Introduction to
GeoJSON Materials

At Central PA GIS Day 2016, I presented an introduction to the GeoJSON data format. A copy of the presentation is available for download. It includes some reference links for further learning.

During the presentation, I gave a demo of how a website can request a JSON file, parse it, and then generate content from that file.

I also gave a demo of a web map that used GeoJSON for overlay data. The properties of features can be used to symbolize features into groups, as well as create unique pop-ups for each feature.

If you decide to use GeoJSON in a Leaflet app, there a few different ways you can add it to the map. You can use a vanilla JavaScript AJAX request, jQuery's getJSON method, or the Leaflet AJAX plugin. I've created a codepen that shows how to use the first two methods.