How to get the string value from a hash("string")

Questions
11

Based on this button implementation:

I want to make button implementation that behave like 2 sprite when pressed and not

And for implement this, then I have 1 node on .gui with not-pressed flipbook/animation or texture(?) in component, called “button_red”.
So, when it clicked, it will change to “button_red2”, but since I have no idea to return that hash into string because I get_texture from that node, then im doing this:

-- button.lua
function Button.new(context, node_name, type, handler)
…
if self.button_type == SPRITE_TYPE then
	local texture = gui.get_flipbook(self.node)
	self.texture = string.sub(tostring(texture), 8, #tostring(texture)-1)
	self.next_texture = string.sub(tostring(texture), 8, #tostring(texture)-1).."2"
...

later, I call this string value on variable to change node

-- button.lua
function Button:press()
	if self.button_type == SPRITE_TYPE then
		gui.play_flipbook(self.node, self.next_texture)
...

Sorry for long explanation, maybe its bit weird grammar, but yeah, I have no idea in the first place to make polished button on GUI, then this is why im doing it.