Working with PostGIS data from within Leaflet.js (or any other client side mapping API)

This 3-part mini-course is my attempt to explain the basic concepts of working with PostGIS data from within the Leaflet.js mapping API.  Technically this is not Leaflet programming. In this scenario Leaflet.js simply becomes the canvas on which your geospatial data is displayed on a web map.  All of the interaction with the geospatial data occur through very common and standard methods of working with enterprise level databases, but with a geospatial twist. Continue reading “Working with PostGIS data from within Leaflet.js (or any other client side mapping API)”

Deploying a PostGIS database Part 2 – Web hosting service

This video goes through the process of signing up for a web hosting service with A2 hosting. You can literally have an instance of PostGIS up and running in half an hour for under $5/month that can be accessed from your own web map or from other clients such as QGIS.

What makes A2 Hosting so good for GIS applications is that they offer PostgreSQL databases in their standard cPanel package which means that you can easily install and use PostGIS. Most web hosting services only offer MySQL although you may be able to have them install PostgreSQL for you. Continue reading “Deploying a PostGIS database Part 2 – Web hosting service”

New Course: Mobile GIS and Mapping Applications with Leaflet

Mobile GIS and Mapping Applications with Leaflet

This course is available now on Udemy.com. It will show you how to create a mobile specific mapping application using Leaflet.js including

  • Formatting your web application for mobile device screens
  • Understanding touch screens and adapting your web app for them
  • Making your web app look and feel like a native application
  • Detecting if the user is using a mobile device
  • Detecting if the user is online or not
  • Getting the most out of geolocation
  • Adding simple charts to your application
  • Using web storage to save the state of your application
  • Using web storage to store local versions of vector data
  • Using the Application Cache API to load a local version of your application for off-line use
  • Creating custom base maps with QGIS and QTiles
  • Adding custom base maps to the application cache for offline use

Continue reading “New Course: Mobile GIS and Mapping Applications with Leaflet”

Adding Legends to your Leaflet Web Map

I’ve just added a bonus lecture to my course on client side programming with Leaflet.  I had a student ask about creating legends for Leaflet maps and I agreed that this was an important missing piece that I had neglected in the main part of the course. I want this course to be comprehensive and so my intention is to continue adding and updating content as needed to provide the best value for my students. Continue reading “Adding Legends to your Leaflet Web Map”

Spatial analysis in Leaflet with Turf.js (Part 3 – Line intersection)

In this video I demonstrate how to use  Turf.js to  return the intersection of lines and polygons.  There is not a straightforward way to perform this analysis in Turf.js but Turf.js is better thought of as a toolbox than a packaged solution. And turf.js does provide a number of tools that can be used in conjunction to perform this analysis. Continue reading “Spatial analysis in Leaflet with Turf.js (Part 3 – Line intersection)”