dimsdk 2.1.1

Decentralized Instant Messaging Software Development Kit.

Decentralized Instant Messaging (Dart SDK)

Dependencies

• Latest Versions

Name	Version	Description
Ming Ke Ming (名可名)		Decentralized User Identity Authentication
Dao Ke Dao (道可道)		Universal Message Module
DIMP (去中心化通讯协议)		Decentralized Instant Messaging Protocol

Extensions

Content

extends CustomizedContent

ContentProcessor

import 'package:dimsdk/dimsdk.dart';

import '../../common/protocol/groups.dart';


/*  Command Transform:

    +===============================+===============================+
    |      Customized Content       |      Group Query Command      |
    +-------------------------------+-------------------------------+
    |   "type" : i2s(0xCC)          |   "type" : i2s(0x88)          |
    |   "sn"   : 123                |   "sn"   : 123                |
    |   "time" : 123.456            |   "time" : 123.456            |
    |   "app"  : "chat.dim.group"   |                               |
    |   "mod"  : "history"          |                               |
    |   "act"  : "query"            |                               |
    |                               |   "command"   : "query"       |
    |   "group"     : "{GROUP_ID}"  |   "group"     : "{GROUP_ID}"  |
    |   "last_time" : 0             |   "last_time" : 0             |
    +===============================+===============================+
 */
class GroupHistoryHandler extends BaseCustomizedHandler {
  GroupHistoryHandler(super.facebook, super.messenger);

  bool matches(String app, String mod) => app == GroupHistory.APP && mod == GroupHistory.MOD;

  @override
  Future<List<Content>> handleAction(String act, ID sender, CustomizedContent content, ReliableMessage rMsg) async {
    var transceiver = messenger;
    if (transceiver == null) {
      assert(false, 'messenger lost');
      return [];
    } else if (act == GroupHistory.ACT_QUERY) {
      assert(GroupHistory.APP == content.application);
      assert(GroupHistory.MOD == content.module);
      assert(content.group != null, 'group command error: $content, sender: $sender');
    } else {
      assert(false, 'unknown action: $act, $content, sender: $sender');
      return await super.handleAction(act, sender, content, rMsg);
    }
    Map info = content.copyMap(false);
    info['type'] = ContentType.COMMAND;
    info['command'] = GroupCommand.QUERY;
    Content? query = Content.parse(info);
    if (query is QueryCommand) {
      return await transceiver.processContent(query, rMsg);
    }
    assert(false, 'query command error: $query, $content, sender: $sender');
    String text = 'Query command error.';
    return respondReceipt(text, envelope: rMsg.envelope, content: content);
  }

}


///  Customized Content Processing Unit
///  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
class AppCustomizedProcessor extends CustomizedContentProcessor {
  AppCustomizedProcessor(Facebook facebook, Messenger messenger) : super(facebook, messenger) {
    groupHistoryHandler = createGroupHistoryHandler(facebook, messenger);
  }

  // protected
  GroupHistoryHandler createGroupHistoryHandler(Facebook facebook, Messenger messenger) =>
      GroupHistoryHandler(facebook, messenger);

  // protected
  late final GroupHistoryHandler groupHistoryHandler;

  /// override for your modules
  @override
  CustomizedContentHandler filter(String app, String mod, CustomizedContent content, ReliableMessage rMsg) {
    if (content.group != null) {
      if (groupHistoryHandler.matches(app, mod)) {
        return groupHistoryHandler;
      }
    }
    return super.filter(app, mod, content, rMsg);
  }

}

ContentProcessorCreator

import 'package:dimsdk/dimsdk.dart';

import 'customized.dart';
import 'handshake.dart';


class ClientContentProcessorCreator extends BaseContentProcessorCreator {
  ClientContentProcessorCreator(super.facebook, super.messenger);

  @override
  ContentProcessor? createContentProcessor(String msgType) {
    switch (msgType) {

      // application customized
      case ContentType.APPLICATION:
      case ContentType.CUSTOMIZED:
      case 'application':
      case 'customized':
        return AppCustomizedProcessor(facebook!, messenger!);

    }
    // others
    return super.createContentProcessor(msgType);
  }

  @override
  ContentProcessor? createCommandProcessor(String msgType, String cmd) {
    switch (cmd) {
      case HandshakeCommand.HANDSHAKE:
        return HandshakeCommandProcessor(facebook!, messenger!);
      // ...
    }
    // others
    return super.createCommandProcessor(msgType, cmd);
  }

}

ExtensionLoader

import 'package:dimsdk/plugins.dart';

import '../../common/protocol/handshake.dart';


/// Extensions Loader
/// ~~~~~~~~~~~~~~~~~
class CommonExtensionLoader extends ExtensionLoader {

  @override
  void registerCustomizedFactories() {
    
    // Application Customized
    setContentFactory(ContentType.CUSTOMIZED, 'customized', creator: (dict) => AppCustomizedContent(dict));
    setContentFactory(ContentType.APPLICATION, 'application', creator: (dict) => AppCustomizedContent(dict));
    
  }

  @override
  void registerCommandFactories() {
    super.registerCommandFactories();

    // Handshake
    setCommandFactory(HandshakeCommand.HANDSHAKE, creator: (dict) => BaseHandshakeCommand(dict));

  }

}

Usages

You must load all extensions before your business run:

import 'package:dim_plugins/plugins.dart';

import 'common_loader.dart';


class LibraryLoader {
  LibraryLoader({ExtensionLoader? extensionLoader, PluginLoader? pluginLoader}) {
    this.extensionLoader = extensionLoader ?? CommonExtensionLoader();
    this.pluginLoader = pluginLoader ?? PluginLoader();
  }

  late final ExtensionLoader extensionLoader;
  late final PluginLoader pluginLoader;

  void run() {
    extensionLoader.run();
    pluginLoader.run();
  }

}

void main() {

  var loader = LibraryLoader();
  loader.run();
  
  // do your jobs after all extensions loaded.
  
}

Also, to let your AppCustomizedProcessor start to work, you must override BaseContentProcessorCreator for message types:

1. ContentType.APPLICATION
2. ContentType.CUSTOMIZED

and then set your creator for GeneralContentProcessorFactory in the MessageProcessor.

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Copyright © 2023 Albert Moky