isFullHtmlPage static method
Checks if the source looks like HTML
Implementation
static bool isFullHtmlPage(String src) {
final _src = src.trim().toLowerCase();
return _src.startsWith(RegExp('<!DOCTYPE html>', caseSensitive: false)) &&
// I didn't forget the closing bracket here.
// Html opening tag may also have some random attributes.
_src.contains(RegExp('<html', caseSensitive: false)) &&
_src.contains(RegExp('</html>', caseSensitive: false));
}