create-empirica-app/templates/basic/server/callbacks.js

Create Empirica apps easily.

import Empirica from "meteor/empirica:core";

// onGameStart is triggered opnce per game before the game starts, and before
// the first onRoundStart. It receives the game and list of all the players in
// the game.
Empirica.onGameStart(game => {});

// onRoundStart is triggered before each round starts, and before onStageStart.
// It receives the same options as onGameStart, and the round that is starting.
Empirica.onRoundStart((game, round) => {});

// onStageStart is triggered before each stage starts.
// It receives the same options as onRoundStart, and the stage that is starting.
Empirica.onStageStart((game, round, stage) => {});

// onStageEnd is triggered after each stage.
// It receives the same options as onRoundEnd, and the stage that just ended.
Empirica.onStageEnd((game, round, stage) => {});

// onRoundEnd is triggered after each round.
// It receives the same options as onGameEnd, and the round that just ended.
Empirica.onRoundEnd((game, round) => {
  game.players.forEach(player => {
    const value = player.round.get("value") || 0;
    const prevScore = player.get("score") || 0;
    player.set("score", prevScore + value);
  });
});

// onGameEnd is triggered when the game ends.
// It receives the same options as onGameStart.
Empirica.onGameEnd(game => {});

// ===========================================================================
// => onSet, onAppend and onChange ==========================================
// ===========================================================================

// onSet, onAppend and onChange are called on every single update made by all
// players in each game, so they can rapidly become quite expensive and have
// the potential to slow down the app. Use wisely.
//
// It is very useful to be able to react to each update a user makes. Try
// nontheless to limit the amount of computations and database saves (.set)
// done in these callbacks. You can also try to limit the amount of calls to
// set() and append() you make (avoid calling them on a continuous drag of a
// slider for example) and inside these callbacks use the `key` argument at the
// very beginning of the callback to filter out which keys your need to run
// logic against.
//
// If you are not using these callbacks, comment them out so the system does
// not call them for nothing.

// // onSet is called when the experiment code call the .set() method
// // on games, rounds, stages, players, playerRounds or playerStages.
// Empirica.onSet((
//   game,
//   round,
//   stage,
//   player, // Player who made the change
//   target, // Object on which the change was made (eg. player.set() => player)
//   targetType, // Type of object on which the change was made (eg. player.set() => "player")
//   key, // Key of changed value (e.g. player.set("score", 1) => "score")
//   value, // New value
//   prevValue // Previous value
// ) => {
//   // // Example filtering
//   // if (key !== "value") {
//   //   return;
//   // }
// });

// // onAppend is called when the experiment code call the `.append()` method
// // on games, rounds, stages, players, playerRounds or playerStages.
// Empirica.onAppend((
//   game,
//   round,
//   stage,
//   player, // Player who made the change
//   target, // Object on which the change was made (eg. player.set() => player)
//   targetType, // Type of object on which the change was made (eg. player.set() => "player")
//   key, // Key of changed value (e.g. player.set("score", 1) => "score")
//   value, // New value
//   prevValue // Previous value
// ) => {
//   // Note: `value` is the single last value (e.g 0.2), while `prevValue` will
//   //       be an array of the previsous valued (e.g. [0.3, 0.4, 0.65]).
// });

// // onChange is called when the experiment code call the `.set()` or the
// // `.append()` method on games, rounds, stages, players, playerRounds or
// // playerStages.
// Empirica.onChange((
//   game,
//   round,
//   stage,
//   player, // Player who made the change
//   target, // Object on which the change was made (eg. player.set() => player)
//   targetType, // Type of object on which the change was made (eg. player.set() => "player")
//   key, // Key of changed value (e.g. player.set("score", 1) => "score")
//   value, // New value
//   prevValue, // Previous value
//   isAppend // True if the change was an append, false if it was a set
// ) => {
//   // `onChange` is useful to run server-side logic for any user interaction.
//   // Note the extra isAppend boolean that will allow to differenciate sets and
//   // appends.
//    Game.set("lastChangeAt", new Date().toString())
// });

// // onSubmit is called when the player submits a stage.
// Empirica.onSubmit((
//   game,
//   round,
//   stage,
//   player // Player who submitted
// ) => {
// });