Fryslân Province geoportal (ArcGIS REST)

Base URL

https://geoportaal.fryslan.nl/arcgis/rest/services

Endpoints 9

• GET?f=jsonDirectory: version, folders and services (name + type).
• GET/{map}?f=jsonServices in one folder.
• GET/{dienst}/MapServer?f=jsonService: layers and tables (id, name, group layer or not), maxRecordCount, capabilities, projection, description.
• GET/{dienst}/MapServer/{laag}?f=jsonLayer: fields (name, type, alias, length), geometry type, maxRecordCount, supportedQueryFormats and advancedQueryCapabilities (pagination, statistics, orderBy, distinct).
• GET/{dienst}/MapServer/{laag}/queryQuery features with a where clause or spatial filter; also count (returnCountOnly) and group (outStatistics). Response in JSON, GeoJSON or PBF.
• GET/{dienst}/MapServer/legend?f=jsonLegend per layer: labels and symbols (PNG as base64).
• GET/{dienst}/MapServer/export?bbox=…&bboxSR=4326&size=600,400&format=png&f=imageMap image as PNG for a rectangle; with f=json you get a link to the image. Without bbox: error 'bbox must be specified'.
• GEThttps://geoportaal.fryslan.nl/arcgis/services/{map}/{dienst}/MapServer/WMSServer?request=GetCapabilities&service=WMSWMS 1.3.0 of the same MapServer: path without /rest/ and with /WMSServer. Only for services whose supportedExtensions lists WMSServer.
• GEThttps://geoportaal.fryslan.nl/arcgis/services/{map}/{dienst}/MapServer/WFSServer?service=WFS&request=GetCapabilitiesWFS 2.0 of the same MapServer (only if supportedExtensions lists WFSServer); GetFeature with outputFormat=GEOJSON.

Filtering platform

SQL-like where clause on the layer's fields, plus an optional spatial filter (geometry). Group and count with outStatistics.

Parameters 13

Fields of the example layer 12 · ProvinciaalGeoRegister/PGR2/MapServer/80 (6.694 gebouwen)

Limits and pitfalls

• At most 2.000 features per response (the layer's maxRecordCount; varies per layer, see /{layer}?f=json). If there are more, the response has exceededTransferLimit: true: fetch the rest with resultOffset and resultRecordCount. tested
• No key and no documented rate limit. Take it easy (a few requests per second) and prefer statistics or counts over fetching all features. experience
• Errors come back with HTTP 200 and a JSON object {"error": {"code": 400, …}} ('Failed to execute query.' for an unknown field in where). Always check for an error field, not just the status code. tested
• Besides the REST API, PGR2 also has a WFS 2.0 with 81 feature types (PGR:…). Type names differ from layer names: 'Jongere bouwkunst 1850-1940' is PGR:Jongere_bouwkunst_1850-1940. outputFormat=GEOJSON works. tested
• Accented characters are broken in the data itself: FUNCTIE 'café' is stored as 'caf¿', the same in REST and WFS. tested
• The asbestos roofs layer (533,994 polygons) can be queried publicly, but the metadata says 'For internal use only'. Read the layer description before publishing; layer descriptions often only say ' Bekijk metadata '. experience
• Group layers (with subLayerIds) have no query; query the leaf layers below them. Raster layers have no fields and no count. platform
• The server gives no modification date per service or layer (no editingInfo). How current a layer is, is not stated. tested
• maxRecordCount differs per service (1,000 to 20,000); three services only support f=json. experience

Try it HTTP 200 · 329 ms · 16 Oct

https://geoportaal.fryslan.nl/arcgis/rest/services/ProvinciaalGeoRegister/PGR2/MapServer/80/query?where=1%3D1&outStatistics=[{"statisticType"%3A"count"%2C"onStatisticField"%3A"OBJECTID"%2C"outStatisticFieldName"%3A"n"}]&groupByFieldsForStatistics=HOOFDCAT&orderByFields=n DESC&f=json

{
  "displayFieldName": "",
  "fieldAliases": {
    "HOOFDCAT": "Hoofdcat",
    "n": "n"
  },
  "fields": [
    {
      "name": "HOOFDCAT",
      "type": "esriFieldTypeString",
      "alias": "Hoofdcat",
      "length": 50
    },
    {
      "name": "n",
      "type": "esriFieldTypeInteger",
      "alias": "n"
    }
  ],
  "features": [
    {
      "attributes": {
        "HOOFDCAT": "Woningen en woningbouwcomplexen",
        "n": 3666
      }
    },
    {
      "attributes": {
        "HOOFDCAT": "Boerderij, molen, bedrijf",
        "n": 1571
      }
    }
  ]
}

Shortened response, saved at harvest time. Click the URL for the real, current response.