Generates layer and tag data (a la the --data cli option) for an aseprite file, but includes proper layer hierarchy information as well as tag colors.

aseprite_layer_and_tag_data.lua

local spr = app.activeSprite
if not spr then return app.alert "No active sprite" end

local function color_byte_to_string( col )
	local hex = ''

	while(col > 0)do
		local index = math.fmod(col, 16) + 1
		col = math.floor(col / 16)
		hex = string.sub('0123456789abcdef', index, index) .. hex			
	end

	if(string.len(hex) == 0)then
		hex = '00'
	elseif(string.len(hex) == 1)then
		hex = '0' .. hex
	end

	return hex
end

local function color_to_string( color )
	local hexadecimal = '#'
	
	hexadecimal = hexadecimal .. color_byte_to_string( color.red )
	hexadecimal = hexadecimal .. color_byte_to_string( color.green )
	hexadecimal = hexadecimal .. color_byte_to_string( color.blue )
	hexadecimal = hexadecimal .. color_byte_to_string( color.alpha )

	return hexadecimal
end

local blend_mode_strings = {
	[ BlendMode.NORMAL ] = "normal",
	[ BlendMode.MULTIPLY ] = "multiply",
	[ BlendMode.SCREEN ] = "screen",
	[ BlendMode.OVERLAY ] = "overlay",
	[ BlendMode.DARKEN ] = "darken",
	[ BlendMode.LIGHTEN ] = "lighten",
	[ BlendMode.COLOR_DODGE ] = "color_dodge",
	[ BlendMode.COLOR_BURN ] = "color_burn",
	[ BlendMode.HARD_LIGHT ] = "hard_light",
	[ BlendMode.SOFT_LIGHT ] = "soft_light",
	[ BlendMode.DIFFERENCE ] = "difference",
	[ BlendMode.EXCLUSION ] = "exclusion",
	[ BlendMode.HSL_HUE ] = "hsl_hue",
	[ BlendMode.HSL_SATURATION ] = "hsl_saturation",
	[ BlendMode.HSL_COLOR ] = "hsl_color",
	[ BlendMode.HSL_LUMINOSITY ] = "hsl_luminosity",
	[ BlendMode.ADDITION ] = "addition",
	[ BlendMode.SUBTRACT ] = "subtract",
	[ BlendMode.DIVIDE ] = "divide",
    default = "unknown"
}

local anidir_strings = {
	[ AniDir.FORWARD ] = "forward",
	[ AniDir.REVERSE ] = "reverse",
	[ AniDir.PING_PONG ] = "pingpong",
    default = "unknown"
}

local function blend_mode_to_string( blendMode )
	local val = blend_mode_strings[ blendMode ]
	if val then
		return val
	else
		return val[ "default" ]
	end
end

local function anidir_to_string( anidir )
	local val = anidir_strings[ anidir ]
	if val then
		return val
	else
		return val[ "default" ]
	end
end

local indent = ''
local function print_layers( layers )
	local old_indent = indent
	indent = indent .. '  '
	io.write "[\n"
	local first = true
	for _,l in ipairs( layers ) do
		if first then first = false else io.write(',\n') end

		local blendMode = l.blendMode
		if blendMode == nil then 
			blendMode = ""
		else
			blendMode = '"blendMode": "' .. blend_mode_to_string( blendMode ) .. '", '
		end

		local color = l.color
		if color == nil then
			color = ""
		else
			if color.alpha == 0 then
				color = ""
			else
				color = '"color": "' .. color_to_string( color ) .. '", '
			end
		end

		local opacity = l.opacity
		if opacity == nil then
			opacity = ""
		else
			opacity = '"opacity": ' .. opacity .. ', '
		end

		io.write( indent .. '{ "visible": ' .. ( l.isVisible and "true" or "false" ) .. ', "userData": "' .. l.data .. '", ' .. blendMode .. color .. opacity .. '"name": "' .. l.name.. '"' )
		if l.isGroup then

			io.write( ', "layers": ' )
			print_layers( l.layers )

			io.write( indent .. '}' )
		else
			io.write( ' }' )
		end
	end
	io.write( "\n" )
	indent = old_indent
	io.write( indent .. "]\n" )
end

local function print_tags( tags )
	local old_indent = indent
	indent = indent .. '  '
	io.write "[\n"
	local first = true
	for _,s in ipairs( tags ) do
		if first then first = false else io.write(',\n') end

		local direction = s.aniDir
		if direction == nil then
			direction = ""
		else
			direction = anidir_to_string( direction )
		end

		local color = s.color
		if color == nil then
			color = ""
		else
			if color.alpha == 0 then
				color = ""
			else
				color = '"color": "' .. color_to_string( color ) .. '", '
			end
		end

		local fromFrame = s.fromFrame
		if type(fromFrame) ~= "number" then -- support new Frame construct or legacy
			fromFrame = fromFrame.frameNumber
		end

		local toFrame = s.toFrame
		if type(toFrame) ~= "number" then -- support new Frame construct or legacy
			toFrame = toFrame.frameNumber
		end

		io.write( indent .. '{ "name": "' .. s.name.. '", "from": ' .. fromFrame .. ', "to": ' .. toFrame .. ', ' .. color .. '"direction": "' .. direction .. '" }' )
	end
	io.write( "\n" )
	indent = old_indent
	io.write( indent .. "]\n" )
end

io.write( '{' )
io.write( '"frameTags":' )
print_tags( spr.tags )
io.write( ',' )
io.write( '"layers":' )
print_layers( spr.layers )
io.write( '}' )