Custom Connector
Open Data City of Liege
Belgium
The Open Data City of Liege Connector facilitates seamless integration with the Open Data City of Liege API (Explore API v2.1), providing access to all open datasets on the platform. Organized around REST, it acts as a proxy for querying datasets, catalog exports, and dataset records, with structured data responses.
Overview
Integration Overview
This document provides a detailed guide for each integration point, its purpose, configuration, and workflow support using the Open Data City of Liege API Connector.
- getDatasets. Retrieve available datasets from the catalog.
- listExportFormats / exportDatasets / exportCatalogCSV / exportCatalogDCAT. List catalog export formats and export the catalog in a chosen format, CSV, or DCAT.
- getDatasetsFacets. Enumerate facet values for datasets in the catalog.
- getRecords. Query records for a specific dataset.
- listDatasetExportFormats / exportRecords / CSV / Parquet / GPX. List and run per-dataset exports in a chosen format.
- getDataset. Return information, metadata, and endpoints for a dataset.
- getRecordsFacets. Enumerate facet values for records within a dataset.
- getDatasetAttachments. Return all available attachments for a dataset.
- getRecord. Read a single dataset record by identifier.
Documentation
Detailed Integration Documentation
Get Datasets
| Action | getDatasets |
|---|---|
| Purpose | Retrieves a list of available datasets from the catalog. |
| Configuration | Configure the base URL via CONNECTOR_ENV_OPENDATA_LIEGE_API_BASE_URL, with API-key authentication via the apikey query parameter. |
| Parameters | Optional: select; where; order_by; limit (default 10, max 100 — 20000 with group_by); offset; refine; exclude; lang (default fr); timezone; group_by; include_links; include_app_metas. |
| Output | Successful: JSON with total_count and a results array (metadata, fields, links). Failure: 400 / 401 / 429 / 500. |
| Workflow example | Execute getDatasets with limit=5 and offset=0 to display the first five datasets. |
Catalog Exports (formats / export / CSV / DCAT)
| Action | listExportFormats / exportDatasets / exportCatalogCSV / exportCatalogDCAT |
|---|---|
| Purpose | Lists catalog export formats and exports the catalog in a chosen format, CSV (configurable options), or RDF/XML (DCAT). |
| Configuration | Configure the base URL via CONNECTOR_ENV_OPENDATA_LIEGE_API_BASE_URL, with API-key authentication via the apikey query parameter. |
| Parameters | exportDatasets required: format (csv/json/xlsx). CSV optional: delimiter; list_separator; quote_all; with_bom (default true). DCAT required: dcat_ap_format; optional include_exports, use_labels_in_exports. |
| Output | Successful: a JSON list of export links or a file. Failure: 400 / 401 / 429 / 500. |
| Workflow example | Call listExportFormats, then exportCatalogCSV with delimiter=, and with_bom=false. |
Get Datasets Facets
| Action | getDatasetsFacets |
|---|---|
| Purpose | Enumerates facet values for datasets, supporting guided navigation and UI filters. |
| Configuration | Configure the base URL via CONNECTOR_ENV_OPENDATA_LIEGE_API_BASE_URL, with API-key authentication via the apikey query parameter. |
| Parameters | Optional: facet; refine; exclude; where; timezone. |
| Output | Successful: JSON with facet lists (values, count, state). Failure: 400 / 401 / 429 / 500. |
| Workflow example | Execute getDatasetsFacets with facet=publisher to display publishers and dataset counts. |
Records, Dataset Info & Single Record
| Action | getRecords / getDataset / getRecord / getRecordsFacets |
|---|---|
| Purpose | Queries dataset records; returns dataset metadata, fields, and endpoints; reads a single record by ID; and enumerates record-level facets. |
| Configuration | Configure the base URL via CONNECTOR_ENV_OPENDATA_LIEGE_API_BASE_URL, with API-key authentication via the apikey query parameter. |
| Parameters | Required: dataset_id (getRecord also needs record_id; getRecordsFacets takes facet). Optional: select, where, group_by, order_by, limit (max 100 — 20000 with group_by), offset, refine, exclude, lang, timezone, include_links, include_app_metas. |
| Output | Successful: JSON with total_count + results, dataset metadata, a single record, or facet values. Failure: 400 / 401 / 429 / 500. |
| Workflow example | Execute getRecords with dataset_id=geonames-all-cities-with-a-population-1000 and limit=2, then getRecord for detail. |
Dataset Exports (formats / CSV / Parquet / GPX) & Attachments
| Action | listDatasetExportFormats / exportRecords / exportRecordsCSV / exportRecordsParquet / exportRecordsGPX / getDatasetAttachments |
|---|---|
| Purpose | Lists a dataset’s export formats, exports its records in a chosen format / CSV / Parquet (snappy/zstd) / GPX, and lists its attachments. |
| Configuration | Configure the base URL via CONNECTOR_ENV_OPENDATA_LIEGE_API_BASE_URL, with API-key authentication via the apikey query parameter. |
| Parameters | Required: dataset_id (and format for exportRecords — e.g. geojson, parquet, xlsx). Optional: select, where, order_by, group_by, limit, refine, exclude, lang, timezone, use_labels, compressed, epsg; CSV delimiter options; parquet_compression; GPX name_field/description_field_list/use_extension. |
| Output | Successful: a file in the requested format, or a list of attachments (MIME type, URL). Failure: 400 / 401 / 429 / 500. |
| Workflow example | Execute exportRecords with dataset_id=geo-data and format=geojson (default EPSG 4326). |
Example Workflow: Open Data Exploration Dashboard
| Datasets | Use getDatasets with select=dataset_id,title to fetch a selectable list. |
|---|---|
| Facets | Execute getRecordsFacets with the selected dataset_id and facet=theme to populate a filter panel. |
| Query & visualize | Use getRecords with refine and where based on user selections, then visualize on a map or chart. |
| Export | Provide download via exportRecords with the same filters and format=csv. |
Support
For technical support, contact custom-connectors-support@isolutions.sa.