itemBuilder property Null safety

ItemBuilder<T> itemBuilder

Called for each suggestion returned by suggestionsCallback to build the corresponding widget.

This callback must not be null. It is called by the TypeAhead widget for each suggestion, and expected to build a widget to display this suggestion's info. For example:

itemBuilder: (context, suggestion) {
  return ListTile(
    title: Text(suggestion['name']),
    subtitle: Text('USD' + suggestion['price'].toString())


final ItemBuilder<T> itemBuilder;