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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.

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();