stream-chat-flutter/packages/stream_chat/lib/src/models/event.dart

import 'package:json_annotation/json_annotation.dart';
import 'package:stream_chat/src/models/channel_model.dart';
import 'package:stream_chat/src/models/message.dart';
import 'package:stream_chat/src/models/serialization.dart';
import 'package:stream_chat/stream_chat.dart';

part 'event.g.dart';

/// The class that contains the information about an event
@JsonSerializable()
class Event {
  /// Constructor used for json serialization
  Event({
    this.type,
    this.cid,
    this.connectionId,
    this.createdAt,
    this.me,
    this.user,
    this.message,
    this.totalUnreadCount,
    this.unreadChannels,
    this.reaction,
    this.online,
    this.channel,
    this.member,
    this.channelId,
    this.channelType,
    this.parentId,
    this.extraData,
  }) : isLocal = true;

  /// Create a new instance from a json
  factory Event.fromJson(Map<String, dynamic> json) =>
      _$EventFromJson(Serialization.moveToExtraDataFromRoot(
        json,
        topLevelFields,
      ))
        ..isLocal = false;

  /// The type of the event
  /// [EventType] contains some predefined constant types
  final String type;

  /// The channel cid to which the event belongs
  final String cid;

  /// The channel id to which the event belongs
  final String channelId;

  /// The channel type to which the event belongs
  final String channelType;

  /// The connection id in which the event has been sent
  final String connectionId;

  /// The date of creation of the event
  final DateTime createdAt;

  /// User object of the health check user
  final OwnUser me;

  /// User object of the current user
  final User user;

  /// The message sent with the event
  final Message message;

  /// The channel sent with the event
  final EventChannel channel;

  /// The member sent with the event
  final Member member;

  /// The reaction sent with the event
  final Reaction reaction;

  /// The number of unread messages for current user
  final int totalUnreadCount;

  /// User total unread channels
  final int unreadChannels;

  /// Online status
  final bool online;

  /// The id of the parent message of a thread
  final String parentId;

  /// True if the event is generated by this client
  bool isLocal;

  /// Map of custom channel extraData
  @JsonKey(includeIfNull: false)
  final Map<String, dynamic> extraData;

  /// Known top level fields.
  /// Useful for [Serialization] methods.
  static final topLevelFields = [
    'type',
    'cid',
    'connection_id',
    'created_at',
    'me',
    'user',
    'message',
    'total_unread_count',
    'unread_channels',
    'reaction',
    'online',
    'channel',
    'member',
    'channel_id',
    'channel_type',
    'parent_id',
    'is_local',
  ];

  /// Serialize to json
  Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
        _$EventToJson(this),
        topLevelFields,
      );

  /// Creates a copy of [Event] with specified attributes overridden.
  Event copyWith({
    String type,
    String cid,
    String channelId,
    String channelType,
    String connectionId,
    DateTime createdAt,
    OwnUser me,
    User user,
    Message message,
    EventChannel channel,
    Member member,
    Reaction reaction,
    int totalUnreadCount,
    int unreadChannels,
    bool online,
    String parentId,
    Map<String, dynamic> extraData,
  }) =>
      Event(
        type: type ?? this.type,
        cid: cid ?? this.cid,
        connectionId: connectionId ?? this.connectionId,
        createdAt: createdAt ?? this.createdAt,
        me: me ?? this.me,
        user: user ?? this.user,
        message: message ?? this.message,
        totalUnreadCount: totalUnreadCount ?? this.totalUnreadCount,
        unreadChannels: unreadChannels ?? this.unreadChannels,
        reaction: reaction ?? this.reaction,
        online: online ?? this.online,
        channel: channel ?? this.channel,
        member: member ?? this.member,
        channelId: channelId ?? this.channelId,
        channelType: channelType ?? this.channelType,
        parentId: parentId ?? this.parentId,
        extraData: extraData ?? this.extraData,
      );
}

/// The channel embedded in the event object
@JsonSerializable()
class EventChannel extends ChannelModel {
  /// Constructor used for json serialization
  EventChannel({
    this.members,
    String id,
    String type,
    String cid,
    ChannelConfig config,
    User createdBy,
    bool frozen,
    DateTime lastMessageAt,
    DateTime createdAt,
    DateTime updatedAt,
    DateTime deletedAt,
    int memberCount,
    Map<String, dynamic> extraData,
  }) : super(
          id: id,
          type: type,
          cid: cid,
          config: config,
          createdBy: createdBy,
          frozen: frozen,
          lastMessageAt: lastMessageAt,
          createdAt: createdAt,
          updatedAt: updatedAt,
          deletedAt: deletedAt,
          memberCount: memberCount,
          extraData: extraData,
        );

  /// Create a new instance from a json
  factory EventChannel.fromJson(Map<String, dynamic> json) =>
      _$EventChannelFromJson(Serialization.moveToExtraDataFromRoot(
        json,
        topLevelFields,
      ));

  /// A paginated list of channel members
  final List<Member> members;

  /// Known top level fields.
  /// Useful for [Serialization] methods.
  static final topLevelFields = [
    'members',
    ...ChannelModel.topLevelFields,
  ];

  /// Serialize to json
  @override
  Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
        _$EventChannelToJson(this),
        topLevelFields,
      );
}