@telicent-oss/catalogservice

Monorepo Location: ./packages/CatalogService

Utility classes for managing RDF data for DCAT3-compliant data catalogs via SPARQL.

Plus a ApiFactory that uses the above to create a convenience api object for Catalog web app (may move out of this package).

Background

@telicent-oss/rdfservice (./packages/RdfService) package was created to give separation between UI code and SPARQL query logic. This package, extends upon @telicent-oss/rdfservice to give the the data catalog functionality.

Install

yarn install @telicent-oss/catalogservice

Usage

DCAT classes

A simple example for data catalogs:

:warning: Temporarily broken

import {
  CatalogService,
  DCATCatalog,
} from "@company-oss/catalogservice";

// Initialize the CatalogService
const catalogService = await CatalogService.createAsync({
  writeEnabled: true,
  triplestoreUri: "http://localhost:3030",
  dataset: "dataset",
});

// Create Catalog
const catalog1 = await DCATCatalog.createAsync(
  catalogService,
  "http://mysche.ma/data/catalog1",
  "Catalog",
  "2023-01-01"
);

:warning: Temporarily broken

/*

Given we want to create this structure:
.
├── catalog1/
│   └── catalog1_1/
│       ├── DataService1_1_1
│       ├── DataSet1_1_1
│       └── DataSet1_1_2
└── catalog2/
    └── DataSet_2_1
*/
import {
  CatalogService,
  DCATCatalog,
  DCATDataset,
  DCATDataService,
} from "@company-oss/catalogservice";

// Initialize the CatalogService
const catalogService = await CatalogService.createAsync({
  writeEnabled: true,
  triplestoreUri: "http://localhost:3030/"
  dataset: "dataset"
});
const DC3 = 'http://mysche.ma/data/'
// Create Catalog 1
const catalog1 = await DCATCatalog.createAsync(
  catalogService,
  `${DC3}catalog1`,
  "Catalog 1",
  "2023-01-01"
);

// Create nested Catalog 1_1
const catalog1_1 = await DCATCatalog.createAsync(
  catalogService,
  `${DC3}catalog1_1`,
  "Catalog 1_1",
  "2023-02-01"
);
catalog1.addSubCatalog(catalog1_1);

// Add DataService to Catalog1_1
const dataService1_1_1 = await DCATDataService.createAsync(
  catalogService,
  `${DC3}catalog1_1/DataService1_1_1`,
  "Data Service 1_1_1"
);
catalog1_1.addOwnedResource(dataService1_1_1);

// Add DataSets to Catalog1_1
const dataSet1_1_1 = await DCATDataset.createAsync(
  catalogService,
  `${DC3}catalog1_1/DataSet1_1_1`,
  "Data Set 1_1_1",
  "2023-03-01",
  catalog1_1
);
const dataSet1_1_2 = await DCATDataset.createAsync(
  catalogService,
  `${DC3}catalog1_1/DataSet1_1_2`,
  "Data Set 1_1_2",
  "2023-03-02",
  catalog1_1
);

// Create Catalog 2
const catalog2 = await DCATCatalog.createAsync(
  catalogService,
  `${DC3}catalog2`,
  "Catalog 2",
  "2023-04-01"
);

// Add DataSet to Catalog2
const dataSet2_1 = await DCATDataset.createAsync(
  catalogService,
  `${DC3}catalog2/DataSet2_1`,
  "Data Set 2_1",
  "2023-05-01",
  catalog2
);

Using ApiFactory for the Data Catalog UI

You can find a working example in https://github.com/Telicent-oss/catalog

• setup
• usage

export const catalogService = await CatalogService.createAsync({
  writeEnabled: true,
  triplestoreUri: `${config.env.TRIPLE_STORE_URL}/`,
  dataset: "catalog",
});
const api = await apiFactory(catalogService);

const Page = ({ searchTerm, dataResourceFilters, set }) => {
  const catalog = useQuery({
    queryKey: ['catalog', dataResourceFilters],
    queryFn: () => api.catalog({ dataResourceFilters }),
  });
  const search = useQuery({
    queryKey: ['search', searchTerm],
    queryFn: () => api.search({ searchTerm })
  });
  return (
    <>
      <SearchInput
        onSearch={searchTerm => set({ searchTerm })}
      />
      <DataResourceFilters
        data={catalog.data}
        onSelect={val => set({ dataResourceFilters: val })}
      />
    <>
  );
}

Development

Build

git clone https://github.com/Telicent-oss/rdf-libraries
cd catalog
yarn install
cd /packages/CatalogService
# make changes
npx nx affected:build

Develop locally

Run the provided triple store

yarn start:triple-store-for-local-dev-and-tests

Or alternatively run your own.

Related Links

• Catalog - ReactJS web app that uses this package
• RdfService - sibling package; This package extends some of its RDF utility classes

Definitions

• DCAT3: Data Catalog Vocabulary, version 3, a W3C standard for representing data catalogs.
• SPARQL: SPARQL Protocol and RDF Query Language, used for querying RDF data.
• Triple Store: A type of database optimized for storing and retrieving RDF triples.

API

For detailed API usage examples, refer to CatalogService.test.ts (and other tests)