crimson 0.0.5 crimson: ^0.0.5 copied to clipboard
Fast, efficient and easy-to-use JSON parser and serializer for Dart.
Fast, efficient and easy-to-use JSON parser and serializer for Dart.
ð§ Crimson is still in early development and is not ready for production use.
Only parsing is supported for now ð§
Features #
- ðïļ Fast: Like really fast. Crimson parses JSON in a single pass.
- ðŧ Easy to use: Crimson is designed to be easy to use and understand.
- ð Flexible: Crimson can partially parse and serialize JSON.
- ðĨķ Freezed support: Crimson supports freezed classes.
- ðŠķ Lightweight: Crimson is lightweight and has no third-party dependencies.
Usage #
After adding Crimson to your pubspec.yaml
, you can start annotating your classes with @json
and optionally @JsonField()
:
import 'package:crimson/crimson.dart';
part 'tweet.g.dart';
@json
class Tweet {
DateTime? createdAt;
String? tweet;
int? favoriteCount;
}
Now you just need to run pub run build_runner build
to generate the necessary code.
import 'package:crimson/crimson.dart';
void main() {
final jsonBytes = downloadTweets();
final crimson = Crimson(jsonBytes);
final tweets = crimson.parseTweetList();
}
That's it! You can now parse and serialize JSON with ease.
Ignoring fields #
Annotate properties with @jsonIgnore
to ignore them:
@json
class Tweet {
DateTime? created_at;
String? tweet;
@jsonIgnore
int? favoriteCount;
}
Renaming fields #
Use the @JsonName()
annotation to rename individual fields:
@json
class Tweet {
@JsonName('created_at')
DateTime? createdAt;
@JsonName('text', aliases: {'alias1', 'alias2'})
String? tweet;
}
The same works for enum values:
@json
enum TweetType {
tweet,
@JsonName('re-tweet')
retweet,
}
If you want to rename all fields or enum values, you can use @jsonKebabCase
and @jsonSnakeCase
:
@jsonKebabCase
class Tweet {
DateTime? createdAt; // created-at
String? tweet; // tweet
int? favoriteCount; // favorite-count
}
@jsonSnakeCase
enum PlaceType {
country, // country
largeCity, // large_city
smallCity, // small_city
}
Custom converters #
You can use custom converters to convert between JSON and Dart types. Just create a class that implements JsonConverter<T>
.
class IntToBoolConverter extends JsonConverter<bool> {
const IntToBoolConverter();
@override
bool fromJson(dynamic json) => json == 1;
@override
dynamic toJson(bool value) => value ? 1 : 0;
}
Then you can annotate your properties with the new converter:
@json
class Tweet {
String? tweet;
@IntToBoolConverter()
bool? isFavorite;
}
Freezed Support #
Crimson supports classes annotated with @freezed
from the freezed package.
import 'package:crimson/crimson.dart';
part 'tweet.g.dart';
part 'tweet.freezed.dart';
@freezed
class Tweet with _$Tweet {
@json
const factory Tweet({
DateTime? created_at,
@JsonField(name: 'text') String? tweet,
int? reply_count,
int? retweet_count,
int? favorite_count,
}) = _Tweet;
}
License #
Copyright 2022 Simon Choi
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.