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

rdf and sparql for php developers (at new york semantic web meetup)

Education

web semantic web standards

semantic web projects

rdf formats

rdf validation

web server

web of machine

web development

php environments