Bring newest changes from main to nullsafety branch

.gitignore

@@ -5,9 +5,10 @@
 # Remove the following pattern if you wish to check in your lock file
 pubspec.lock
 
-# IntelliJ
+# IntelliJ / IDEs
 *.iml
 .idea/
+.vscode/
 
 # Conventional directory for build outputs
 build/

AUTHORS

@@ -3,4 +3,5 @@
 #
 #   Name/Organization <email address>
 
-Adaptant Labs <[email protected]>
+Adaptant Labs <[email protected]>
+Stemco

CHANGELOG.md

@@ -1,3 +1,18 @@
+## 0.2.1
+- Migrated completely to nullsafety
+
+## 0.2.0
+
+- Expose helpers for querying NHTSA DB and accessing extended vehicle information (requested by @ride4sun, issue #8)
+
+## 0.1.4+1
+
+- Revert null-safety changes from stable release to satisfy SDK constraints
+
+## 0.1.4
+
+- Support VINs with 2-character manufacturer IDs in their WMI (reported by @huangkaichang, issue #7)
+- Fix Uri parsing for NHTSA DB REST API
 ## 0.2.1-nullsafety
 
 - Support VINs with 2-character manufacturer IDs in their WMI (reported by @huangkaichang, issue #7)

README.md

@@ -1,7 +1,7 @@
 vin-decoder-dart
 ================
 
-[![Build Status](https://travis-ci.com/adaptant-labs/vin-decoder-dart.svg?branch=master)](https://travis-ci.com/adaptant-labs/vin-decoder-dart#)
+[![Build Status](https://travis-ci.com/adaptant-labs/vin-decoder-dart.svg?branch=master)](https://app.travis-ci.com/github/adaptant-labs/vin-decoder-dart)
 [![Pub](https://img.shields.io/pub/v/vin_decoder.svg)](https://pub.dartlang.org/packages/vin_decoder)
 
 A VIN decoding, validation, and generation library for Dart.

example/vin_decoder_example.dart

@@ -1,7 +1,8 @@
-import 'package:vin_decoder/vin_decoder.dart';
+import 'package:custom_vin_decoder/nhtsa.dart';
+import 'package:custom_vin_decoder/vin_decoder.dart';
 
 void main() async {
-  var vin = VIN(number: 'WP0ZZZ99ZTS392124', extended: true);
+  var vin = VIN(vin: 'WP0ZZZ99ZTS392124', extended: true);
 
   print('WMI: ${vin.wmi}');
   print('VDS: ${vin.vds}');
@@ -10,7 +11,7 @@ void main() async {
   print("Model year is " + vin.modelYear());
   print("Serial number is " + vin.serialNumber());
   print("Assembly plant is " + vin.assemblyPlant());
-  print("Manufacturer is " + vin.getManufacturer()!);
+  print("Manufacturer is " + (vin.getManufacturer() ?? ""));
   print("Year is " + vin.getYear().toString());
   print("Region is " + vin.getRegion());
   print("VIN string is " + vin.toString());
@@ -25,6 +26,12 @@ void main() async {
   var type = await vin.getVehicleTypeAsync();
   print("Type is ${type}");
 
+  var info = await NHTSA.decodeVin(vin.number);
+  print('Plant Country is ' + (info?.value('Plant Country') ?? ""));
+
+  var values = await NHTSA.decodeVinValues(vin.number);
+  print('Manufacturer from NHTSA DB is ' + values?['Manufacturer']);
+
   var generated = VINGenerator().generate();
   print('Randomly Generated VIN is ${generated}');
 }

lib/nhtsa.dart

@@ -0,0 +1,4 @@
+/// Support for querying NHTSA database by VIN.
+library nhtsa;
+
+export 'src/nhtsa_model.dart';

lib/src/nhtsa_model.dart

@@ -2,19 +2,71 @@ import 'package:basic_utils/basic_utils.dart';
 import 'package:http/http.dart' as http;
 import 'dart:convert';
 
+// NHTSA Results not relevant for a specific vehicle can be either null or N/A
+const String _RESULT_NOT_APPLICABLE = 'Not Applicable';
+
+// ignore: avoid_classes_with_only_static_members
+/// A wrapper for the NHTSA REST API
+class NHTSA {
+  static const String _uriBase = 'https://vpic.nhtsa.dot.gov/api/vehicles';
+
+  /// Obtain information about a given [vin] from the NHTSA DB.
+  static Future<NHTSAVehicleInfo?> decodeVin(String vin) async {
+    var path = _uriBase + '/DecodeVin/' + vin + '?format=json';
+    final response = await http.get(Uri.parse(path));
+
+    if (response.statusCode == 200) {
+      return NHTSAVehicleInfo.fromJson(jsonDecode(response.body) as Map<String, dynamic>);
+    }
+
+    return null;
+  }
+
+  /// Obtain a map of key/value pairs containing known values for a given [vin]
+  static Future<Map<String, dynamic>?> decodeVinValues(String vin) async {
+    var path = _uriBase + '/DecodeVinValues/' + vin + '?format=json';
+    final response = await http.get(Uri.parse(path));
+
+    // The DecodeVinValues endpoint returns a single Results object with all
+    // variables and values as an array of encapsulated key/value pairs.
+    // Manually unpack this in order to provide the caller a populated Dart map.
+    if (response.statusCode == 200) {
+      final Map<String, dynamic> data = jsonDecode(response.body) as Map<String, dynamic>;
+      final Map<String, dynamic> map = data['Results'][0] as Map<String, dynamic>;
+      // Discard empty and not applicable entries from map
+      map.removeWhere((key, value) =>
+          value == null || value == _RESULT_NOT_APPLICABLE || value == '');
+      return map;
+    }
+
+    return null;
+  }
+}
+
+/// The result of a single data point from the NHTSA DB for a specific variable.
 class NHTSAResult {
+  /// The value associated with a given [variable] or [variableId]
   String? value;
+
+  /// The ID number associated with a given [value]
   String? valueId;
+
+  /// The variable name
   String? variable;
+
+  /// The ID number of a given [variable]
   int? variableId;
 
-  NHTSAResult({this.value, this.valueId, this.variable, this.variableId});
+  NHTSAResult({required this.value, required this.valueId, required this.variable, required this.variableId});
 
-  NHTSAResult.fromJson(Map<String, dynamic> json) {
-    value = json['Value'];
-    valueId = json['ValueId'];
-    variable = json['Variable'];
-    variableId = json['VariableId'];
+  /// Create a new [NHTSAResult] instance from a fixed JSON payload
+  factory NHTSAResult.fromJson(Map<String, dynamic> json) {
+    return NHTSAResult(
+      value: json['Value'] as String?, 
+      valueId: json['ValueId'] as String?, 
+      variable: json['Variable'] as String?, 
+      variableId: json['VariableId'] as int?
+    );
   }
 
   @override
@@ -23,81 +75,60 @@ class NHTSAResult {
   }
 }
 
+/// Extended vehicle information for a specific VIN obtained from the NHTSA DB.
 class NHTSAVehicleInfo {
-  int? count;
-  String? message;
-  String? searchCriteria;
-  List<NHTSAResult>? results;
+  int count;
+  String message;
+  String searchCriteria;
+  List<NHTSAResult> results = [];
 
   NHTSAVehicleInfo(
-      {this.count, this.message, this.searchCriteria, this.results});
+      {required this.count, required this.message, required this.searchCriteria, required this.results});
 
-  NHTSAVehicleInfo.fromJson(Map<String, dynamic> json) {
-    count = json['Count'];
-    message = json['Message'];
-    searchCriteria = json['SearchCriteria'];
+  /// Create a new [NHTSAVehicleInfo] instance from a fixed JSON payload.
+  factory NHTSAVehicleInfo.fromJson(Map<String, dynamic> json) {
+    List<NHTSAResult> results = [];
     if (json['Results'] != null) {
-      results = [];
       json['Results'].forEach((v) {
-        if (v['Value'] != null) {
-          results!.add(NHTSAResult.fromJson(v));
+        if (v['Value'] != null &&
+            v['Value'] != _RESULT_NOT_APPLICABLE &&
+            v['Value'] != '') {
+          results.add(NHTSAResult.fromJson(v as Map<String, dynamic>));
         }
       });
     }
+    return NHTSAVehicleInfo(
+      count: (json['Count'] as int?) ?? 0,
+      message: (json['Message'] as String?) ?? "",
+      searchCriteria:( json['SearchCriteria'] as String?) ?? "",
+      results: results
+    );
   }
 
-  static String normalizeStringValue(String s) {
+  static String? _normalizeStringValue(String? s) {
+    if (s == null){
+      return null;
+    }
     return s.splitMapJoin(' ',
         onNonMatch: (m) => StringUtils.capitalize(m.toLowerCase()));
   }
 
-  ExtendedVehicleInfo toExtendedVehicleInfo() {
-    final ExtendedVehicleInfo info = ExtendedVehicleInfo();
-
-    results!.forEach((f) {
-      switch (f.variable) {
-        case "Vehicle Type":
-          info.vehicleType = normalizeStringValue(f.value!);
-          break;
-        case "Make":
-          info.make = normalizeStringValue(f.value!);
-          break;
-        case "Model":
-          info.model = normalizeStringValue(f.value!);
-          break;
-      }
-    });
-
-    return info;
-  }
-
-  @override
-  String toString() {
-    return 'NHTSAVehicleInfo[count=$count, message=$message, searchCriteria=$searchCriteria, results=$results]';
+  /// Lookup the value of a variable by its [variableId] in the NHTSA DB results
+  String? valueFromId(int? variableId) {
+    var result = results.singleWhere((e) => e.variableId == variableId,
+        orElse: () => NHTSAResult(value: null, valueId: null, variable: null, variableId: null));
+    return _normalizeStringValue(result.value);
   }
-}
-
-class ExtendedVehicleInfo {
-  String? make;
-  String? model;
-  String? vehicleType;
 
-  static Future<ExtendedVehicleInfo?> getExtendedVehicleInfo(String vin) async {
-    var path = 'https://vpic.nhtsa.dot.gov/api/vehicles/DecodeVin/' +
-        vin +
-        '?format=json';
-    final response = await http.get(Uri.parse(path));
-
-    if (response.statusCode == 200) {
-      var vehicleInfo = NHTSAVehicleInfo.fromJson(jsonDecode(response.body));
-      return vehicleInfo.toExtendedVehicleInfo();
-    }
-
-    return null;
+  /// Lookup the value of a named [variable] in the NHTSA DB results
+  String? value(String variable) {
+    var result =
+        results.singleWhere((e) => e.variable == variable, orElse: () => NHTSAResult(value: null, valueId: null, variable: null, variableId: null));
+    return _normalizeStringValue(result.value);
   }
 
   @override
   String toString() {
-    return 'ExtendedVehicleInfo[make=$make, model=$model, vehicleType=$vehicleType]';
+    return 'NHTSAVehicleInfo[count=$count, message=$message, searchCriteria=$searchCriteria, results=$results]';
   }
 }