lua - Bullet Fire Reset Event Corona SDK -

so im trying have enemy fire randomly, when bullet goes off screen signal enemy , allow enemy fire again. every instance of enemy can have 1 active instance of bullet @ time. far testing fire , refire implementation. function shoot called of instance of enemy following:

function enemy:shoot()     --calls bullet obj file     local bullet = require "bullet";      --movement time per space     local defaulttime = 5;      --checking if property, there active bullet instance in scene     if self.activebul ==false           --move bullet           self.bullet:trajectbullet({x=self.sprite.x,y=display.contentheight, time = defaulttime*   (display.contentheight-self.sprite.y)});            --there active bullet linked enemy           self.activebul = true;      else      end end 

all happening in trajectbullet movement implementation. im trying figure out how able let linked enemy instance know bullet off screen. im new lua , corona sdk im still getting grasp on how best process things please bear me simple outline of im looking below

--random enemy fire  --move bullet location on top of enemy(appears enemy fires)  --makes linked bullet visible  --simulates trajectory   case:* doesn't hit , goes off screen*    --hides bullet    --signals linked enemy can fire again(changing activebul false) 

couple things keep in mind, have both bullet , enemy metatables. bullet instance created same time enemy created. the enemy never creates multiple bullet instances, hides , relocates firing.

im looking insight on how should go getting work properly, advice appreciated

if know when bullet off screen, can use 2 approachs: 1. have reference enemy on bullet, can call funcion on "recicle" bullet; 2. create custom event dispatched bullet when off screen.

i stick 2), because of flexibility.

you can find more here:

• http://docs.coronalabs.com/api/type/eventlistener/dispatchevent.html
• http://docs.coronalabs.com/api/type/eventlistener/addeventlistener.html

---

-- 1) function enemy:shoot()   local bullet = require "bullet";   bullet.owner = self;   -- same previous code end;  function enemy:canshootagain()   self.activebul = false; end;  -- when want enemy shoot again, call canshootagain bullet bullet.owner:canshootagain(); 

---

-- 2) function enemy:shoot()   local bullet = require "bullet";   bullet.owner = self;   -- same previous code end;  function enemy:canshootagain()   self.activebul = false; end;  -- when want enemy shoot again, call canshootagain bullet bullet.owner:dispatchevent({name = 'canshootagain'});  -- add end of enemy construction enemy:addeventlistener('canshootagain', enemy);