leaflet-gsheets

How to create a simple Leaflet web map that automatically pulls data from two simple Google Sheets tables. Sidebar created using leaflet-sidebar-v2, and Google Sheets connection with PapaParse.

The resultant map can be seen here: https://rdrn.me/leaflet-gsheets/

I explained the process in more length in my blog post here: Leaflet maps with data from Google Sheets.

Steps

1. Open the following two Google Sheets and copy them to your account (top left, "Add to My Drive")

   • leaflet_geoms
   • leaflet_points

2. In each one, do the following three steps:

   • In Google Sheets, go to File -> Publish to the Web -> Publish
   • Choose "Comma-separated values (.csv)" in the dropdown on the right
   • Then copy the link provided just underneath, and save it somewhere

3. Back in GitHub, Fork this repo (top right of this page)

4. Either clone/download your new repo to your machine, or use GitHub's built-in code editor, and open main.js

5. At line 7 where it says "PASTE YOUR URLs HERE", paste the URLs you copied above

6. If you want to display your new website using GitHub Pages:

   • Go to the GitHub page for your repository
   • Click Settings -> go down to GitHub Pages -> under Source choose master branch
   • It may take a while, but the site should become available at your-username.github.io/leaflet-gsheets

7. Customise the Google Sheets with the data you want

8. Customise the JavaScript however you want, there are comments to show where to comment/uncomment code to enable/disable features.

9. Run a local server. First make sure you're in the directory containing index.html etc, and then run:

python3 -m http.server

10. Then open the URL it provides (probably http://0.0.0.0:8000) in a browser!

Adding geometry data

In leaflet_points you can add latitude/longitude pairs for points.

In the leaflet_geoms sheet, you can add points, lines, polygons or multi-version of these, as GeoJSON representations. This can be the full contents of a .geojson file, or really any part of a GeoJSON that ultimately contains a geometry with coordinates.

A good website to use to make these geometries is geojson.io and a good place to find and download geometries for standard things (continents, countries and whatnot) is geojson.xyz.

Some examples. Note that these exclude the "FeatureCollection", "Feature" etc boilerplate, but you can include these and it will work just the same.

// A Point
{
    "type": "Point",
    "coordinates": [18, 36]
}

// A LinteString (a line)
{
    "type": "LineString",
    "coordinates": [
        [1, 42],
        [5, 17],
        [6, 28]
    ]
}

// A Polygon (this one happens to be a square)
{
    "type": "Polygon",
    "coordinates": [[
        [0, 40],
        [3, 40],
        [3, 42],
        [0, 42],
        [0, 40]
      ]]
}

Parting notes

Get in touch if you need a hand!