Valentin's Blog

Well, at least until the 'Semantic Web Pipes' are ready for prime time: a webservice that allows to query sparql endpoints from within Yahoo Pipes. Look at the example below: It shows a simple pipe that takes a name as input, uses it to query the dblp sparql endpoint and returns the result as web page, JSON and RSS. You can try the pipe here. Surely getting an RSS feed for the publications from dblp could have been achieved without RDF-SPARQL-Pipes, however, we can now access all kinds of SPARQL endpoints and have the entire functionality of Yahoo Pipes at hand to combine it with other (possibly non-SemWeb) content.

Let me quickly explain the pipe: The 'Please enter the name' element defines the 'name' input to the pipe. The 'String Builder' block uses this name to build a sparql query and the 'Item Builder' combines the query and the endpoint URL (http://www4.wiwiss.fu-berlin.de/dblp/sparql, in this case) into an item that will be send to the web service. The web service (that lives at http://soboleo.fzi.de:8080/PipesSparqlr/sparql [1]) takes the query and endpoint URL, sends the query to the endpoint and translates the answer to a simpler JSON format[2]. Any error encountered is simple returned instead of a result - so you are able to see it in the debugger view of Yahoo Pipes.  The last operator, the Regex element, removes anything but characters from the item's title - sadly that's necessary because somewhere along the line the character encodings get mixed up and this is tripping up Yahoo Pipes so badly, that no result is returned as soon as one of the titles contains something like for example a German 'ä' or 'ö'. I'll try to fix this someday. The source code for the webservice (all ~100 lines of it ;) ) is available here - feel free to use it anyway you like. You'll need the JSON library and Java 1.5+ to compile, and some servlet container (I use tomcat 5.5.something) to run it. 

[1]: Feel free to use this webservice but don't count on it staying there forever.
[2]: Just passing through the SPARQL query result XML caused problems with Yahoo Pipes which expects either JSON or RSS.

Labels: Mashup, SemanticWeb, Web

Google Video has a talk about Yahoo Pipes. In general its a nice and gentle introduction to pipes, I found four tidbits of information mainly about the future plans of Pipes very interesting:

• In the new future they plan to allow you to add your own webservices as modules. 
• They are looking into ways to allow you to safely build Pipes on your private, password protected data (such as emails, calendars etc). Although it sounded like this is still quite a bit off.
• Yahoo Pipes is internally build on top of XML; its agnostic to whether its RSS or XML/RDF.  In the beginning they put the focus on RSS to make the tools easier to understand.  Not sure whether this is good news - processing RDF as XML really is neither easy nor powerful (compared to processing it as RDF).
• In general they struggle with the Power vs. Simplicity tradeoff; for example that led them to postpone the release of a database like "join" module for XML files.

Sadly they did not speak about the business case behind Yahoo Pipes, how Yahoo plans to earn money with this service.

Labels: Mashup, SemanticWeb, Web

Very very cool, hadn't heard of it before: a mashup creating wiki system for the enterprise:

QEDWiki is a lightweight mash-up maker written in PHP 5 and hosted on a LAMP, WAMP, or MAMP stack. A mash-up assembler will use QEDWiki to create a personalized, ad hoc Web application or mash-up by assembling a collection of widgets on a page, wiring them together to define the behavior of the mash-up application, and then possibly sharing the mash-up with others. Mash-up enablers provide QEDWiki with a collection of widgets that provide application domain- or information-specific functionality. These widgets are represented within QEDWiki as PHP scripts.

They also have a good demo video (although the speaker is annoying - somebody should tie his hands next time).

I hadn't had time to test it - but the demo looks  amazing.

Labels: Mashup

From O'Reilly Radar:

Yahoo! Pipes was released today with the goal of allowing people to easily mix, match, filter, sort and merge data sources into RSS feeds. These resulting RSS feeds are called Pipes and they allow you to do things like find all of the parks in your city or convert the news to Flickr photos. The product allows you to browse pipes, search for pipes, share pipes, or clone somebody else's pipe.

More:

Yahoo!'s new Pipes service is a milestone in the history of the Internet. It's a service that generalizes the idea of the mashup, providing a drag and drop editor that allows you to connect Internet data sources, process them, and redirect the output. Yahoo! describes it as "an interactive feed aggregator and manipulator" that allows you to "create feeds that are more powerful, useful and relevant." While it's still a bit rough around the edges, it has enormous promise in turning the web into a programmable environment for everyone.

Very cool stuff, but "generalizing the idea of the mashup" - wasn't this the job of the Semantic Web? (yea, a pipe like service on RDF would be much, much, cooler).

Even more here and  here.

Labels: Mashup, SemanticWeb