Dropdowns Industry Counts

Industry counts

Not a dropdown of its own. These are the facility counts shown next to each entry in the Industry dropdown, and they come from a separate query against a different endpoint, so they get their own page.

What it does

Once a state or some counties are selected, each node in the industry tree picks up a number: how many facilities of that kind actually exist in that region. It turns an abstract list of 5596 NAICS codes into something you can steer by, because you can see at a glance which industries are worth filtering on and which will return nothing.

With no region selected there are no counts at all. The query is gated behind having a state, because counting every facility in the country is both slow and not useful for picking a filter.

Counts roll up the tree. A leaf shows what the endpoint returned for that exact code. A parent shows the sum of itself and everything beneath it, computed on the client by rollupCounts(). So a sector node showing 400 means four hundred facilities spread across its descendants, not four hundred facilities tagged with the bare sector code.

There is no fallback. If the query fails you get an empty object and the tree simply shows no numbers. Nothing breaks, you just lose the guidance.

The SPARQL query

Endpoint is federation, not fiokg. This is the important detail: the industry list comes from fiokg but the counts cannot, because counting facilities per region needs the industry graph and the spatial graph joined together, and only federation has both.

SELECT ?industryCode (COUNT(DISTINCT ?facility) AS ?num) WHERE {
  VALUES ?_regionRoot { kwgr:administrativeRegion.USA.23 }
  ?s2 rdf:type kwg-ont:S2Cell_Level13 ;
      spatial:connectedTo ?_regionRoot ;
      kwg-ont:sfContains ?facility .
  ?facility fio:ofIndustry ?industryCode .
  ?industryCode a naics:NAICS-IndustryCode .
} GROUP BY ?industryCode

Line by line:

• VALUES ?_regionRoot { ... } is the selected region. One entry for a whole state, or one per county when counties are picked. 23 is Maine.
• ?s2 rdf:type kwg-ont:S2Cell_Level13 brings in S2 cells, the grid the whole app uses for spatial joins. Each cell covers roughly 1.2 square kilometres.
• spatial:connectedTo ?_regionRoot keeps only the cells inside the chosen region.
• kwg-ont:sfContains ?facility gets the facilities inside those cells.
• ?facility fio:ofIndustry ?industryCode is what kind of facility it is, and the naics:NAICS-IndustryCode line keeps only real NAICS codes rather than any other classification hanging off the same predicate.
• COUNT(DISTINCT ?facility) per code. DISTINCT matters, because a facility sitting on a cell boundary can be reached more than once.

Note the route through S2 cells rather than asking directly which facilities are in Maine. That is the standard pattern across this app: everything spatial goes through S2 Level 13 cells. See docs/ARCHITECTURE.md for why.

Verified against the live endpoint. Maine returns 664 distinct industry codes with counts, from single facility codes like 111110 Soybean Farming through to the busier ones.

What comes back

Full URIs, not bare codes:

http://w3id.org/fio/v1/naics#NAICS-111110   1
http://w3id.org/fio/v1/naics#NAICS-11121    4

Unlike the industry list query, this one does not strip the prefix in SPARQL. The hook does it, splitting on # or / and then removing the leading NAICS-. The result has to match the bare codes the tree is keyed on, so if either side changes shape the numbers silently stop appearing.

How it is wired up

• There is no control of its own. The numbers are passed into HierarchicalSelect as a counts prop at FacilityFilters.tsx:24.
• The data comes from useIndustryCounts(region), called at FacilityFilters.tsx:13.
• The query text is built by buildIndustryCountsQuery().
• It runs through executeSparql() against the federation URL in endpoints.ts.
• The rollup is rollupCounts().

Cached under ['industryCounts', <region key>] with staleTime: Infinity and gated by enabled: !!region?.stateCode. The region key sorts the county codes before joining them, so picking the same counties in a different order reuses the cache instead of refetching.

The hook returns a plain Record<string, number> keyed by bare code, which is what rollupCounts() expects as its leaf counts.

If it looks wrong

No numbers anywhere. Either no state is selected, which is expected, or the federation query failed. There is no fallback, so failure looks exactly like "not selected yet". Check the network tab to tell them apart.

Numbers appear on some nodes but not others. Those codes have no facilities in the selected region. Zero is not returned, so nothing shows.

A parent shows a bigger number than the sum of its visible children. Expected when a child code exists in the counts result but not in the industry list, or when the tree is flatter than NAICS because of a missing intermediate code. The rollup only sums nodes that are in the tree.

Numbers vanish after switching from a state to counties. New cache key, new fetch. If they do not come back, one of the county codes is not resolving to a region root.

Counts look too high for a small county. Facilities on S2 cell boundaries can appear in cells belonging to more than one region. COUNT(DISTINCT ?facility) dedupes within a single result, but the cell to region join is inclusive by design.

See also

• Dropdowns Industry, the tree these numbers decorate
• Dropdowns, the index of all filter controls