issues

Hi, datasette version: "0.26.2" extensions: spatialite: "4.4.0-RC0" sqlite version: "3.22.0"

I have a table of airports with latitude and longitude columns. I've added spatialite (with KNN support). After creating the db using csvs-to-sqlit, I run these commands to setup the spatialite tables:

``` conn.execute('SELECT InitSpatialMetadata(1)')

conn.execute("SELECT AddGeometryColumn('airports', 'point_geom', 4326, 'POINT', 2);")

conn.execute('''UPDATE airports SET point_geom = GeomFromText('POINT('||"longitude"||' '||"latitude"||')',4326);''')

conn.execute("SELECT CreateSpatialIndex('airports', 'point_geom');") ```

I'm attempting to create a canned query and have this in my metadata.json file: "find_airports_nearest_to_point":{ "sql":"SELECT a.pos AS rank, b.id, b.name, b.country, b.latitude AS latitude, b.longitude AS longitude, a.distance / 1000.0 AS dist_km FROM KNN AS a JOIN airports AS b ON (b.rowid = a.fid) WHERE f_table_name = \"airports\" AND ref_geometry = MakePoint( :Long , :Lat ) AND max_items = 10;"} which doesn't seem to perform the templating of the name parameters correctly and I get no results.

Have also tired: MakePoint( || :Long || , || :Lat || ) which returns this error: near "||": syntax error

However I cannot seem to find the correct combination of named parameter syntax (:Lat) or sqlite concatenation operator to make it work. Any ideas if using named parameters inside functions is supported?

Thanks Darren

Hi, Firstly, thanks for your work on datasette, it is a hugely useful tool!

I've been working on a fork [https://github.com/dazzag24/datasette-cluster-map] of datasette-cluster-map to allow the tileserver to be easily switched. Primarily because the tiles being served in the current version use localised text for labels and I'd like to have English used for these names instead.

It uses http://leaflet-extras.github.io/leaflet-providers/preview/ to allow you to simply set the tile provider using a call like so: let tiles = L.tileLayer.provider('Esri.WorldTopoMap'); instead of the current: let tiles = L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', { maxZoom: 19, detectRetina: true, attribution: '© <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors' }), However I've got stuck in trying to work out how to pass the provider string to the plugin. In the documentation: https://datasette.readthedocs.io/en/stable/plugins.html you discuss configuration of plugins and use an example of passing in which latitude and longitude columns should be used. However I cannot seem to see anywhere in the current datasette-cluster-map code where these config params are passed in or used.

Can you please point me to an example or how to pass configuration from the metadata.json down into a plugin. Once I've over come this issue I was wondering if you would be interested in taking this change into your version?

Many thanks Darren