(Dart 2) Basic Aqueduct HTTP Controller

reads_controller.dart

/// This is a very basic HTTP Controller for the Aqueduct Dart web framework
/// [https://aqueduct.io/]

import 'dart:async';
import 'dart:io';
import 'package:aqueduct/aqueduct.dart';
import 'package:faker/faker.dart';

const Faker faker = Faker();

/// [Read] is the data model
class Read {
  const Read({this.id, this.title, this.author, this.year});

  /// Had to use [toString()] everywhere since dart throws a 
  /// [The argument type 'dynamic' can't be assigned to the parameter type 'String']
  /// error if we don't.
  factory Read.fromMap(Map<String, dynamic> data) {
    return Read(
        id: int.parse(data['id'].toString()),
        title: data['title'].toString(),
        author: data['author'].toString(),
        year: int.parse(data['year'].toString()));
  }
 
  Map<String, dynamic> toJson() =>
      {"id": id, "title": title, "author": author, "year": year};

  final int id;
  final String title;
  final String author;
  final int year;
}

/// This will act as our temporary "database" for each session.
List<Map<String, dynamic>> reads = [
  {
    "id": 0,
    "title": faker.conference.name(),
    "author": faker.person.name(),
    "year": faker.randomGenerator.integer(2019, min: 1999)
  },
  {
    "id": 1,
    "title": faker.conference.name(),
    "author": faker.person.name(),
    "year": faker.randomGenerator.integer(2019, min: 1999)
  },
  {
    "id": 2,
    "title": faker.conference.name(),
    "author": faker.person.name(),
    "year": faker.randomGenerator.integer(2019, min: 1999)
  },
];

class ReadsController extends ResourceController {
  /// List to store data from the "database".
  List<Read> _data;

  @override
  FutureOr<RequestOrResponse> handle(Request request) {
    /// Our local data list will be updated from the
    /// "database" upon each request.
    _data = reads.map((read) => Read.fromMap(read)).toList();
    return super.handle(request);
  }

  @Operation.get()
  Future<Response> getAllReads() async {
    /// We can get the data from our local data list
    /// since we don't have to change the data in any way.
    return Response.ok(_data)..contentType = ContentType.json;
  }

  @Operation.get('id')
  Future<Response> getRead(@Bind.path('id') int id) async {
    String _error = '';
    Read _read;

    /// We can get the data from our local data list
    /// since we don't have to change the data in any way.
    try {
      _read = _data.firstWhere((read) => read.id == id);
    } catch (e) {
      _error = 'Cannot find read: $e';
    }

    if (_error.isNotEmpty) {
      return Response.notFound(body: _error);
    }

    return Response.ok(_read.toJson())..contentType = ContentType.json;
  }

  @Operation.post()
  Future<Response> createNewRead() async {
    /// Not sending an [id] to the server with postman since a real
    /// database would do that automatically. I'm simulating that here.
    final Map<String, dynamic> body = await request.body.decode()
      ..putIfAbsent("id", () => _data.last.id + 1);

    /// Add the new data to the "database".
    reads.add(body);

    return Response.ok(body)..contentType = ContentType.json;
  }

  @Operation.put('id')
  Future<Response> updateRead(@Bind.path('id') int id) async {
    String _error = '';
    Read _read;
    int _index;

    /// Not sending an id to the server with postman since a real
    /// database would do that automatically. I'm simulating that here.
    final Map<String, dynamic> body = await request.body.decode()
      ..putIfAbsent("id", () => id);

    try {
      _index = reads.indexWhere((read) => read['id'] == id);
    } catch (e) {
      _error = 'Cannot find read: $e';
    }

    if (_error.isNotEmpty) {
      return Response.notFound(body: _error);
    }

    _read = Read.fromMap(body);

    /// Updating the "database".
    reads[_index] = _read.toJson();

    final Map<String, dynamic> result = {
      "message": "Updated read",
      "read": _read.toJson()
    };

    return Response.ok(result)..contentType = ContentType.json;
  }

  @Operation.delete('id')
  Future<Response> deleteRead(@Bind.path('id') int id) async {
    String _error = '';
    int _index;

    /// We need to find the object from the
    /// "database" and not our local data list.
    try {
      _index = reads.indexWhere((read) => read['id'] == id);
    } catch (e) {
      _error = 'Cannot find read: $e';
    }

    if (_error.isNotEmpty) {
      return Response.notFound(body: _error);
    }

    /// Remove it from the "database".
    reads.removeAt(_index);

    return Response.ok('Deleted a read')..contentType = ContentType.json;
  }
}