Aligning
Web Services
with the
Semantic Web
to Create a
Global Read-Write
Graph of Data
Markus Lanthaler
Graz University of Technology

Web services are increasingly popular

Twitter Facebook Google
15 billion 5 billion 5 billion
per day per day per day

Semantic Web is still in its infancy

Semaphobia!?

Lightweight semantic annotations
start to gain acceptance

Increasing interest in the relationship of
RESTful services and Linked Data

Increasing interest in the relationship of
RESTful services and Linked Data

© Nesster
Most previous efforts assume
RPC-style. REST is different.

simplicity
son

{
"id": 556410,
"first_name": "Markus",
"last_name": "Lanthaler",
"gender": "male",
"knows": [
{ "id": 586807, "name": "Christian Gütl" },
{ "id": 790980, "name": "John Doe" } ]
}

{
"id": 556410,
"first_name": "Markus",
"last_name": "Lanthaler",
"gender": "male",
"knows": [
{ "id": 586807, "name": "Christian Gütl" },
{ "id": 790980, "name": "John Doe" } ]
}
"type": "object",
"model": "[foaf:Person]",
"properties": {
"id": {
"type": "number", "model": "[ex:id]" },
"first_name": {
"type": "string", "model": "[foaf:firstName]" },
"last_name": {
"type": "string", "model": "[foaf:surname]" },
...

{
"id": 556410,
"first_name": "Markus",
"last_name": "Lanthaler",
"gender": "male",
"knows": [
{ "id": 586807, "name": "Christian Gütl" },
{ "id": 790980, "name": "John Doe" } ]
}
"type": "object",
"model": "[foaf:Person]",
"properties": {
"id": {
"type": "number", "model": "[ex:id]" },
"first_name": {
"type": "string", "model": "[foaf:firstName]" },
"last_name": {
"type": "string", "model": "[foaf:surname]" },
...

{
"id": 556410,
"first_name": "Markus",
"last_name": "Lanthaler",
"gender": "male",
"knows": [
{ "id": 586807, "name": "Christian Gütl" },
{ "id": 790980, "name": "John Doe" } ]
}
"type": "object",
"model": "[foaf:Person]",
"properties": {
"id": {
"type": "number", "model": "[ex:id]" },
"first_name": {
"type": "string", "model": "[foaf:firstName]" },
"last_name": {
"type": "string", "model": "[foaf:surname]" },
...

{
"id": 556410,
"first_name": "Markus",
"last_name": "Lanthaler",
"gender": "male",
"knows": [
{ "id": 586807, "name": "Christian Gütl" },
{ "id": 790980, "name": "John Doe" } ]
}
"/user/{id}": {
"mediaType": "application/json",
"seredasjDescription": "#",
"variables": {
"id": {
"binding": "#properties/knows/id"
} },
"requestDescription": "#"
}
}

{
"id": 556410,
"first_name": "Markus",
"last_name": "Lanthaler",
"gender": "male",
"knows": [
{ "id": 586807, "name": "Christian Gütl" },
{ "id": 790980, "name": "John Doe" } ]
}
"links": {
"/user/search{?query}": {
"mediaType": "application/json",
"seredasjDescription": "personlist.json",
"semantics": {
"[iana:relation]": "[iana:search]" },
"variables": {
"query": { "model": "[foaf:name]" }
}
},

{
"id": 556410,
"first_name": "Markus",
"last_name": "Lanthaler",
"gender": "male",
"knows": [
{ "id": 586807, "name": "Christian Gütl" },
{ "id": 790980, "name": "John Doe" } ]
}

Two Algorithms

1 select ← createSelect(query)
2 bindings ← tripleStore.execute(select)
3
4 for each binding in bindings do
5 deleteData ← createDeleteData(query, binding)
6 operations.add(deleteData)
7 insertData ← insertDeleteData(query, binding)
8 operations.add(insertData)
9 end for
10
11 operations.sort()
12 translateDataOperations(operations)

1 do
2 requests ← retrievePotentialRequests(triples)
3 progress ← false
4 while requests.hasNext() = true do
5 request ← requests.next()
6 request.setData(triples)
7 request.setData(tripleStore)
8 if isValid(request) = true then
9 if request.submit() = success then
10 resp ← request.parseResponse()
11 triples.update(resp.getTriples())
12 tripleStore.update(resp.getTriples())
13 requests.remove(request)
14 progress ← true
15 end if
16 end if
17 end while
18 while progress = true
19 if triples.empty() = true then
20 success()
21 else
22 error(triples)
23 end if

Publication Management Service

/author/{id} /publication/{id}
foaf:Person foaf:Document
id ex:persId id ex:pubId
name foaf:givenName X title dc:title X
lastname foaf:familyName X authors[] dc:creator X
address v:adr id ex:persId X
city v:locality name foaf:name
country v:country-name

1 INSERT DATA {
2 _:public1 a foaf:Document ;
3 dc:title "My first paper" ;
4 dc:creator _:author1 ;
5 dc:creator auth:cg789 .
6 _:author1 a foaf:Person ;
7 foaf:givenName "Markus" ;
8 foaf:familyName "Lanthaler" ;
9 v:adr _:addr1 .
10 _:addr1 v:country-name "Italy" .
11 }
POST /publication/ POST /author/
{ "title": "My first paper",
"authors": [
{ "id": "cg789" }
]
}
201 Created
Location: /publication/p489/

1 INSERT DATA {
2 _:public1 a foaf:Document ;
3 pub:p489 dc:title "My first paper" ;
4 dc:creator _:author1 ;
5 dc:creator auth:cg789 .
6 _:author1 a foaf:Person ;
7 auth:ml98 foaf:givenName "Markus" ;
8 foaf:familyName "Lanthaler" ;
9 v:adr _:addr1 .
10 _:addr1 v:country-name "Italy" .
11 }
POST /publication/ POST /author/
{ "title": "My first paper", { "name": "Markus",
"authors": [ "lastname": "Lanthaler",
{ "id": "cg789" } "address": {
] "country": "Italy"
} } }
201 Created 201 Created
Location: /publication/p489/ Location: /author/ml98

1 INSERT DATA {
2 _:public1 a foaf:Document ;
3 pub:p489 dc:title "My first paper" ;
4 dc:creator auth:ml98 ;
5 dc:creator auth:cg789 .
6 _:author1 a foaf:Person ;
7 auth:ml98 foaf:givenName "Markus" ;
8 foaf:familyName "Lanthaler" ;
9 v:adr _:addr1 .
10 _:addr1 v:country-name "Italy" .
11 }
PUT /publication/p489
{ "title": "My first paper",
"authors": [
{ "id": "cg789" },
{ "id“: "ml98" }
]
}
200 OK

do it on-the-fly

Thank You
© 2011, Markus Lanthaler. Some Rights Reserved.
http://creativecommons.org/licenses/by-nc-sa/3.0/

Questions?
Markus Lanthaler @MarkusLanthaler
Markus.Lanthaler@student.TUGraz.at http://www.slideshare.net/lanthaler

Image Credits
(1) http://galleries.www.frut.lv/en/5432/959
(3) Adapted from “Two Billion is Cool,” M. Thomson. Available:
http://corp.klout.com/blog/2011/07/two-billion-is-cool/
(5) http://en.wikipedia.org/wiki/The_Scream
(9) http://www.flickr.com/photos/nesster/3168425434/