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Semantic Data Provider

Installation​

npm install @semapps/semantic-data-provider

Usage​

import { Admin } from 'react-admin';
import { dataProvider, httpClient } from '@semapps/semantic-data-provider';

const App = () => (
  <Admin
    dataProvider={dataProvider({
      httpClient,
      dataServers: { ... },
      resources: { ... },
      ontologies: { ... },
      jsonContext: 'http://localhost:3000/context.json',
      returnFailedResources: false
    })}
  >
    <Resource name="Project" ... />
    <Resource name="Organization" ... />
  </Admin>
);

The semantic data provider rely on two important configuration:

  • The Data Servers, which describes the servers to which we want to connect and what they contain.
  • The Data Model, which describes how we want the data to be displayed in React-Admin.

Settings​

httpClient​

HTTP client used to fetch data. Same type as the fetchJson utility of React-Admin.

We recommend to use the httpClient exported from the @semapps/semantic-data-provider package.

dataServers​

See the Data servers page.

resources​

See the Data model page.

ontologies​

List of ontologies used to format or select SPARQL data. Format:

const ontologies = [
  {
    prefix: 'rdf',
    url: 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'
  },
  {
    prefix: 'ldp',
    url: 'http://www.w3.org/ns/ldp#'
  }
];

jsonContext​

All SPARQL results returned will be framed with this context.

If it is not set, the ontologies set above will be used.

returnFailedResources​

If true, the getMany method will not fail completely if one resource is missing.

Missing resources will be returned with their id and _error: true.

Filters​

When using React-Admin filters, in the List components or the ReferenceArrayInput, there are special keywords that you can use:

_predicates​

Return only the given predicates instead of the full resource.

For example, { _predicates: ['foaf:name']} will return only the name of a list of users.

Note: The @type is always returned because it is needed by React-Admin.

_servers​

Select the data servers that you want to query, bypassing the config in the data model.

You can use the server keys or special keywords.

blankNodes​

Choose the blank nodes you want to dereference, bypassing the config in the data model or the VOID endpoint.

For example, { blankNodes: [] } will not dereference any blank nodes for the given resources.

This is useful if you don't need the values of the blank nodes and want to increase performances.

q​

Do a full-text search on the resources.

For example, { q: "sem" } will return all resources with the characters "sem" in string-types values.

sparqlWhere​

Allow to make advanced search by providing a SPARQL.js-formatted array that will be appended to the WHERE query.

Here's an example to fetch ActivityStreams events after a given date:

{
  sparqlWhere: [
    {
      type: 'bgp',
      triples: [
        {
          subject: { termType: 'Variable', value: 's1' },
          predicate: { termType: 'NameNode', value: 'https://www.w3.org/ns/activitystreams#startTime' },
          object: { termType: 'Variable', value: 'startTime' }
        }
      ]
    },
    {
      type: 'filter',
      expression: {
        type: 'operation',
        operator: '>',
        args: [
          {
            termType: 'Variable',
            value: 'startTime'
          },
          {
            termType: 'Literal',
            datatype: {
              termType: 'NamedNode',
              value: 'http://www.w3.org/2001/XMLSchema#dateTime'
            },
            value: '2022-11-17T10:20:13+05:30'
          }
        ]
      }
    }
  ];
}

Note: In the above example, the variable s1 is the URI of a LDP resource.

Hooks​

useContainers​

Returns a list of containers linked with a given resource.

const containers = useContainers(resourceId, serverKeys);

Parameters​

PropertyTypeDefaultDescription
resourceIdStringrequiredReact-Admin resource ID
serverKeysArray or String"@all"The servers where the containers are

Return value​

Array of containers URIs.

useCreateContainer​

Get the URI of the container where to create a new resource.

const createContainerUri = useCreateContainer(resourceId);

Parameters​

PropertyTypeDefaultDescription
resourceIdStringrequiredReact-Admin resource ID

Return value​

URI of the container where to create a new resource.

useCreateContainerUri​

Get the URI of the container where to create a new resource.

const getContainerUri = useCreateContainer();
const createContainerUri = getContainerUri(resourceId);

Return value​

Function to get the URI of the container where to create a new resource

PropertyTypeDefaultDescription
resourceIdStringrequiredReact-Admin resource ID

useDataModel​

Get the data model config of the given resource, including data fetched through VoID endpoints.

const dataModel = useDataModel(resourceId);

Parameters​

PropertyTypeDefaultDescription
resourceIdStringrequiredReact-Admin resource ID

Return value​

The data model config of the given resource.

useDataModels​

Get the data model config of all the resources, including data fetched through VoID endpoints.

const dataModel = useDataModels();

useDataServers​

Get the data servers config, including data fetched through VoID endpoints.

const dataServers = useDataServers();