e.g. https://calands.datasettes.com/calands/superunits_with_maps?_search=golden

Refs simonw/datasette-leaflet#5

If you have datasette-pretty-json installed this plugin won't take effect.

It feels bad when this plugin renders 1,000 maps because someone ran a big custom query.

Could resolve this by only loading the first ten results, and using a grey square for others which can be clicked to load the map for it.

GeoJSON can get big. It would be neat if this library could simplify giant GeoJSON shapes before attempting to render them.

Leaflet ships with a simplify() helper function: https://leafletjs.com/reference-1.3.0.html#lineutil-simplify

Also available as a separate library (with a really nice interactive demo): http://mourner.github.io/simplify-js/

Turf has a version of this that can be applied to GeoJSON documents directly: http://turfjs.org/docs/#simplify

The tricky part is picking the right tolerance value.

Hi,
I'm trying to get to know some of your awesome plugins for datasette.

But when I try to use this plugin (or https://github.com/eyeseast/datasette-geojson-map) and run datasette locally, the maps never show up. I only see the error:
Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/plain". Strict MIME type checking is enforced for module scripts per HTML spec.
in the console.
This happens with Firefox as well as with Chromium browsers.

Right now the GeoJSON output in the HTML on the page can look like this:

{
  "type":"MultiPolygon",
  "coordinates":[[[[-122.4457678900319,37.77292891669105],[-122.441075063058,37.77352490695095]...

https://en.wikipedia.org/wiki/Decimal_degrees#Precision says that 0.00001 should be accurate to within around a meter.

Hi,
I face an error when installing the plugin:

1. From the console, as a standard user (non root), I execute datasette install datasette-leaflet-geojson
2. The following error is thrown:

File "/home/stsinc/.local/bin/datasette", line 5, in <module>
    from datasette.cli import cli
  File "/home/stsinc/.local/lib/python3.10/site-packages/datasette/cli.py", line 17, in <module>
    from .app import (
  File "/home/stsinc/.local/lib/python3.10/site-packages/datasette/app.py", line 39, in <module>
    from .views.database import database_download, DatabaseView, TableCreateView
  File "/home/stsinc/.local/lib/python3.10/site-packages/datasette/views/database.py", line 33, in <module>
    from datasette.plugins import pm
  File "/home/stsinc/.local/lib/python3.10/site-packages/datasette/plugins.py", line 27, in <module>
    pm.load_setuptools_entrypoints("datasette")
  File "/usr/local/lib/python3.10/dist-packages/pluggy/_manager.py", line 398, in load_setuptools_entrypoints
    plugin = ep.load()
  File "/usr/lib/python3.10/importlib/metadata/__init__.py", line 171, in load
    module = import_module(match.group('module'))
  File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "/home/stsinc/.local/lib/python3.10/site-packages/datasette_geojson_map/__init__.py", line 5, in <module>
    from datasette_geojson import can_render_geojson
ModuleNotFoundError: No module named 'datasette_geojson'

My hunch is that there is a naming error with a dependency: 'datasette_geojson' instead of 'datasette-geojson'

The problem with the current map-per-row approach is that it often puts 100 (or even 1000) separate maps on the page, which feels inefficient - and rude to the map tile providers.

Does the plugin need enabling somewhere in order to use it?

I'm trying to render a shapefile column in a SpatiaLite table using a query of the form:

SELECT name, AsGeoJSON(wgs84) FROM adminboundaries LIMIT 3

but all I get is the text output?

I tried a local install:

pip install --upgrade datasette
pip install --upgrade datasette-leaflet-geojson

datasette -p 8003 adminboundaries.db  --load-extension=/usr/local/lib/mod_spatialite.dylib

and a Docker install:

docker run datasetteproject/datasette pip install datasette-leaflet-geojson

docker commit $(docker ps -lq) psychemedia/geodatasette

docker run -d -p 8002:8001 -v `pwd`:/mnt psychemedia/geodatasette \
    datasette -p 8001 -h 0.0.0.0 /mnt/adminboundaries.db  --load-extension=/usr/local/lib/mod_spatialite.so

and got the same result in each case (OS/X, Chrome)?

As of Datasette 0.24 content in cells is truncated, which doesn't play well with this plugin: simonw/datasette#330

Need to switch to fetching the raw JSON instead.

The JavaScript should only be injected on pages that are displaying a table. It currently gets injected everywhere including the Datasette instance index.html homepage.

Just got this error on a table page that didn't hold any GeoJSON. I think it's because that table has a properties column containing JSON that isn't a fit for GeoJSON.

Table schema (from datasette-extract):

CREATE TABLE [_datasette_extract] (
   [id] TEXT PRIMARY KEY,
   [database_name] TEXT,
   [table_name] TEXT,
   [created] TEXT,
   [properties] TEXT,
   [completed] TEXT,
   [error] TEXT,
   [num_items] INTEGER
, [instructions] TEXT)

Example record:

{
    "id": "01HRCSG2XC60AK6E3PNRFBJ1RX",
    "database_name": "data",
    "table_name": "new_york_state_rfps",
    "created": "2024-03-07 15:46:18",
    "properties": "{\"award_number\": {\"type\": \"integer\"}, \"group\": {\"type\": \"integer\"}, \"award_title\": {\"type\": \"string\"}, \"type\": {\"type\": \"string\"}, \"keywords\": {\"type\": \"string\"}}",
    "completed": "2024-03-07 15:46:37",
    "error": "table new_york_state_rfps has no column named group...,",
    "num_items": 7,
    "instructions": null
}

I think I must be misunderstanding something about how the GeoJSON based maps are meant to interact with SpatiaLite.

In order to get familiar with the spatial possibilities of Datasette, I used ogr2ogr to convert the US Census DP1 state/county/tract level geodatabase into an SQLite database, with the SpatiaLite extensions installed:

ogr2ogr -f SQLite census2010.db census2010.gdb

Then I attempted to serve this SpatiaLite database using Datasette, with the datasette-leaflet-geojson plugin installed:

datasette serve census2010.db --load-extension=spatialite

The geometry column (named shape) shows up as downloadable binaries, rather than maps, but I think this is maybe the expected behavior, as the datasette-leaflet-geojson plugin will only render maps if GeoJSON is found, right? So then I did a query, and used AsGeoJSON(shape) to try and create a GeoJSON column which would trigger map creation by the plugin, but instead all I got was a blank column...

select shape, AsGeoJSON(shape), geoid10, stusps10, name10 from state_2010census_dp1 order by stusps10

I went ahead and published it to GCP using:

datasette publish cloudrun \
    --memory=2Gi \
    --install=datasette-leaflet-geojson \
    --spatialite \
    --name censusdp1-datasette \
    census2010.db

and you can see the results of the query here.

None of this seems to have generated any visible errors in my browser on in the logs.

The behavior I expected was that the AsGeoJSON() call would convert the WKB geometry to a GeoJSON object, and then the datasette-leaflet-geojson plugin would pick it up and render maps of the converted geometries.