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Triple Store API

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Jerome Fuselier edited this page Mar 14, 2017 · 1 revision

The ERMR triple store API acts as a mediator between clients and the internal triple store we are using. It interprets the requests of the client and forward a request in the correct format for the triple store.

When you have succesfully deployed ERMR on a host, the CDMI web service is accessible at http://host/api/triple.

List repositories

Synopsys

To list existing repositories, the following request shall be performed:

GET <root URI>/api/triple

where:

  • <root URI> is the path to the registry.

Response Message Body

The response message contains a JSON list of repositories informations (to be refined).

Response Status

HTTP Status Description
200 OK The list is returned

Example

GET a list of repositories:

GET /api/triple HTTP/1.1
Host: 192.168.56.100

Response:
HTTP/1.1 200 Ok

[ { "title": "DemoLondon", "writable": true, "id": "DemoLondon" }, 
  { "title": "Test", "writable": true, "id": "Test" } ]

Create a repository

Synopsys

To create a new repository, the following request shall be performed:

PUT <root URI>/api/triple/<NewRepositoryName>

where:

  • <root URI> is the path to the registry.
  • <NewRepositoryName> is the name for the repository to be created.

Response Status

HTTP Status Description
201 Created The new repository was created

Example

PUT to the triple store URI to create a repository:

PUT /api/triple/MyRepository HTTP/1.1
Host: 192.168.56.100

Response:
HTTP/1.1 201 Created

Delete a repository

Synopsys

To delete a repository, the following request shall be performed:

DELETE <root URI>/api/triple/<repositoryName>

where:

  • <root URI> is the path to the registry.
  • <repositoryName> is the name of the repository to be deleted.

Response Status

HTTP Status Description
204 No Content The repository was deleted

Example

DELETE a repository:

Delete /api/triple/MyRepository HTTP/1.1
Host: 192.168.56.100

Response:
HTTP/1.1 204 No Content

Add triples to a repository

Synopsys

The following HTTP PUT/POST requests add triples to a repository. A PUT request empty the repository first while a POST request add triples.

PUT <root URI>/api/triple/<repositoryName>/statements

POST <root URI>/api/triple/<repositoryName>/statements

Where:

  • <root URI> is the path to the registry.
  • <repositoryName> is the name of the repository.

Request Headers

Header Type Description Requirement
Content-Type Header String The content type of the triples Mandatory
“text/plain” for ntriples
“application/rdf+xml” for RDF
“text/turtle” for Turtle

Request Body

The request message body contains the data to be stored.

Response Status

HTTP Status Description
201 Created The triples were added

Example

PUT triples to the repository URI:

PUT /api/triple/MyRepository/statements HTTP/1.1
Host: 192.168.56.100
Content-Type: text/plain

<http://www.pericles.org/models#process1> <http://www.pericles.org/models#name> "Ingest" .
<http://www.pericles.org/models#process1> <http://www.pericles.org/models#description> "Ingest documents in the registry" .
<http://www.pericles.org/models#process1> <http://www.pericles.org/models#identity> "7d4e14c8-1adf-4cfd-b0b8-ede46944b006" .
<http://www.pericles.org/models#process1> <http://www.pericles.org/models#version> "0.1" .

Response:
HTTP/1.1 201 Created

List triples of a repository

Synopsys

To list triples contained in an existing repository, the following request shall be performed:

GET <root URI>/api/triple/<repositoryName>

GET <root URI>/api/triple/<repositoryName>/statements

where:

  • <root URI> is the path to the registry.
  • <repositoryName> is the name of the repository to list.

Request Headers

Header Type Description Requirement
Accept Header String “application/json” Optional
“application/rdf+xml”

Response Message Body

By default the response message contains a JSON list of triples. Specifying “application/rdf+xml” as the Accept header can be used to obtain the result in XML.

Response Status

HTTP Status Description
200 OK The list is returned

Example

GET a list of repository triples:

GET /api/triple/MyRepository HTTP/1.1
Host: 192.168.56.100

Response:
HTTP/1.1 200 Ok

[
    [
        "<http://www.pericles.org/models#process3>",
        "<http://www.pericles.org/models#version>",
        "\"1.0\""
    ],
    [
        "<http://www.pericles.org/models#process3>",
        "<http://www.pericles.org/models#identity>",
        "\"3ecdb028-40ec-453a-b4eb-21ad9234ac5e\""
    ],
    [
        "<http://www.pericles.org/models#process3>",
        "<http://www.pericles.org/models#description>",
        "\"Extract metadata in a document of the registry\""
    ],
    [
        "<http://www.pericles.org/models#process3>",
        "<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>",
        "<http://www.pericles.org/models#process>"
    ],
...
]

Delete all triples of a repository

Synopsys

To delete all triples of a repository, the following request shall be performed:

DELETE <root URI>/api/triple/<repositoryName>/statements

where:

  • <root URI> is the path to the registry.
  • <repositoryName> is the name of the repository that contains triples to be deleted.

Response Status

HTTP Status Description
204 No Content The triples were deleted

Example

DELETE a repository:

Delete /api/triple/MyRepository/statements HTTP/1.1
Host: 192.168.56.100

Response:
HTTP/1.1 204 No Content

Query a repository

Synopsys

To send a SPARQL query to a repository, the following request shall be performed:

GET <root URI>/api/triple/<repositoryName>?query=<SparqlQuery>

where:

  • <root URI> is the path to the registry.
  • <repositoryName> is the name of the repository to query.
  • <SparqlQuery> is a sparql query encoded as a URI.

Request Headers

Header Type Description Requirement
Accept Header String “application/json” Optional
“application/sparql-results+xml”
“application/sparql-results+json”

Response Message Body

By default the response message contains a JSON dictionary (“application/json”):

  • “values stores a list of tuples
  • “name” stores a list of names for the returned tuples

Specifying “application/sparql-results+xml” or “application/sparql-results+json” can be used to obtain these outputs :

Response Status

HTTP Status Description
200 OK The result is returned

Example

GET to evaluate a SPARQL query on a repository:

GET /api/triple/MyRepo?query=select%20?s%20?p%20?o%20%7B?s%20?p%20?o%7D HTTP/1.1
Host: 192.168.56.100

Response:
HTTP/1.1 200 Ok

{
    "values": [
        [
            "<http://www.pericles.org/models#version>",
            "\"1.0\""
        ],
        [
            "<http://www.pericles.org/models#identity>",
            "\"3ecdb028-40ec-453a-b4eb-21ad9234ac5e\""
        ],
        [
            "<http://www.pericles.org/models#name>",
            "\"Convert\""
        ],
...
    ],
    "names": [
        "p",
        "o"
    ]
}

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