getParent function
Finds the name of the parent template.
Implementation
String? getParent(Document document, void Function(JaelError error)? onError) {
var element = document.root;
if (element.tagName.name != 'extend') return null;
var attr = element.attributes.firstWhereOrNull((a) => a.name == 'src');
if (attr == null) {
onError!(JaelError(JaelErrorSeverity.warning,
'Missing "src" attribute in "extend" tag.', element.tagName.span));
return null;
} else if (attr.value is! StringLiteral) {
onError!(JaelError(
JaelErrorSeverity.warning,
'The "src" attribute in an "extend" tag must be a string literal.',
element.tagName.span));
return null;
} else {
return (attr.value as StringLiteral).value;
}
}