show and search attributes of vector layer

[JinIgarashi]

Now geohub-data-pipeline uploads flatgeobuf together with PMTiles to Azure Blob Storage.

FGB file path will follow the below rule.

• in the case of multi layers
  • aaa.pmtiles
  • aaa.pmtiles.{layername}.fgb
• in the case of single layer
  • aaa.pmtiles
  • aaa.pmtiles.fgb

We can use this flatgeobuf to search and show attribute table for geohub. also downloading attribute as csv or any other format as well.

To do this, I think we need an endpoint in sveltekit. the below is my current idea of endpoint.

/api/datasets/{id}/attributes/{layerName}

Path params:

• id: dataset ID
• layerName: vector layer name

Query Params:

• format: json, csv
• query: text string to search attributes
• limit: 100 as default
• offset: offset for pagination. default is 0
• geometry: WKT polygon for filtering by geospatial extent
• bbox: bbox (minx, miny, maxx, maxy) for filtering by geospatial extent

Response:

• 200: attribute table data with specified format
• 404: if no flatgeobuf for the data.
• 400: any parameters error
  • if users put both geometry and bbox

frontend side

• add attribute table menu in the sidebar menu of geohub
• If click, show attribute table in the bottom of map.