Time for action – extending ol.control.Control to make your own control

Let's get started. Contrary to most examples, it will need more code than usual. So, to keep things simple, we will explain how to build the sample by retrieving the various code files instead of inlining it. After these operations, we will focus on the important parts of the code to understand them:

  1. Go to the samples directory and retrieve all the css class with the export-geojson string from assets/css/samples.css and copy paste them in your own samples.css file. Next, retrieve a new JavaScript file from https://github.com/eligrey/FileSaver.js/blob/master/FileSaver.js into a new subdirectory, assets/js.
  2. If you don't already have it from Chapter 8, Interacting with Your Map ...

Get OpenLayers 3 : Beginner's Guide now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.