Sorry, let me sum up the previous messages :
1) I wanted to export a named graph from tdb to ntriples
2) Andy advised to modify s-get, which I did
3) when modifying s-get, I noticed there were 2 wrong content-types :
application/json & application/n-quads ; both give rdf-xml output
4) Andy suggested it came from s-get settings
5) I showed that commenting the settings in s-get have no effect AND
that the problem is the same with curl.
6) my purpose is also to understand how all this stuff works!
Le 31/01/2019 à 14:22, Martynas Jusevičius a écrit :
Vincent,
can you start by explaining what you are trying to do and why, rather
describing how you're doing it?
On Thu, Jan 31, 2019 at 2:20 PM vincent ventresque
<vincent.ventres...@ens-lyon.fr> wrote:
Sorry, I should have explained more clearly : the previous messages
where about default settings in s-get, and when creating a new function
to handle --output option, I noticed there was a wrong content-type in
s-get for plain json (see my s-get file here :
https://sourceforge.net/projects/ffl-misc/files/fuseki_scripts_custom-ruby/s-get/download).
My purpose was to demonstrate that the problem isn't linked to s-get,
since it's the same with curl. Besides, I noticed the same problem with
n-quads.
curl --header 'Accept: application/n-quads'
'http://localhost:3030/test_tdb2?graph=http://test'
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";
xmlns:j.0="http://example.org/"; >
<rdf:Description rdf:about="http://example.org/titi";>
<j.0:tata>coucou</j.0:tata>
</rdf:Description>
</rdf:RDF>
Le 31/01/2019 à 14:12, ajs6f a écrit :
I'm not sure what you expect to get back from Fuseki with an "application/json"
mimetype? There is no W3C-spec plain-JSON RDF serialization that I know of. I suppose
there's the old Tallis idea:
https://jena.apache.org/documentation/io/rdf-json.html
but I can't imagine that's what you're looking for.
ajs6f
On Jan 31, 2019, at 8:09 AM, vincent ventresque
<vincent.ventres...@ens-lyon.fr> wrote:
It seems that the problem is completely independent from s-get (see these
results with curl below). So I think there's a default setting somewhere in
Fuseki itself.
#~~~~~~~ --header 'Accept: application/json' ~~~~~~~~~~~~~~~~~~~~~
:~/Documents/fuseki/bin$ curl --header 'Accept: application/json'
'http://localhost:3030/test_tdb2?graph=http://test'
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";
xmlns:j.0="http://example.org/"; >
<rdf:Description rdf:about="http://example.org/titi";>
<j.0:tata>coucou</j.0:tata>
</rdf:Description>
</rdf:RDF>
#~~~~~~~ --header 'Accept: application/rdf+json' ~~~~~~~~~~~~~~~~~~~~~~
:~/Documents/fuseki/bin$ curl --header 'Accept: application/rdf+json'
'http://localhost:3030/test_tdb2?graph=http://test'
{
"http://example.org/titi"; : {
"http://example.org/tata"; : [ {
"type" : "literal" ,
"value" : "coucou"
}
]
}
}
Le 31/01/2019 à 12:58, vincent ventresque a écrit :
Thanks for your quick reply!
$mtAppJSON isn't used.
I think my previous msg wasn't clear : I meant raw json and not json-ld (my
code works now for both, and I use $mtAppJSON ; but I had to replace
'application/json' with 'application/rdf+json' in order to get json instead of
XML ; see the file here
https://sourceforge.net/projects/ffl-misc/files/fuseki_scripts_custom-ruby/s-get/download)
The settings are: ...
I made a little test : comment these lines and the "names" part, and you'll get
XML!
Le 31/01/2019 à 12:48, Andy Seaborne a écrit :
On 31/01/2019 11:26, vincent ventresque wrote:
Hello,
I found the origin of the problem for json : the $mtAppJSON had the value
'application/json'
$mtAppJSON isn't used.
"application/rdf+json"
isn't JSON-LD (it's the old Talis format).
There is:
$mtJSONLD = 'application/ld+json'
it has to be replaced with
'application/rdf+json'
I've updated the file here :
https://sourceforge.net/projects/ffl-misc/files/fuseki_scripts_custom-ruby/s-get/download
Maybe I'm going to submit a pull request as Andy suggested, but I'd like to
understand why 'application/json' returns xml. Besides, it's the same thing for
nquads : I tried to replace
$mtNQuads = 'application/n-quads'
with
$mtNQuads = 'application/x-trig'
but still have xml...
The settings are:
# Default for GET
# At least allow anything (and hope!)
$accept_rdf="#{$mtTurtle} , #{$mtNTriples};q=0.9 , #{$mtRDF};q=0.8 ,
#{$mtJSONLD};q=0.5"
# Datasets
$accept_ds="#{$mtTrig} , #{$mtNQuads};q=0.9 , #{$mtJSONLD};q=0.5"
# For SPARQL query
$accept_results="#{$mtSparqlResultsJ} , #{$mtSparqlResultsX};q=0.9 ,
#{$accept_rdf}"
# Accept any in case of trouble.
$accept_rdf="#{$accept_rdf} , */*;q=0.1"
$accept_results="#{$accept_results} , */*;q=0.1"
Is there a kind of default setting somewhere (if content-type isn't recognized
in Fuseki, the response is xml) ?
Yes.
RDF/XML for graphs, N-Quads for datasets.
Run Fuseki/full with "-v" and it should print the content negotiation details.
Andy
Thanks in advance
VV
Ok, maybe I'm going to submit a pull request, but I'd
Le 29/01/2019 à 17:11, vincent ventresque a écrit :
Hi Andy,
Thanks again for your idea to modify the s-get script, it helped me understand
ruby utilities and http requests (I often use the ruby scripts but never really
looked inside).
Don't know how to submit a pull request, and I'm not a ruby expert! Therefore
I've put a small test file here :
https://sourceforge.net/projects/ffl-misc/files/fuseki_scripts_custom-ruby/s-get/download
-- added "--output" in options + created a new function (set_output_format)
-- it works for ntriples, xml, Json-LD,
-- doesn't work for json (returns xml...)
N.B. : in this test file, I've removed large parts of the original code in
order to improve readability
Le 28/01/2019 à 15:28, Vincent Ventresque a écrit :
Hi Andy,
Many thanks for these ideas, I'm going to try the curl & riot solutions.
Modify the s-get script to handle --output and set the "Accept:" header then
please submit a pull request for the changes
I had made an attempt to modify the s-get script in the same way as for s-query
but it didn't work : if I have a moment I'll try to understand how the options
are handled.
Le 28/01/2019 à 14:19, Andy Seaborne a écrit :
On 28/01/2019 11:04, Vincent Ventresque wrote:
Hello,
I want to export a named graph which is stored in a TDB dataset, and I want to
store the output in several files (for the named graph contains +/- 9.5 M
triples).
My idea is to use "split" command in order to cut the output of the export into pieces.
However, this solution with "split" requires ntriples or nquads (one triple per line, so
that the files are not cut in the middle of an assertion ; besides, it's also more practical to
have a triple per line if I want to transform the data with perl or sed).
I found a solution with s-query but had to edit the ruby s-query script to get
ntriples (see below).
There are other possible solutions for an export via command-line utilities : "s-get" and
"tdbdump". If I understand well, "tdbdump" gives nquads as output, but one can't export only a part
of the data, everything is exported at once. The "s-get" solution allows to select a named graph in the
dataset, but I couldn't change the output format.
Are there better solutions to get an export in several files?
Ways I can think of:
1/ Modify the s-get script to handle --output and set the "Accept:" header then
please submit a pull request for the changes.
2/ Use curl
curl --header 'Accept: application/n-triples' \
'http://localhost:3030/ds?graph=http://bnf_titres'
3/ Parse the s-get output:
s-get ... | riot --syntax TTL
Andy
Thanks in advance,
VV.
~~~~~~~~~~~ 1) SOLUTION WITH s-query ~~~~~~~~~~~~~~~~~~~~~
1.1) Edit s-query ruby script (add nt)
-- l. 572 : when "json","xml","text","csv","tsv","nt"
-- l. 574 : when :json,:xml,:text,:csv,:tsv,:nt
-- l. 515 : opts.on('--output=TYPE', [:json,:xml,:text,:csv,:tsv,:nt],
-- l. 519 : opts.on('--accept=TYPE', [:json,:xml,:text,:csv,:tsv,:nt],
1.2) Command
/my/path/to/fuseki/bin/s-query --service=http://localhost:3030/BnF_text_v2/ "construct {
?s ?p ?o } where { graph <http://bnf_titres> { ?s ?p ?o }}" --output=nt | split -l
500000 - --additional-suffix=.nt BnfTextTitres-
~~~~~~~~~~~ 2) SOLUTION WITH tdbdump (nquads but no named graph)
~~~~~~~~~~~~~~~~~~~~~
/my/path/to/jena/bin/tdbdump --loc=/my/path/to/fuseki/run/databases/BnF_text_v2
--graph=http://bnf_titres | split -l 500000 - --additional-suffix=.nt
BnfTextTitres-
=> Unknown argument: graph
~~~~~~~~~~~ 3) SOLUTION WITH s-get (named graph ok, but turtle output)
~~~~~~~~~~~~~~~~~~~~~
/my/path/to/fuseki/bin/s-get http://localhost:3030/BnF_text_v2/data
http://bnf_titres --output=text | split -l 500000 - --additional-suffix=.nt
BnfTextTitres-
=> /my/path/to/fuseki/bin/s-get:364:in `cmd_soh': invalid option: --output=text
(OptionParser::InvalidOption)
from /my/path/to/fuseki/bin/fuseki/bin/s-get:715:in `<main>'
