linked data registry

A CouchDB powered registry for linked data.

• documents are served as JSON-LD or JSON interpreded as JSON-LD and using the semantic of schema.org and hydra (but favoring schema.org/Action over hydra when possible)
• compatible with linked data fragments (triple pattern fragment)

A client is available here.

Registry API

GET /

Return the JSON-LD context used by the registry.

GET /about

Return a JSON-LD document describing the registry and its potential actions using schema.org.

PUT /users/{username}

Register an user. A user has to be a Person.

request body:

{
  "@context": "https://dcat.io",
  "@id": "users/{username}"
  "@type": "Person",
  "password": "secret"
  "name": "John Markup",
  "email": "mailto:[email protected]",
  ...
}

response body:

{
  "@context": "https://dcat.io",
  "@type": "RegisterAction",
  "actionStatus": "CompletedActionStatus",
  "agent": "users/{username}",
  "object": ""
}

Note: relative URLs are relative to a @base of https://dcat.io specified in the context.

DELETE /users/{username}

Unregister an user.

required header:

• Authorization

response body:

{
  "@context": "https://dcat.io",
  "@type": "UnRegisterAction",
  "actionStatus": "CompletedActionStatus",
  "agent": {
    "@type": "Person",
    "email": "mailto:[email protected]
  },
  "object": ""
}

GET /users/{username}

Get a user public profile.

PUT /{namespace}

Create a new JSON-LD document of @id {namespace}.

If a version property is specified in the document, the document will be versionned that is each update will require a new version value to be published. When appropriate version number SHOULD follow semantic versionning.

If a version property is not specified, the new document will replace the previous version irreversibly.

required header:

• Authorization

request body:

{
  "@context": "https://dcat.io",
  "@id": "{namespace}",
  ...
}

Note to be valid a document need at least:

• a @context of value https://dcat.io
• an @id

response body:

{
  "@context": "https://dcat.io",
  "@type": "CreateAction",
  "actionStatus": "CompletedActionStatus",
  "agent": "users/{username}",
  "result": "namespace"
}

DELETE /{namespace}{?version}

Delete a document of @id {namespace} and version {version}. If version is omitted all the versions will be deleted.

required header:

• Authorization

response body:

{
  "@context": "https://dcat.io",
  "@type": "DeleteAction",
  "actionStatus": "CompletedActionStatus",
  "agent": "users/john",
  "object": "{namespace}{?version}"
}

GET /{namespace}/{+pathorurl}{?version}

Get a JSON-LD document of @id {namespace} or a node of this document of @id {namespace}/{pathorurl} or {pathorurl}. In the later case, {pathorurl} has to be an absolute URL encoded as an Uniform Resource Identifier (URI) component.

A specific version can be specified using a query string parameter version whose value is properly encoded as a Uniform Resource Identifier (URI) component. In case the document is versionned following Semantic Versioning, a range (e.g <0.0.1) can be specified as version.

If {?version} is omitted, the latest version of the document is returned.

Depending on the Accept header, documents retrieved from the registry can be served as JSON-LD (expanded, compacted or flattened) or, JSON interpreted as JSON-LD.

GET /maintainers/ls/{namespace}

List the maintainers of a JSON-LD document with @id {namespace}.

response body:

{
  "@context": "https://dcat.io",
  "@id": "{namespace}",
  "accountablePerson": [
    { "@id": "users/john", "@type": "Person", "name": "John Markup", "email": "mailto:[email protected]" },
    ...
  ]
}

POST /maintainers/add/{username}/{namespace}

Add a maintainer of @id users/{username} to the document of @id {namespace}.

required header:

• Authorization

response body:

{
  "@context": "https://dcat.io",
  "@type": "GiveAction",
  "actionStatus": "CompletedActionStatus",
  "agent": "users/{me}",
  "object": "{namespace}",
  "recipient": "users/{username}"
}

POST /maintainers/rm/{username}/{namespace}

Remove a maintainer of @id users/{username} to the document of @id {namespace}.

required header:

• Authorization

response body:

{
  "@context": "https://dcat.io",
  "@type": "TakeAction",
  "actionStatus": "CompletedActionStatus",
  "agent": "users/{me}",
  "object": "{namespace}",
  "recipient": "users/{username}"
}

Raw data storage API

PUT /r/{sha1}

Publish a resource whose SHA-1 message digest (encoded in hex) is {sha1}.

required headers:

• Authorization
• Content-MD5
• Content-Type
• Content-Length
• Encoding (if any)

response body:

{
  "@context": "https://dcat.io",
  "@type": "CreateAction",
  "actionStatus": "CompletedActionStatus",
  "agent": "users/{username}",
  "result": "r/{sha1}"
}

GET /r/{sha1}

Download raw data.

Search API

GET /search/{?keywords}

Search JSON-LD documents by keywords.

Tests

You need couchdb running with an admin defined in env.sh (COUCH_ADMIN_USER and COUCH_ADMIN_PASS) (see env.sh)

couchdb
source env.sh
npm run init
npm run push
npm start
npm test

License

Apache 2.0.