Internet explorer does not seem to respond to the load/SVGLoad event for SVGImageElements

[atruskie]

We rely on the onload event to clean up the SVG in the distributionVisualisation.js after an image has loaded.

Other advantages include storing successful image downloads so that we do not have to render all the extra stuff needed by empty tiles.

The ultimate result, is that in IE only, when tile images sucessfully load:

• we don't know or can't track this success
• the ugly green placeholder tile remains
• the text on the placeholder tile also remains

Only viable solution is to do HEAD requests to see if files exist before setting the xlink:href attribute on the image element.

See http://stackoverflow.com/questions/30713535/load-svgload-event-for-svgimageelement-in-internet-explorer for progress