small data in the large with oppidum
TRANSCRIPT
Acknowledgements MEDIA research Group
Small Data in the large with OppidumXML web development with Oppidum and eXist-DB
Presented at XML London 2013 (read the full article)
Stéphane Sire
Contact: [email protected] - Oppidoc
Christine Vanoirbeek
Contact: [email protected]
IntroductionPresentation vs. semantic
“ On the left, what browsers see. On the right, what humans see. Can webridge the gap so browsers see more of what we see? ”
Source W3CRDFa 1.1 Primer Rich Structured Data Markup for Web Documents
Small data applicationsdocument structure (sections, paragraphs, lists, etc.)
truffled with structured data inside
edit | xml | hide | previewXML Prague 2010Introduction of the AXEL Javascript library for XML authoring in thebrowser
S. Sire, C. Vanoirbeek, V. Quint, C. Roisin,Authoring XML all the Time, Everywhere and by Everyone. InProceedings of XML Prague 2010, pages 125 - 149 , Institute forTheoretical Computer Science, 14/03/2010
Self-service demo:
click a first time on “edit” to transform the bibliographic reference into an editor
click on “xml” (resp. “hide”) to show (resp. hide) its current XML content
click on “preview” to hide / show editor structure editing controls
<References> <Publication Date="2010-03-14"> <Authors> <Author> <Name>S. Sire</Name>
</Author> <Author> <Name>C. Vanoirbeek</Name> </Author> <Author> <Name>V. Quint</Name> </Author> <Author> <Name>C. Roisin</Name> </Author> </Authors> <Title>Authoring XML all the Time, Everywhere and by Everyone</Title> <Conference>Proceedings of XML Prague 2010</Conference> <Pages> <Start>125</Start> <End>149</End> </Pages> <Location>Institute for Theoretical Computer Science</Location> </Publication></References>
Motivation: full XML stack
XML web developmentLanguages (W3C)
XPath => XQuery, XSLT
XForms XTiger XML (Adaptable XML Editing Library)
Native XML databases
eXist-DB, Sausalito, baseX, Marklogic
XRX programming style and 2/3 architectures
But still very few application frameworks !
RESTXQ, EXPath
Orbeon Forms, Oppidum
Oppidum PrinciplesA unique XML file to represent the application architecture
the mapping associates each REST resource from the application with arendering pipeline
Oppidum PipelineLimited to 3 steps (KISS-principle)
a model implemented as an XQuery script
a (optional) view implemented as an XSLT transformation
an (optional) epilogue implemented as a unique XQuery script called epilogue.xql
sample :
Article Editing ApplicationFully specificed by 6 pipelines
Mapping file example
<collection name="articles"> <item> => articles/xml-london[.xml] <access> <rule action="edit POST" role="g:authors" message="author"/> </access> <model src="oppidum:actions/read.xql"/> <view src="article/article2html.xsl"/> <action name="edit"> => articles/xml-london/edit <model src="actions/edit.xql"/> <view src="views/edit.xsl"/> </action> <action name="POST"> => POST articles/xml-london <model src="actions/write.xql"/> </action> <collection name="images"> => articles/xml-london/images/ <model src="models/forbidden.xql"/> <action name="POST"> => POST articles/xml-london/images/ <model src="images/upload.xql"/> </action> <item> => articles/xml-london/images/1.png <model src="images/image.xql"/> </item> </collection> </item> </collection>
Oppidum Execution Modela two time engine
eXist-DB implementation
1st step : controller.xql calls gen:process( HTTP Request )
2nd step: URLRewriteFilter executes pipeline
Oppidum Design PatternsTemplating system
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:site="http://oppidoc.com/oppidum/site"> <body> <div id="article"> <site:content/> </div> </body></html>
Sample flowModel output
<Document> <Parag>Hello World</Parag></Document>
View output
<site:view> <site:content> <p>Hello World</p> </site:content></site:view>
Epilogue output
<html xmlns="http://www.w3.org/1999/xhtml"> <body> <div id="article"> <p>Hello World</p> </div> </body></html>
Epilogue templating functionuniversal typeswitch function (cut-and-paste between projects) to includein the epilogue
declare function local:render( $cmd as element(), $source as element(), $view as element()* ) as element(){ element { node-name($source) } { ...typeswitch function calling site:branch function for every site:* extension point... }};
application-dependent function defining the extension points
declare function site:branch( $cmd as element(), $source as element(), $view as element()* ) as node()*{ typeswitch($source) case element(site:skin) return site:skin($cmd, $view) case element(site:lang) return site:lang($cmd, $view) case element(site:navigation) return site:navigation($cmd, $view) case element(site:error) return site:error($cmd, $view) case element(site:login) return site:login($cmd) ... (: default implicitly manages other modules :) default return $view/*[local-name(.) = local-name($source)]/(*|text())};
More design patternsSkinning applications
declarative way to keep the association between CSS and JS files and applicationpages into a skin.xml resource inside the database
Error and message management (Flash a-la Ruby on Rails)
Data mapping
maintaining a relation between URL input space hierarchy and database collectionshierarchy
Form-based access control
Development life cycle (mode="dev|test|prdo" attribute)
Application : FocusNewsletter editor
editorial tool chain for publishing a 4 pages newsletter (3000 printed copies)
Application : AllianceWeb site of the Association Alliance
form editor for participant registration with tool chain to publish badges and list ofparticipants
Application : UAPWeb site of the Union des Artisans du Patrimoine de Belgique
moderated classified ads service for the craftmen member of the association
Application : PSEdatabase of startup companies member of the Science Park at EPFL
multilingual content and search engine (Apache Lucene)
generation of personalized recommendations to improve company pages
JSON export towards an internal advertising TV screen network
ConclusionEffective and efficient XML full stack
implicit “model driven” approach with clear division of work for developers
user generated content with AXEL and AXEL-FORMS (article XML Prague)
backend development with eXist-DB and Oppidum (article XML London)
Open source (available on Github)
Opened issues to go beyond "Small Data"
code portability
abstraction layer for cross-database execution environments ?
see EXPath Webapp framework ? XProc ? RESTXQ ?
failover and load balancing