Bus

Functions
local function	abort ()
	stop current signal
local function	emit (key, a, b, c, d, e, f)
	send unique event
local function	trigger (key)
	sender event function
local function	listen (key, handler_func)
	subscribe event

Detailed Description

Warning

This is an advanced API!
only for advanced programmers, You might be lost if you are a beginner.

You can get inspired by some explanations about how the event bus works in the JavaScript framework called Vue, it is very similar, but there is only 1 global bus that the engine itself uses to work.

Event Bus System

broadcasts some event to all nodes.

• Node 2

  std.bus.emit('say', 'ola mundo')

• Node 1 / Node 3

  std.bus.listen('say', function(msg) print(msg) end)

Event Callbacks (Deep Overview)

The event system is also used to control events from the engine itself, where the core triggers an action and it is propagated to the internal modules, and to the game and its components (nodes).

• Love2d

  function love.load()
      love.draw = std.bus.trigger('draw')
  end

• Module 1 / Module 2

  function draw(std)
  end
   
  function install(std)
      std.bus.listen_std('draw', draw)
  end

• Node 1

  return {
      meta = {
          title = 'World'
      },
      callbacks = {
          draw = function(std) end
      }
  }

• Node 2

  return {
      meta = {
          title = 'Player'
      },
      callbacks = {
          load = function(std)
              std.bus.listen_std_data('draw', function() end)
          end,
          draw = function(std) end
      }
  }

Function Documentation

abort()

local function abort

(

)

This interrupts the signal to the next nodes, this also applies to the engine itself and prevents lifecycle events.

Note

reckless use can lead to bad behavior.

Example

local function quit(std, game)
    std.bus.abort()
end

emit()

local function emit	(	key	,
		a	,
		b	,
		c	,
		d	,
		e	,
		f	)

broadcast message for all nodes.

Alternatives

• std.bus.emit_next queue to be sent in the next frame instead of immediately. but it doesn't work for draw event.

Joke

Yes, abcdef is faster to implement and execute. If you need more parameters than that, the problem is in your code.
In fact, love2d also does the same thing.

• https://love2d.org/wiki/love.event

Example

std.bus.emit('on_shoot', x1, y1, x2, y2)

listen()

local function listen	(	key	,
		handler_func	)

Alternatives

• std.bus.listen_std receive message after std
• std.bus.listen_std_data receive message after std and data
• std.bus.listen_std_engine receive message after std and engine
• std.bus.listen_all receive message without key topic, because applies to all events.

Example

std.bus.listen('player_death', function()
    print('game over!')
end)

trigger()

local function trigger

(

key

)

Example

love.filedropped = std.bus.trigger('file_dropped')