[GramJS] - Getting participant object in group and channel chats

getParticipants.ts

// The code below works for both gramjs in node and grm in deno

.... // other imports above


import ChannelParticipants = Api.channels.ChannelParticipants;
import ChatParticipant = Api.ChatParticipant;
import ChannelParticipant = Api.ChannelParticipant;


/**
 * Get all channel participants
 * @see {@link https://github.com/Dionid/teleadmin/blob/e96bf05ad7b39d27868077303a1c69638dcb6a84/main-back/src/libs/telegram-js/get-channel-partisipants.ts#L11}
 * 
 * @param client TelegramClient
 * @param channel Channel
 * @param offset number
 * @param limit number
 * @param aggregated ChannelParticipants
 * @returns Promise<Api.channels.TypeChannelParticipants>
 */
export const getAllChannelParticipants = async (
    client: TelegramClient,
    channel: Api.TypeEntityLike,
    offset = 0,
    limit = 999999,
    aggregated?: ChannelParticipants,
): Promise<Api.channels.TypeChannelParticipants> => {
    const resultOrErr = await client.invoke(
        new Api.channels.GetParticipants({
            channel,
            filter: new Api.ChannelParticipantsRecent(),
            limit,
            offset,
        }),
    );

    if (resultOrErr instanceof Error) {
        if (resultOrErr.message.includes("No user has")) {
            throw new Error("Channel name is incorrect or yoy haven't added homunculus to private channel");
        }

        throw resultOrErr;
    }

    if (resultOrErr instanceof ChannelParticipants) {
        if (aggregated) {
            resultOrErr.participants = resultOrErr.participants.concat(aggregated.participants);
            resultOrErr.users = resultOrErr.users.concat(aggregated.users);
            resultOrErr.chats = resultOrErr.chats.concat(aggregated.chats);
        }

        if (resultOrErr.participants.length < resultOrErr.count) {
            return getAllChannelParticipants(client, channel, resultOrErr.participants.length, limit, resultOrErr);
        }

        return resultOrErr;
    }

    throw new Error("Result in not instanceof ChannelParticipants");
};
                                                                
...
// previously defined client and other relevant stuffs above
const users: Array<UserInfo> = [];
const entity = await client.getEntity(chatId);

if (entity.className === "Channel" || entity.className === "Chat") {
   console.log("Get users for this", entity.className);
   const limit = 999999;
   const offset = 0;
   
   switch (entity.className) {
        case "Channel": {
        const members = await getAllChannelParticipants(client, entity);
        if (members instanceof ChannelParticipants) {
            const total = members.count;
                            members.participants.forEach((item) => {
                                if (item instanceof ChannelParticipant) {
                                    const user = members.users.find((u) => u.id.toString() === item.userId.toString());

                                    if (user instanceof Api.User) {
                                        users.push({
                                            id: user.id.toString(),
                                            firstName: user.firstName || "",
                                            lastName: user.lastName,
                                            username: user.username,
                                        });
                                    }
                                }
                            });

                            console.log({ total, users, totalUsers: users.length });
                        }

                        break;
                    }

                    case "Chat": {
                        const members = await client.getParticipants(entity, {
                            filter: new Api.ChannelParticipantsRecent(),
                            limit,
                            offset,
                            showTotal: true,
                        });

                        members.forEach((member) => {
                            if ("participant" in member && member.participant instanceof ChatParticipant) {
                                users.push({
                                    id: "", // member.id.toString(),
                                    firstName: member.firstName || "",
                                    lastName: member.lastName,
                                    username: "", // member.username,
                                });
                            }
                        });

                        console.log({ total: members.length, users, totalUsers: users.length });

                        break;
                    }

                    default:
                        break;
                }
            }

                                                                

Below is an example log of regular members in a group