Context in Telegram Bot Implementation

Overview

Our Telegram bot implementation is built on grammY, a powerful framework for Telegram bots. We leverage grammY's context system and extend it with our own functionality to provide seamless integration with our services.

grammY Context

grammY's Context object is a fundamental part of the framework. It provides access to information about messages and allows performing actions in response.

For comprehensive documentation about the original context implementation, please refer to the official grammY documentation on Context.

The original Context provides: - Access to message information via ctx.message, ctx.msg, etc. - Methods to respond to users via ctx.reply, ctx.replyWithPhoto, etc. - Access to the Bot API via ctx.api - And much more...

Our Extended Context

We've extended the grammY Context to integrate with our NestKit ecosystem by incorporating our ServiceMethodContext. This extension enables:

1. User Authentication: Access to the current authenticated user via ctx.user
2. Permission Management: Utilizing isGranted and validateAccess methods
3. Request Tracking: Via requestId for logging and debugging

Example Usage

// In a command handler
async run(ctx: GrammyContext): Promise<void> {
  // Access the authenticated user
  if (!ctx.isGuest()) {
    const fullName = ctx.user.fullName;
    await ctx.reply(`Hello, ${fullName}!`);
    
    // Check permissions
    if (ctx.isGranted('ugi:core:documents:get')) {
      // Perform admin actions
    }
  } else {
    // Handle guest users
    await ctx.conversation.enter(OnboardingConversation.name);
  }
}

Guest vs Authenticated Users

Our context extension provides the isGuest() method to easily determine if the current user is authenticated:

if (ctx.isGuest()) {
  // User is not authenticated
  await ctx.conversation.enter(OnboardingConversation.name);
} else {
  // User is authenticated, we can access ctx.user
  await ctx.reply(`Welcome back, ${ctx.user.fullName}!`);
}

Using Context with Services

One of the key benefits of our extended context is the ability to pass it directly to service methods:

// In a command handler or middleware
await this.userService.update(opts, ctx);

Conclusion

By extending the grammY Context with our ServiceMethodContext, we've created a seamless bridge between the Telegram bot and our application services. This allows for consistent authentication, permission checking, and logging across both our API and bot interfaces.