Loading SVG from cache results in blank/empty SVG

Hi there,

First of all: Fantastic library! ❤️ I've been using it extensively at work 😃

Secondly: I think there is an issue with loading SVGs from cache. It has to do with the following lines of code:

react-svgmt/src/svg-injector.js

Lines 99 to 107 in 0f7ad16

	var loadSvg = function(url, callback) {
	if (svgCache[url] !== undefined) {
	if (svgCache[url] instanceof SVGSVGElement) {
	// We already have it in cache, so use it
	callback(cloneSvg(svgCache[url]));
	} else {
	// We don't have it in cache yet, but we are loading it, so queue this request
	queueRequest(url, callback);
	}

The instance of check always returns false. In fact, I don't think that the SVGSVGElement class even exists (could not find it anywhere).

On top of that, the else block seems to do nothing. It just queues the request, but does not actually perform it. That's a problem because that means when re-requesting a URL, the current SVG gets unmounted, but the new one does not get mounted and the screen remains blank.

This is probably left over from transitioning from react-samy-svg to react-svgmt? Git blame brings me here: https://github.com/hugozap/react-svgmt/blame/0f7ad16521bf1070ff9b2e4bc68ecc1eb6b2a005/src/svg-injector.js#L101

I think it's fine to drop the if-else logic and just check if the url is in the cache:

if (svgCache[url] !== undefined) { 
  // We already have it in cache, so use it
  callback(cloneSvg(svgCache[url]));
}

Let me know your thoughts/insights!

Cheers,
Finn

[rocksinghajay]

@finnwoelm-sdsn Thanks for mentioning this, by doing these above changes will that work? Please check my changes below and it is not working

if (svgCache[url] !== undefined) {
callback(cloneSvg(svgCache[url]));
// if (svgCache[url] instanceof SVGSVGElement) {
// // We already have it in cache, so use it
// callback(cloneSvg(svgCache[url]));
// } else {
// // We don't have it in cache yet, but we are loading it, so queue this request
// queueRequest(url, callback);
// }
}

.

[rocksinghajay]

@hugozap can you please check ?

Hi @rocksinghajay, it's been a while since I've needed this feature.

Are you familiar with patch-package? Here is the patch I had created back then (for v1.1.11 of this repo): https://gist.github.com/finnwoelm-sdsn/2acb102b36744949e71c28df380a2b59