Send effects to some players only

[adngdb]

In some cases, it can be useful to restrict an effect to be seen only by a subset of players. For example, in the case of a mulligan in a card game, one player shouldn't receive the mulliganing effects of their opponent.

User story

As a developer, I want to call an effect and have it sent to only a subset of players. That means the players not in that subset should not even know about the existence of that effect or its data, as that can contain private data.

API proposition

Here's a proposition of API based on my usage of the library and the existing code:

// Definition
ctx.effects.myEffect(data, position, duration, players);

// Call example
ctx.effects.myEffect({ secret: 1 }, '>', '1', [ '0' ]);

Questions

Looking at the code, and based on my current knowledge of boardgame.io, I'm not sure how the "unconcerned players do not know about the effect" feature can be implemented. Is there an equivalent of stripSecrets for plugins / ctx?

[delucis]

Thanks @adngdb — linking your comments on Gitter too for future reference.

boardgame.io lacks a playerView/stripSecrets equivalent for plugins at the moment, which would probably be a prerequisite for this. There’s an open issue here: boardgameio/boardgame.io#671.

Some further considerations:

• playerView could solve protecting private/secret data, but would probably not address some of the issues you outlined on Gitter with overwriting unfinished effects, as game state would still be updated, just minus any private effects. Is your primary concern with secret data here?

• I’m starting to have doubts about the effect parameters given they are all basically optional. It would be annoying if you have to write out default position and duration values just to include players (or { players } to make space for other options in the future). Any thoughts here for something more elegant? Do you think a single options object might be better or is that too verbose? Could look like: { position: '>', duration: '1', players: ['0'] }.

[delucis]

Just updating here to say that boardgameio/boardgame.io#671 has been resolved and plugins can now send different state to each player, so adding some player-targeting logic should now be possible.