getContent method
Returns the content after resolve it.
Implementation
Future<String?> getContent() async {
if (hasContent) return _content;
if (resource == null) return null;
try {
_readFuture = resource!.readAsString();
var c = await _readFuture;
_onLoad(c, false);
return c;
} catch (e) {
_onLoad(null, true);
return null;
}
}