Dart Metaprogramming - Post Service

post-service.dart

import 'package:core/core.dart';
import 'package:api_sdk/types/reflector.dart';
import 'package:api_sdk/framework/auth-provider.dart';
import 'package:api_sdk/framework/data-provider.dart';
import 'package:api_sdk/framework/api-route.dart';
import 'package:api_sdk/framework/api-method.dart';
import 'package:api_sdk/framework/api-service.dart';
import 'package:core/models/user.dart';

abstract class PostQuery {

    // static final String newImage = 'SELECT id, first_name, last_name FROM users';
    static final String find = 'SELECT id, user_id, image_id, content FROM posts WHERE id = @id';
    static final String user = 'SELECT id, user_id, image_id, content FROM posts WHERE user_id = @user_id';
    static final String create = 'SELECT create_post((@user_id, @image_id, @content)::new_post)';
    static final String delete = 'SELECT delete_post(@id)';
}

@RoutePath('/posts')
class PostService extends APIService {

    PostService(): super();

    @JSON
    @POST('/')
    Future<dynamic>create(NewPost info) async =>
        DataProvider.queryOne(PostQuery.create, values: info.data);

    @JSON
    @GET('/:id')
    @authenticate
    Future<Post>find(String id) async =>
        Reflector.of<Post>(await DataProvider.queryOne(PostQuery.find, values: {'id':id}));

    @JSON
    @GET('/user/:user_id')
    @authenticate
    Future<List<Post>>user(String user_id) async {
        List<Post> posts = [];
        List<dynamic> result = (await DataProvider.query(PostQuery.user, values: {'user_id':user_id}));
        await result.forEach((element) => posts.add(Reflector.of<Post>(element.values.first)));
        return posts;
    }

    @JSON
    @DELETE('/:id')
    @authenticate
    Future<dynamic>delete(String id, { AuthenticatedUser user }) async {
        if ((await find(id)).user_id != user.id) throw Exception('Not authorized');
        return DataProvider.queryOne(PostQuery.delete, values: { 'id': id });
    }
}