Corona SDK - Next level, reset level logic

While developing games, you'll need to switch between levels and probably reset the current one, to let users another try. Here is how you can easily implement this logic to your game.

In menu.lua file (or other main file you might have) let's set a global variable that will represent current level:

curLevel = 1

Now let's create level.lua file, where we will load our level, based on currentLevel variable, and create two buttons, reset level and next level. There are many ways to manage levels, you can store tham in files in json or xml format, or have separate lua files with levels, I'll leave it up to you.

function scene:createScene( event )
	group = self.view
	--Load your level based on currentLevel variable here
	
	--define button dimensions
	local btnW, btnH = 100, 20
	
	--create next level button
	nextBtn = display.newImageRect( "next.png", btnW, btnH )
	
	--place button in center
	nextBtn:setReferencePoint( display.CenterReferencePoint )
	nextBtn.x, nextBtn.y = display.contentWidth-(btnW/2), display.contentHeight-(btnH/2)
	
	--add event
	nextBtn:addEventListener( "touch", nextLevel ) 
	group:insert( nextBtn )
	
	--create reset level button
	resetBtn = display.newImageRect( "reset.png", btnW, btnH )
	
	--put it on near next level button
	resetBtn:setReferencePoint( display.CenterReferencePoint )
	resetBtn.x, resetBtn.y = display.contentWidth-(btnW/2), (display.contentHeight-(btnH/2))+30
	
	--add event
	resetBtn:addEventListener( "touch", resetLevel ) 
	group:insert( resetBtn )
end

--next level
function nextLevel()
	--check if user is eligible to continue
	--check if it is not the last level
	currentLevel = currentLevel + 1
	storyboard.gotoScene( "reset", "fade", 250 )
	
	return true	-- indicates successful touch
end

--reset level
function resetLevel()
	-- simply go to level1.lua scene
	storyboard.gotoScene( "reset", "fade", 250 )
	
	return true	-- indicates successful touch
end

Then we need to create reset.lua file, which will handle level reseting or transition to other level:

local storyboard = require( "storyboard" )
local scene = storyboard.newScene()

-- Called when the scene's view does not exist:
function scene:createScene( event )
	local group = self.view

end

-- Called immediately after scene has moved onscreen:
function scene:enterScene( event )
	local group = self.view
	--purge level
	storyboard.purgeScene( "level" )
	--go back to level, by loading it from scratch
	storyboard.gotoScene( "level", "fade", 250 )
end

-- Called when scene is about to move offscreen:
function scene:exitScene( event )
	local group = self.view
end

-- If scene's view is removed, scene:destroyScene() will be called just prior to:
function scene:destroyScene( event )
	local group = self.view
end

-- "createScene" event is dispatched if scene's view does not exist
scene:addEventListener( "createScene", scene )

-- "enterScene" event is dispatched whenever scene transition has finished
scene:addEventListener( "enterScene", scene )

-- "exitScene" event is dispatched whenever before next scene's transition begins
scene:addEventListener( "exitScene", scene )

-- "destroyScene" event is dispatched before view is unloaded, which can be
-- automatically unloaded in low memory situations, or explicitly via a call to
-- storyboard.purgeScene() or storyboard.removeScene().
scene:addEventListener( "destroyScene", scene )

return scene

Since you are loading your level, based on global currentLevel variable, all we need to do is purge level.lua file and navigate back to it.

That's it