Transform JSON Data and View Webcams

We use Manifold Release 9 (https://manifold.net/index.shtml) to extract data from JSON text to create a map of webcam locations in France, allowing us in Manifold to rapidly click to view what any webcam shows. We take advantage of Manifold's unique ability to work with data in tables to rapidly accomplish a task that would be painful, if not completely impossible, in any other GIS.

We begin with a Javascript .js file that we scraped from a Leaflet web map application that shows traffic webcams in France. We use Notepad to prep that .js file for use as a .csv. We import the CSV into Manifold and then we use the Transform pane to quickly create object geometry and to extract individual JSON named values from a JSON string field into new, individual columns for each record, including a "url" field that gives a URL for viewing each webcam.

We style the url field to allow Manifold to automatically launch that URL in a web browser when we want. We show how to replace web character specifications in text fields with french characters, replacing text like "é" with "é" to match the original French.

We create a map using Bing streets as a background layer, so we can pan and zoom around France and view any webcam in the map. All the above takes only 15 minutes in Manifold, start to finish, showing every detail with no editing to cut out any time. Super! Works in the free Manifold Viewer (https://manifold.net/viewer/), too!

Note: The video shows techniques to manipulate data scraped from the web into a form useful for GIS. However, many governments around the world publish information on the locations and URLs of traffic webcams in formats like CSV or shapefiles that require no transformation. Download traffic webcam data from your local government site and create a Manifold project that lets you click on webcams near your home, to see how traffic might affect your travel plans!