The Joomla! RDF Syndication Demo shows how to off-the-shelf Semantic Web technology to syndicate and browse relevant data from distributed Web resources. The following screen cast includes 4 show cases:
Browse Joomla! content in factet browser
Syndicate Joomla! content from mutiple Joomla! sites then render then in facet browser
Search relevant posts of a Joomla! user (using his email as searching keyword) in a Semantic Web Search Engine (Sindice.com)
Integrate user's personal information from remote RDF-based resources (FOAF file,vcard,html pages with microformat,etc) to user's profile through a web remixing server (Semantic Web Pipes).
Semantic Web is becoming more real, there is increasings number of web services, applications supporting RDF data. Moreover, there are variety of valuable semantic data sources like those of mentioned in LinkingOpenData cloud [1]. However, it normally takes a lot of efforts to implement a web site supporting Semantic Web data. Specially, it is unlikely to take Semantic Wen into account when implementing a small website like CMS, blog, forum due to the complexity and cost of implemetation. Hence, inspiring from RSS syndication which is very popular in any website, we implement this demo to give some showcases of RDF syndication. In order to encourage web developer to expose, integrate, syndicate RDF data, this demo will show the light-weight of exposing and integrating data from Joomla!, a CMS platform, without installing any additional database and triple processing library to their websites.
In this demo, we will adopt Triplify[2] script as a Joomla! component to expose data as RDF/JSON feed which can be crawled by Semantic Search Engine (Sindice, SWSE, SWOOGLE) or syndicated by using scripting language. Similar to RSS feed reader, we customize Exhibit to build RDF/JSON feed reader. This feed reader plays the role ofa facet browser which can be embedded to any HTML page as a widget. This feed reader can read RDF data encoded in Exhibit[3] JSON format from these types of resources:Joomla! exposed RDF data, Semantic Web Pipes andSindice’sSIOC sphere search results.
2Architecture
Our showcases will be implemented in the architecture as figure 1. In this architecture, data from content publishing platform like Wordpress, Drupal, Joomla can be exposed in RDF format and then processed by Search engine like Sindice[4] or remixing server like Semantic Web Pipes[5]. Thus, such RDF data processing like querying, crawling, indexing, reasoning, remixing, etc are done in those remote servers. On the other hand, the small plugins like Triplify or SIOC exporters will reveal semantic structures encoded in relational database and mak their underlying content available in RDF or JSON.
The processed data or exposed RDF data can be reached by RDF syndication script like Javascript in JSON format. This syndication script will be embedded in cross-site syndicating component ofJoomla which plays the role as RDF feed aggregator and reader similar to any RSS’s one. Syndication script has been used in this architecture is Exhibit. It can feed Exhibit JSON data from multiple and distributed resources and represented in a facet browser. These Exhibit JSON data will be loaded to a graph-based database which can be queried by simple graph pattern expressions. Because all data querying and rendering will be done in browser, the cross-sites syndication component is only responsible for configurating data sources and output views, lens in order to have appropriate syndication to users.
Figure 1. Architecture of light-weight RDF syndication with Joomla
3Showcases
Our showcases are hosting at http://swm.deri.org/jsyndication/. This website, called JSyndication, is an example Joomla! site installed our Joomla! syndication component. This component will expose content in this site in RDF and JSON. The exposed content can be viewed in rendered HTML page. Similarly, we installed our component to 2 other sites, then we feed content of these remote sites to JSyndication (Joomla RDF feeds). We also has a page called “Favourite RDF feeds” which feed any RDF data sources in Exhibit JSON format.
User can also add some feed to his profile as personal information by create some Semantic Web Pipes remixing his Foaf file and some other information from other resources. For example, author of a news article, named Tim Berner-Lee, create some Pipes which remix his Foaf file, publications from DBpedia,DBLP,ect then submit these Pipes’ URLs to his profile. Thus, when clicking on an author, we will see the “personal information” link which redirects us to author’s syndicated profile.
Another link we can see when clicking an author is “recent Posts”. This link will forward us to the syndication which feeds all of indexed posts of an author from Sindice. These posts were crawled by Sindice from submitted links from Web sites where the author published his posts.
References
[1] Linking Open Data .http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/ LinkingOpenData
[2]. Triplify http://triplify.org/.
[3] Huynh, D. F., Karger, D. R., and Miller, R. C. 2007. Exhibit: lightweight structured data publishing. In Proceedings of the 16th international Conference on World Wide Web (Banff, Alberta, Canada, May 08 - 12, 2007). WWW '07. ACM, New York, NY, 737-746.
[4] Sindice – The Semantic Web Index. http://www.sindice.com/.
[5]. C. Morbidoni, A. Polleres, G. Tummarello, and D. Le Phuoc. SemanticWeb Pipes. Technical Report, see http://pipes.deri.org/. Nov. 2007.
Have you ever think that "is it possible to categorize and link your Joomla! articles with entities (people, places, organizations, etc.), facts (person ‘x’ works for company ‘y’), and events (person ‘z’ was appointed chairman of company ‘y’ on date ‘x’)?".Yes, theorically, it's possible,but, to have such functionalities, we have to spend a lot of efforts on natural language processing, machine learning and other stuffs. So,practically,not feasible for a small and medium CMS. However, it's still insteresting and worth trying,isn't it? .So,let's try a webservice like Calais[1] which provides such funtionalities through websevice calls.
In Calais Overview site they said that "The Calais web service automatically attaches rich semantic metadata to the content you submit" and such "metadata gives you the ability to build maps (or graphs or networks) linking documents to people to companies to places to products to events to geographies to … whatever. You can use those maps to improve site navigation, provide contextual syndication, tag and organize your content, create structured folksonomies, filter and de-duplicate news feeds or analyze content to see if it contains what you care about. And, you can share those maps with anyone else in the content ecosystem". This sounds very attractive,right? . But don't be too optimistic, it is not perfect yet. Let play arround with their viewer at [2], to find out yourself which kind of extracted data they can give you. Or you can check out [3] to see very useful comments of their usecase. And actually, Wordpress and Drupal already integrated Calais to enable auto-tagging, see the Gallery section of Calais website to interesting examples. Let's come up with an extension or plugin for Joomla, it won't take much effort,but definitely could be a lot of fun with it!!!!
Danh Le Phuoc is a PhD student from Vietnam studying with the Digital Enterprise Research Institute (DERI) in Ireland. DERI is a leading research facility worldwide for the Semantic Web. Danh has a rich technical background with eight years of SW research and has contributed to numerous open source projects, including the Semantic Web Pipes, Integrated Modeling, Simple Widget Markup and Global Sensor Network. Danh is also an experienced Joomla! developer who has created extensions and several Web sites using Joomla!.
Mentor: Nur Aini Rakhmawati is nearing her July graduation from the National Taiwan Universityof Science and Technology in Taipei, Taiwan when she will be awarded a Masters degree in Electronic Engineering. Following her graduation, Aini plans to return to her home in Indonesia. Aini is a GSoC student from 2007 and a contributing member of the Joomla! Development Team. She is working on a Smart Card Web Server and is involved in the N2Women, LinuxChix and Debian Women organizations.
Last year, Joomla has more than 3 million downloads last year. From this fact, consider how many sites are using Joomla! and the volume of Joomla! content produced daily. Then, consider how those contents are data islands without any ability to automatically link this content to other sites or to be able to re-use the data as mashups. Actually, we
can already re-use data with RSS feeds, but RSS is too simple to express the potentially implicit links among them.
Hence, inspriring from Triplify ideas[17], we propose the approach called Linked Data [1] which enable users to navigate from a data item related data items through RDF [2] Links. RDF Link is actually a semantic statement about this data item and can be published by URI, for example, “user id lpdanh has the name Danh Le Phuoc who has homepage with url and has the article http://example.com/articleid=100 with the title ‘Semantic Links for Joomla’ and see also the extended version at article http://anotherblogsite.net/blogid=200, etc.”
.So,let's try a webservice like 
. But don't be too optimistic, it is not perfect yet. Let play arround with their viewer at 
Mentor: 
Mentor: