">2004-07-09</z:index> - <z:index name="oai:setspec" type="0">jtrs</z:index> - <z:index name="dc:all" type="w"> - <z:index name="dc:title" type="w">Proceedings of the 4th + <z:index name="oai_datestamp" type="0">2004-07-09</z:index> + <z:index name="oai_setspec" type="0">jtrs</z:index> + <z:index name="dc_all" type="w"> + <z:index name="dc_title" type="w">Proceedings of the 4th International Conference and Exhibition: World Congress on Superconductivity - Volume I</z:index> - <z:index name="dc:creator" type="w">Kumar Krishen and *Calvin + <z:index name="dc_creator" type="w">Kumar Krishen and *Calvin Burnham, Editors</z:index> </z:index> </z:record> - This means the following: From the original XML file - one-record.xml (or from the XML record DOM of the + This means the following: From the original &xml; file + one-record.xml (or from the &xml; record &dom; of the same form coming from a splitted input file), the indexing - stylesheet produces an indexing XML record, which is defined by + stylesheet produces an indexing &xml; record, which is defined by the record element in the magic namespace xmlns:z="http://indexdata.dk/zebra/xslt/1". - Zebra uses the content of + &zebra; uses the content of z:id="oai:JTRS:CP-3290---Volume-I" as internal record ID, and - in case static ranking is set - the content of z:rank="47896" as static rank. Following the - discussion in XXX we see that this records is internally ordered + discussion in + we see that this records is internally ordered lexicographically according to the value of the string oai:JTRS:CP-3290---Volume-I47896. The type of action performed during indexing is defined by @@ -144,56 +151,303 @@ insert, update, and delete. - Then the following literal indexes are constructed: + In this example, the following literal indexes are constructed: - oai:identifier - oai:datestamp - oai:setspec - dc:all - dc:title - dc:creator + oai_identifier + oai_datestamp + oai_setspec + dc_all + dc_title + dc_creator where the indexing type is defined in the - type attribute (any value from the standard config - filedefault.idx will do). Finally, any + type attribute + (any value from the standard configuration + file default.idx will do). Finally, any text() node content recursively contained inside the index will be filtered through the appropriate charmap for character normalization, and will be inserted in the index. - Notice that there are no .abs, - .est, .map, or other GRS-1 - filter configuration files involves in this process. Notice also, - that the names and types of the indexes can be defined in the - indexing XSLT stylesheet dynamically according to - content in the original XML records, which has - oppertunities for great power and great disaster. + Specific to this example, we see that the single word + oai:JTRS:CP-3290---Volume-I will be literal, + byte for byte without any form of character normalization, + inserted into the index named oai:identifier, + the text + Kumar Krishen and *Calvin Burnham, Editors + will be inserted using the w character + normalization defined in default.idx into + the index dc:creator (that is, after character + normalization the index will keep the inidividual words + kumar, krishen, + and, calvin, + burnham, and editors), and + finally both the texts + Proceedings of the 4th International Conference and Exhibition: + World Congress on Superconductivity - Volume I + and + Kumar Krishen and *Calvin Burnham, Editors + will be inserted into the index dc:all using + the same character normalization map w. + + + Finally, this example configuration can be queried using &pqf; + queries, either transported by &z3950;, (here using a yaz-client) + + open localhost:9999 + Z> elem dc + Z> form xml + Z> + Z> f @attr 1=dc_creator Kumar + Z> scan @attr 1=dc_creator adam + Z> + Z> f @attr 1=dc_title @attr 4=2 "proceeding congress superconductivity" + Z> scan @attr 1=dc_title abc + ]]> + + or the proprietary + extentions x-pquery and + x-pScanClause to + &sru;, and &srw; + + + + See for more information on &sru;/&srw; + configuration, and or the &yaz; + &cql; section + for the details or the &yaz; frontend server. - - + + Notice that there are no *.abs, + *.est, *.map, or other &grs1; + filter configuration files involves in this process, and that the + literal index names are used during search and retrieval. + +
+
- +
ALVIS Record Model Configuration - +
ALVIS Indexing Configuration - FIXME + + As mentioned above, there can be only one indexing + stylesheet, and configuration of the indexing process is a synonym + of writing an &xslt; stylesheet which produces &xml; output containing the + magic elements discussed in + . + Obviously, there are million of different ways to accomplish this + task, and some comments and code snippets are in order to lead + our paduans on the right track to the good side of the force. + + + Stylesheets can be written in the pull or + the push style: pull + means that the output &xml; structure is taken as starting point of + the internal structure of the &xslt; stylesheet, and portions of + the input &xml; are pulled out and inserted + into the right spots of the output &xml; structure. On the other + side, push &xslt; stylesheets are recursavly + calling their template definitions, a process which is commanded + by the input &xml; structure, and avake to produce some output &xml; + whenever some special conditions in the input styelsheets are + met. The pull type is well-suited for input + &xml; with strong and well-defined structure and semantcs, like the + following &oai; indexing example, whereas the + push type might be the only possible way to + sort out deeply recursive input &xml; formats. + + + A pull stylesheet example used to index + &oai; harvested records could use some of the following template + definitions: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ]]> + + + + Notice also, + that the names and types of the indexes can be defined in the + indexing &xslt; stylesheet dynamically according to + content in the original &xml; records, which has + opportunities for great power and wizardery as well as grande + disaster. - FIXME + + The following excerpt of a push stylesheet + might + be a good idea according to your strict control of the &xml; + input format (due to rigerours checking against well-defined and + tight RelaxNG or &xml; Schema's, for example): + + + + + + + ]]> + + This template creates indexes which have the name of the working + node of any input &xml; file, and assigns a '1' to the index. + The example query + find @attr 1=xyz 1 + finds all files which contain at least one + xyz &xml; element. In case you can not control + which element names the input files contain, you might ask for + disaster and bad karma using this technique. - FIXME + + One variation over the theme dynamically created + indexes will definitely be unwise: + + + + + + + + + + + + + + + + + + ]]> + + Don't be tempted to cross + the line to the dark side of the force, paduan; this leads + to suffering and pain, and universal + disentigration of your project schedule. - +
- +
ALVIS Exchange Formats - FIXME - + + An exchange format can be anything which can be the outcome of an + &xslt; transformation, as far as the stylesheet is registered in + the main Alvis &xslt; filter configuration file, see + . + In principle anything that can be expressed in &xml;, HTML, and + TEXT can be the output of a schema or + element set directive during search, as long as + the information comes from the + original input record &xml; &dom; tree + (and not the transformed and indexed &xml;!!). + + + In addition, internal administrative information from the &zebra; + indexer can be accessed during record retrieval. The following + example is a summary of the possibilities: + + + + + + + + + + + + + + + + + + + + + + + ]]> + + + +
+ +
+ ALVIS Filter &oai; Indexing Example + + The sourcecode tarball contains a working Alvis filter example in + the directory examples/alvis-oai/, which + should get you started. + + + More example data can be harvested from any &oai; complient server, + see details at the &oai; + + http://www.openarchives.org/ web site, and the community + links at + + http://www.openarchives.org/community/index.html. + There is a tutorial + found at + + http://www.oaforum.org/tutorial/. + +
- +
@@ -201,7 +455,7 @@