RDF and SPARQL for PHP Developers (at New York Semantic Web Meetup)

RDF and SPARQL for PHP Developers – NY Semantic Web Meetup - May 21, 2009

RDF and SPARQL for PHP Developers

Benjamin Nowackbnode.org / semsol.com


(1) How can PHP developers benefit from the emerging Semantic Web (technologies)?

(2) How can Semantic Web projects benefit from PHP (developers)?

Two Perspectives


● Templating● Request handlers● Controllers● Framework extensions● Glue code● Prototyping

Scripting Languages


● talk with designers and UX teams● understand data models● talk with (or are) back-end

developers● know agency processes● are efficient and cost-effective

PHP/Ruby/... Developers


Scripting language developers have strong and multidisciplinary front-end skills that lack in the

current SemWeb landscape!


● demand will grow, good investment● more interesting, possibly better

paid projects● improved productivity● more (usable) semantic web apps● reduced time to market

Win-Win


But there is more to the Semantic Web than „just“ direct business

opportunities...


(1) A Web of machine-processable data

(2) A collection of powerful technologies

Two Other SemWeb Perspectives


● Templating/UI: back-end-dependent● Request handlers: custom code and APIs● Controllers: local, fixed models only● Framework extensions: no standards● Glue code: many one-off conversions● Prototypes: schema changes are painful

Technical Issues


Semantic Web technologies address these technical limitations and

related productivity issues.


● a simple, unifying data model (RDF)● standardized data exchange formats● lossless data portability● a powerful, simple data API (SPARQL)● re-mixable schemas (RDFS/OWL)● automated data processing

SemWeb for Web Development


● Templating/UI: back-end independence● Request handlers: reusable code / APIs● Controllers: distributed models● Framework extensions: standards, reuse● Glue code: less conversion code● Prototypes: less painful schema changes

Technical Opportunities


However...


The ROI has to justify the initial friction loss!


● My projects integrate data from the Web● (Semantic) web standards and openness

matter to me and/or my clients● I often work with non-stable schemas ● I can afford betting on an evolving

technology stack

When SemWeb Tech (or not)?


● There is almost no developer-oriented learning material

● Some things work differently in RDF (validation, data quality, API control, ...)

● Identifying and getting used to needed specs and vocabularies takes time

● All toolkits have non-standard extensions

Re Friction Loss


● something light-weight and optimized for PHP environments (and mindsets)

● tools that are easy to combine with existing software

● support for Web 2.0 data formats, too (microformats, RSS2, Atom, JSON)

ARC RDF Classes: Motivation


● RAP (RDF toolkit)● pOWL (CMS, app framework)● ARC (RDF toolkit)● OntoWiki / Erfurt (CMS, API)● Drupal (soon w/ RDF in core)● Trice (CMS, app framework)

Pure-PHP RDF Software


● Redland (RDF toolkit w/ PHP bindings)● Semantic MediaWiki (PHP-based)● Talis platform (has lots of PHP tools)● Virtuoso (PHP interpreter built in)● paget (Linked Data publishing)● Loomp (Semantic publishing)

More PHP(ish) RDF Software


● A pick-what-you-need RDF toolkit● HTTP reading/posting● Parsing (RDF formats, Atom, RSS, MFs)● Serializing (XML, JSON, Turtle)● Storage & Querying (local or remote)● SPARQL Scripting

ARC


● A basic app framework on top of ARC● Working with RDF stores made easy● Path-based request handlers● Forms with automatic RDF generation● Sessions (OpenID or local user:pass)● Themes (per request handler)

Trice


Software requirements:ARC: Web server, PHP, MySQL (storage)Trice: ARC, mod_rewrite, .htaccess

Setup:ARC: uploadTrice: sys.php / upload / file cache /

first request creates RDF store(s)and admin account

ARC / Trice


Examples & Demos● Accelerated prototyping (Data First)● Less painful schema changes (RDF)● Reusable template sections (URIs)● The page is a (standardized) API (RDFa)● Less custom glue code (RDF formats)● A powerful API for free (SPARQL)




Examples & Demos (ctd.)● Lossless Backup/Deploy (UghRIs!)● Simple remote data integration (LOD)● Remote model access (LOD + SPARQL)● Increasing data value (RDFa <=> LOAD)● Inference scripts (Sparqlets)● Putting it all together (Paggr/ConfX)






Some Lessons Learned (the hard way)


• Start small.


• Focus on the use cases at hand.(The „potential“ ones will come early enough.)


• Partition data when possible.


• Resist the „I could automate this even further, right now“ reflex.


• Respect the core standards, but expect the need for custom solutions here and there (and let the community know).


• Don't pick more from the SemWeb Menu than you can consume.



● http://arc.semsol.org/● http://trice.semsol.org/ (soon)● http://semsol.com/● http://bnode.org/

Thank You

Education

RDF and SPARQL for PHP Developers (at New York Semantic Web Meetup)