Dynamic scenes from backend

[roviks]

Hello @IlyaSemenov, I want to store all the scenes in the backend, there should be features for create, edit and delete a scene from the admin panel. Any ideas or examples how to do this? Can you help with it?

[IlyaSemenov]

You can use bot.lazy to inject custom set of scenes on each request:

type BotContext = Context &
  SessionFlavor<ScenesSessionData> &
  ScenesFlavor & {
    scenes_composer: ScenesComposer<any> // typing grammy always gives headaches, so use any for now
  }

// replace this:
bot.use(scenes.manager())
// with:
bot.lazy(ctx => {
  const scenes = new ScenesComposer<BotContext>()
  // fill from the database
  ctx.scenes_composer = scenes
  return scenes.manager()
})

// replace this:
bot.use(scenes)
// with:
bot.lazy(ctx => ctx.scenes_composer)

Perhaps, the manager could store a link to its composer to reduce this boilerplate, but the generic approach will be the same.

[IlyaSemenov]

In grammy-scenes 10.2, you can now do:

// Inject ctx.scenes
bot.lazy((ctx) => {
  const scenes = new ScenesComposer<BotContext>()
  // Populate scenes in runtime with scenes.scene(...)
  return scenes.manager()
})

bot.command("start", async (ctx) => {
  // Assuming you will always have the main scene:
  await ctx.scenes.enter("main")
})

// Actually run scenes
bot.lazy((ctx) => ctx.scenes.composer)

bot.start()