tryToList<T> function

List<T>? tryToList<T>(dynamic object, { Object? mapKey, int? listIndex, })

Attempts to convert an object to a List of type T, or returns null if conversion is not possible. mirroring the same static method in the ConvertObject, providing alternative easy less code usage options.

• If the object is already a List of type T, it is returned as-is.
• If the object is a single instance of type T, it returns a List containing that object.
• If the object is a Map, and mapKey is provided, it returns a List of the values for that key across all map entries.
• If the object is a Map with values of type T and no mapKey is provided, it returns a List of all the map's values.
• If the object is a List, and listIndex is provided, it attempts to return a List containing the element at that index from each list in the original list.
• If the object cannot be converted to a List of type T, an error is logged, and null is returned.

object The object to be converted to a List of type T. mapKey (Optional) Specifies the key to extract values from a Map object. listIndex (Optional) Specifies the index to extract elements from a List object.

Returns a List of type T if conversion is successful, otherwise null.

Example usage:

final object1 = [1, 2, 3];
final list1 = tryToList<int>(object1); // [1, 2, 3]

final object2 = 42;
final list2 = tryToList<int>(object2); // [42]

final object3 = {'a': 1, 'b': 2};
final list3 = tryToList<int>(object3); // [1, 2]

final object4 = {'a': [1, 2], 'b': [3, 4]};
final list4 = tryToList<int>(object4, mapKey: 'a'); // [1, 2]

final object5 = [[1, 2], [3, 4]];
final list5 = tryToList<int>(object5, listIndex: 0); // [1, 3]

final object6 = 'Hello';
final list6 = tryToList<int>(object6); // null (logs an error)

final object7 = null;
final list7 = tryToList<int>(object7); // null

Implementation

List<T>? tryToList<T>(
  dynamic object, {
  Object? mapKey,
  int? listIndex,
}) =>
    ConvertObject.tryToList(object, mapKey: mapKey, listIndex: listIndex);