extract method
Process input
and extract necessary data.
- Note: the output is usually passed to the next
extractor
in the chain.
Implementation
@override
List extract(input) {
final srcInputs = _prepareInputSource(input);
var idx = 0;
if (index < 0) {
idx = srcInputs.length + index;
} else {
idx = index;
}
if (idx >= 0 && idx < srcInputs.length) {
return [srcInputs[idx]];
} else {
return [];
}
}