https://github.com/eyeseast/datasette-geojson

Add GeoJSON output to Datasette queries
https://github.com/eyeseast/datasette-geojson

datasette-io datasette-plugin geojson gis sqlite

Last synced: 3 months ago
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Add GeoJSON output to Datasette queries

• Host: GitHub
• URL: https://github.com/eyeseast/datasette-geojson
• Owner: eyeseast
• Created: 2021-06-08T01:33:19.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2024-01-13T01:00:15.000Z (about 1 year ago)
• Last Synced: 2024-10-25T09:47:04.532Z (3 months ago)
• Topics: datasette-io, datasette-plugin, geojson, gis, sqlite
• Language: Python
• Homepage:
• Size: 2.19 MB
• Stars: 12
• Watchers: 4
• Forks: 3
• Open Issues: 7
• Metadata Files:
  • Readme: README.md

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README

        
# datasette-geojson

[![PyPI](https://img.shields.io/pypi/v/datasette-geojson.svg)](https://pypi.org/project/datasette-geojson/)

[![Changelog](https://img.shields.io/github/v/release/eyeseast/datasette-geojson?include_prereleases&label=changelog)](https://github.com/eyeseast/datasette-geojson/releases)

[![Tests](https://github.com/eyeseast/datasette-geojson/workflows/Test/badge.svg)](https://github.com/eyeseast/datasette-geojson/actions?query=workflow%3ATest)

[![License](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](https://github.com/eyeseast/datasette-geojson/blob/main/LICENSE)

Add GeoJSON as an output option for datasette queries.

## Installation

Install this plugin in the same environment as Datasette.

    datasette install datasette-geojson

## Usage

To render GeoJSON, add a `.geojson` extension to any query URL that includes a `geometry` column. That column should be a valid [GeoJSON geometry](https://datatracker.ietf.org/doc/html/rfc7946#section-3.1).

For example, you might use [geojson-to-sqlite](https://pypi.org/project/geojson-to-sqlite/) or [shapefile-to-sqlite](https://pypi.org/project/shapefile-to-sqlite/) to load [neighborhood boundaries](https://bostonopendata-boston.opendata.arcgis.com/datasets/3525b0ee6e6b427f9aab5d0a1d0a1a28_0/explore) into a SQLite database.

```sh

wget -O neighborhoods.geojson https://opendata.arcgis.com/datasets/3525b0ee6e6b427f9aab5d0a1d0a1a28_0.geojson

geojson-to-sqlite boston.db neighborhoods neighborhoods.geojson --spatial-index # create a spatial index

datasette serve boston.db --load-extension spatialite

```

If you're using Spatialite, the geometry column will be in a binary format. If not, make sure the `geometry` column is a well-formed [GeoJSON geometry](https://datatracker.ietf.org/doc/html/rfc7946#section-3.1). If you used `geojson-to-sqlite` or `shapefile-to-sqlite`, you should be all set.

Run this query in Datasette and you'll see a link to download GeoJSON:

```sql

select

  rowid,

  OBJECTID,

  Name,

  Acres,

  Neighborhood_ID,

  SqMiles,

  ShapeSTArea,

  ShapeSTLength,

  geometry

from

  neighborhoods

order by

  rowid

limit

  101

```

Note that the geometry column needs to be explicitly _named_ `geometry` or you won't get the option to export GeoJSON. If you want to use a different column, rename it with `AS`: `SELECT other AS geometry FROM my_table`.

![export geojson](img/export-options.png)

## Development

To set up this plugin locally, first checkout the code. Then create a new virtual environment:

    cd datasette-geojson

    python3 -mvenv venv

    source venv/bin/activate

Or if you are using `pipenv`:

    pipenv shell

Now install the dependencies and tests:

    pip install -e '.[test]'

To run the tests:

    pytest