Got first prototype working using asyncinject and it's pretty nice: ```diff diff --git a/datasette/views/table.py b/datasette/views/table.py index ad45ecd3..c8690b22 100644 --- a/datasette/views/table.py +++ b/datasette/views/table.py @@ -2,6 +2,7 @@ import asyncio import itertools import json

+from asyncinject import Registry import markupsafe

from datasette.plugins import pm @@ -538,57 +539,60 @@ class TableView(DataView): # Execute the main query! results = await db.execute(sql, params, truncate=True, **extra_args)

• Calculate the total count for this query

• count = None
• if (
• not db.is_mutable
• and self.ds.inspect_data
• and count_sql == f"select count(*) from {table_name} "
• ):

• We can use a previously cached table row count

• try:
• count = self.ds.inspect_data[database_name]["tables"][table_name][
• "count"
• ]
• except KeyError:

• pass

• Otherwise run a select count(*) ...

• if count_sql and count is None and not nocount:
• try:
• count_rows = list(await db.execute(count_sql, from_sql_params))
• count = count_rows[0][0]
• except QueryInterrupted:

• pass

• Faceting

• if not self.ds.setting("allow_facet") and any(
• arg.startswith("_facet") for arg in request.args
• ):
• raise BadRequest("_facet= is not allowed")

• Resolve extras

• extras = _get_extras(request)
• if request.args.getlist("_facet"):

• extras.add("facet_results")

• pylint: disable=no-member

• facet_classes = list(
• itertools.chain.from_iterable(pm.hook.register_facet_classes())
• )
• facet_results = {}
• facets_timed_out = []
• facet_instances = []
• for klass in facet_classes:
• facet_instances.append(
• klass(
• self.ds,
• request,
• database_name,
• sql=sql_no_order_no_limit,
• params=params,
• table=table_name,
• metadata=table_metadata,
• row_count=count,
• )
• async def extra_count():

• Calculate the total count for this query

• count = None
• if (
• not db.is_mutable
• and self.ds.inspect_data
• and count_sql == f"select count(*) from {table_name} "
• ):

• We can use a previously cached table row count

• try:
• count = self.ds.inspect_data[database_name]["tables"][table_name][
• "count"
• ]
• except KeyError:
• pass +

• Otherwise run a select count(*) ...

• if count_sql and count is None and not nocount:
• try:
• count_rows = list(await db.execute(count_sql, from_sql_params))
• count = count_rows[0][0]
• except QueryInterrupted:
• pass
• return count +
• async def facet_instances(extra_count):
• facet_instances = []
• facet_classes = list(
• itertools.chain.from_iterable(pm.hook.register_facet_classes()) )
• for facet_class in facet_classes:
• facet_instances.append(
• facet_class(
• self.ds,
• request,
• database_name,
• sql=sql_no_order_no_limit,
• params=params,
• table=table_name,
• metadata=table_metadata,
• row_count=extra_count,
• )
• )
• return facet_instances +
• async def extra_facet_results(facet_instances):
• facet_results = {}

• facets_timed_out = []

• async def execute_facets(): if not nofacet: # Run them in parallel facet_awaitables = [facet.facet_results() for facet in facet_instances] @@ -607,9 +611,13 @@ class TableView(DataView): facet_results[key] = facet_info facets_timed_out.extend(instance_facets_timed_out)

• suggested_facets = []

• return {
• "results": facet_results,
• "timed_out": facets_timed_out,

• }

• async def execute_suggested_facets():

• async def extra_suggested_facets(facet_instances):
• suggested_facets = [] # Calculate suggested facets if ( self.ds.setting("suggest_facets") @@ -624,8 +632,15 @@ class TableView(DataView): ] for suggest_result in await gather(*facet_suggest_awaitables): suggested_facets.extend(suggest_result)
• return suggested_facets +

• Faceting

• if not self.ds.setting("allow_facet") and any(
• arg.startswith("_facet") for arg in request.args
• ):

• raise BadRequest("_facet= is not allowed")

• await gather(execute_facets(), execute_suggested_facets())

• pylint: disable=no-member

   # Figure out columns and rows for the query
   columns = [r[0] for r in results.description]
  

  @@ -732,17 +747,56 @@ class TableView(DataView): rows = rows[:page_size]

   # human_description_en combines filters AND search, if provided
  

  • human_description_en = filters.human_description_en(
  • extra=extra_human_descriptions
  • )
  • async def extra_human_description_en():
  • human_description_en = filters.human_description_en(
  • extra=extra_human_descriptions
  • )
  • if sort or sort_desc:
  • human_description_en = " ".join(
  • [b for b in [human_description_en, sorted_by] if b]
  • )

  • return human_description_en

    if sort or sort_desc: sorted_by = "sorted by {}{}".format( (sort or sort_desc), " descending" if sort_desc else "" ) - human_description_en = " ".join( - [b for b in [human_description_en, sorted_by] if b] - ) + + async def extra_next_url(): + return next_url + + async def extra_columns(): + return columns + + async def extra_primary_keys(): + return pks + + registry = Registry( + extra_count, + extra_facet_results, + extra_suggested_facets, + facet_instances, + extra_human_description_en, + extra_next_url, + extra_columns, + extra_primary_keys, + ) + + results = await registry.resolve_multi( + ["extra_{}".format(extra) for extra in extras] + ) + data = { + "ok": True, + "rows": rows[:page_size], + "next": next_value and str(next_value) or None, + } + data.update({ + key.replace("extra_", ""): value + for key, value in results.items() + if key.startswith("extra_") + and key.replace("extra_", "") in extras + }) + return Response.json(data, default=repr)

    async def extra_template(): nonlocal sort @@ -1334,3 +1388,11 @@ class TableDropView(BaseView):

    await db.execute_write_fn(drop_table) return Response.json({"ok": True}, status=200) + + +def _get_extras(request): + extra_bits = request.args.getlist("_extra") + extras = set() + for bit in extra_bits: + extras.update(bit.split(",")) + return extras With that in place, `http://127.0.0.1:8001/content/releases?author=25778&_size=1&_extra=count,primary_keys,columns&_facet=author` returns:json { "ok": true, "rows": [ { "html_url": "https://github.com/eyeseast/geocode-sqlite/releases/tag/0.1.2", "id": 30926270, "author": { "value": 25778, "label": "eyeseast" }, "node_id": "MDc6UmVsZWFzZTMwOTI2Mjcw", "tag_name": "0.1.2", "target_commitish": "master", "name": "v0.1.2", "draft": 0, "prerelease": 1, "created_at": "2020-09-08T17:48:24Z", "published_at": "2020-09-08T17:50:15Z", "body": "Basic API is in place, with CLI support for Google, Bing, MapQuest and Nominatum (OSM) geocoders.", "repo": { "value": 293361514, "label": "geocode-sqlite" }, "reactions": null, "mentions_count": null } ], "next": "30926270", "primary_keys": [ "id" ], "columns": [ "html_url", "id", "author", "node_id", "tag_name", "target_commitish", "name", "draft", "prerelease", "created_at", "published_at", "body", "repo", "reactions", "mentions_count" ], "count": 25, "facet_results": { "results": { "author": { "name": "author", "type": "column", "hideable": true, "toggle_url": "/content/releases?author=25778&_size=1&_extra=count%2Cprimary_keys%2Ccolumns", "results": [ { "value": 25778, "label": "eyeseast", "count": 25, "toggle_url": "http://127.0.0.1:8001/content/releases?_size=1&_extra=count%2Cprimary_keys%2Ccolumns&_facet=author", "selected": true } ], "truncated": false } }, "timed_out": [] } } ```