field_delegate

Description:

field delegate

field_delegate #
class Field is an abstract mutable field delegate that can be used as an interface to access different data sources.
See example usage in shared_preferences_field_delegate
Usage #
The class Field contains value getter, setter and a stream of changes
Field<int> intField;
int value = intField.get();
Future<void> result = intField.set(1);
Stream<int> changes = intField.onChanged;
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You can map a value of Field to another type with Field.map method
Field<int> intField;
Field<String> mappedField = Field.map<int, String>(
source: intField,
mapToSource: (value) => int.parse(value),
mapFromSource: (value) => value.toString(),
);
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If you have a nullable Field, you can map it to a non-nullable Field with a default value. Use Field.notNullable function for it
Field<int?> intNullableField;
Field<int> intNotNullableField = Field.notNullable(
source: nullableFiled,
defaultValue: 0,
);
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