DataType Detector

A lightweight Dart package to automatically detect the type of any value, map, or list—including nested JSON, primitives, and iterables. Supports deep parsing of strings into numbers or booleans and provides convenient extensions for strings, string lists, and objects.

Features:

  • Detect Dart primitive types: int, double, bool, String, and null.
  • Detect iterables: List
  • Detect JSON-safe maps and nested JSON structures.
  • Differentiates between JSON maps and arbitrary objects.
  • Deep parsing: convert strings to numbers or booleans automatically.
  • Provides easy-to-use extensions for String, Iterable

Installation:

Add this to your pubspec.yaml: dependencies:

data_type_detector: ^1.0.0

or,

flutter pub add data_type_detector

Then run:

flutter pub get

Usage:

Detect primitive types: print(123.dataType); // DataType.INT print(3.14.dataType); // DataType.DOUBLE print("true".dataType); // DataType.STRING print(true.dataType); // DataType.BOOL print(null.dataType); // DataType.NULL

Deep string parsing: print("123".dataTypeWithOptions(parseable: true)); // DataType.INT print("3.14".dataTypeWithOptions(parseable: true)); // DataType.DOUBLE print("true".dataTypeWithOptions(parseable: true)); // DataType.BOOL

Detect iterables: print(1, 2, 3.dataType); // DataType.INTS print(true, false.dataType); // DataType.BOOLS print("1", "2".dataTypeWithOptions(parseable: true)); // DataType.INTS print("a", "b".dataType); // DataType.STRINGS

Detect maps and JSON: print({"a": 1, "b": "x"}.dataType); // DataType.JSON print({"nested": {"x": 1}}.dataType); // DataType.JSON print({"obj": Object()}.dataType); // DataType.MAP print({"a": 1}, {"b": 2}.dataType); // DataType.JSONS

Detect objects: print(Object().dataType); // DataType.OBJECT print(Object(), Object().dataType); // DataType.OBJECTS

Examples:

import 'package:data_type_detector/data_type_detector.dart';

void main() {
  // -------------------------
  // Primitive values
  // -------------------------
  int intValue = 42;
  double doubleValue = 3.14;
  String stringValue = "hello";
  bool boolValue = true;
  String boolString = "true";
  String intString = "123";

  print(intValue.dataType); // DataType.INT
  print(doubleValue.dataType); // DataType.DOUBLE
  print(stringValue.dataType); // DataType.STRING
  print(boolValue.dataType); // DataType.BOOL
  print(boolString.dataTypeWithOptions(parseable: true)); // DataType.BOOL
  print(intString.dataTypeWithOptions(parseable: true)); // DataType.INT

  // -------------------------
  // Lists / Iterables
  // -------------------------
  List<int> intList = [1, 2, 3];
  List<double> doubleList = [1.1, 2.2, 3.3];
  List<bool> boolList = [true, false, true];
  List<String> stringList = ["1", "2", "3"];
  List<String> stringList2 = ["a", "b", "c"];

  print(intList.dataType); // DataType.INTS
  print(doubleList.dataType); // DataType.DOUBLES
  print(boolList.dataType); // DataType.BOOLS
  print(stringList.dataTypeWithOptions(parseable: true)); // DataType.INTS
  print(stringList2.dataType); // DataType.STRINGS

  // -------------------------
  // Maps / JSON
  // -------------------------
  Map<String, dynamic> jsonMap = {"a": 1, "b": "x", "c": true};
  Map<String, dynamic> nestedJson = {"nested": {"x": 1, "y": [1, 2, 3]}};
  Map<String, Object> normalMap = {"obj": Object()};

  print(jsonMap.dataType); // DataType.JSON
  print(nestedJson.dataType); // DataType.JSON
  print(normalMap.dataType); // DataType.MAP

  // Lists of maps
  List<Map<String, dynamic>> jsonList = [{"a": 1}, {"b": 2}];
  List<Map<String, Object>> mapList = [{"obj": Object()}, {"obj": Object()}];

  print(jsonList.dataType); // DataType.JSONS
  print(mapList.dataType); // DataType.MAPS

  // -------------------------
  // Mixed / Objects
  // -------------------------
  Object obj = Object();
  List<Object> objList = [Object(), Object()];

  print(obj.dataType); // DataType.OBJECT
  print(objList.dataType); // DataType.OBJECTS

  // -------------------------
  // Nested JSON with arrays
  // -------------------------
  Map<String, dynamic> complexJson = {
    "users": [
      {"name": "Alice", "age": 30},
      {"name": "Bob", "age": 25}
    ],
    "active": true
  };

  print(complexJson.dataType); // DataType.JSON
}

Extensions:

  • String? .isBool, .isInt, .isDouble, .isNum
  • Iterable
  • Object? .dataType, .dataTypeWithOptions(parseable: true)

Why use this package?

  • Automatically handle dynamic data in Flutter and Dart.
  • Detect nested JSON without manual checking.
  • Simplify type validation and serialization tasks.
  • Save time and reduce errors when working with dynamic or external data.

License:

MIT License

Libraries

data_type_detector
detector