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How to create a new event handler in apps-engine repo?

How to create a new event handler in apps-engine repo?

Here, we put LivechatRoomClosed event as an example:

Apps-engine side

  1. Update the AppMethod enum which is under the definition/metadata directory. We will add a new method EXECUTELIVECHATROOMCLOSEDHANDLER:
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// Livechat
EXECUTE_LIVECHAT_ROOM_CLOSED_HANDLER = 'executeLivechatRoomClosedHandler',
...
  1. Also we need to update the AppInterface enum which is under the server/compiler/AppImplements directory:
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// Livechat
ILivechatRoomClosedHander = 'ILivechatRoomClosedHander',
...
  1. Create an interface called ILivechatRoomClosedHander.ts under the definition/livechat, its content can be similar to this:
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import { IHttp, IPersistence, IRead } from '../accessors';
import { AppMethod } from '../metadata';
import { ILivechatRoom } from './ILivechatRoom';

/**
 * Handler called after a livechat room is closed.
 */
export interface ILivechatRoomClosedHander {
    /**
     * Method called *after* a livechat room is closed.
     *
     * @param livechatRoom The livechat room which is closed.
     * @param read An accessor to the environment
     * @param http An accessor to the outside world
     * @param persistence An accessor to the App's persistence
     */
    [AppMethod.EXECUTE_LIVECHAT_ROOM_CLOSED_HANDLER](data: ILivechatRoom, read: IRead, http: IHttp, persistence: IPersistence): Promise<void>;
}

  1. Edit AppListenerManager which is under the server/manager directory:

    • Add a new case into executeListener method:

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    ...
    // Livechat
    case AppInterface.ILivechatRoomClosedHander:
        this.executeLivechatRoomClosed(data as ILivechatRoom);
        return;
    ...

    • Add executeLivechatRoomClosed method to resolve the events:

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    private async executeLivechatRoomClosed(data: ILivechatRoom): Promise<void> {
        const cfLivechatRoom = Utilities.deepCloneAndFreeze(data);

        for (const appId of this.listeners.get(AppInterface.ILivechatRoomClosedHander)) {
            const app = this.manager.getOneById(appId);

            if (!app.hasMethod(AppMethod.EXECUTE_LIVECHAT_ROOM_CLOSED_HANDLER)) {
                continue;
            }

            await app.call(AppMethod.EXECUTE_LIVECHAT_ROOM_CLOSED_HANDLER,
                cfLivechatRoom,
                this.am.getReader(appId),
                this.am.getHttp(appId),
                this.am.getPersistence(appId),
            );
        }
    }