implement some basic svg rendering

1 files changed, 65 insertions, 36 deletions

diff --git a/marigold.lua b/marigold.lua
index a6223df..9daa808 100644
--- a/marigold.lua
+++ b/marigold.lua
@@ -36,27 +36,6 @@
 
 local marigold = {}
 
-marigold.get_metavars = function()
-	local vars = {
-		"AUTH_TYPE", "CONTENT_LENGTH",
-		"CONTENT_TYPE", "GATEWAY_INTERFACE",
-		"PATH_INFO", "PATH_TRANSLATED",
-		"QUERY_STRING", "REMOTE_ADDR",
-		"REMOTE_HOST", "REMOTE_IDENT",
-		"REMOTE_USER", "REQUEST_METHOD",
-		"SCRIPT_NAME", "SERVER_NAME",
-		"SERVER_PORT", "SERVER_PROTOCOL",
-		"SERVER_SOFTWARE"
-	}	
-
-	local metavars = {}
-	for _, var in ipairs(vars) do
-		metavars[string.lower(var)] = os.getenv(var)
-	end
-	return metavars
-end
-
-
 marigold.h = function(tag_type, content, tbl)
 	if type(content) == 'table' and tbl == nil then
 		tbl = content
@@ -90,7 +69,7 @@ marigold.h = function(tag_type, content, tbl)
 end
 
 
-marigold.html = function(tbl, indent_level)
+local function render_internal(tbl, indent_level)
 	indent_level = indent_level or 0
 	local indent = string.rep('\t', indent_level)
 
@@ -117,7 +96,7 @@ marigold.html = function(tbl, indent_level)
 
 	local children = ''
 	for _, child in ipairs(tbl.children) do
-		children = children .. marigold.html(child, indent_level+1) .. '\n'
+		children = children .. render_internal(child, indent_level+1) .. '\n'
 	end
 
 	return string.format('%s%s%s\n%s%s%s',
@@ -126,25 +105,75 @@ marigold.html = function(tbl, indent_level)
 		indent, close)
 end
 
-marigold.decode_percent = function(str)
-	return string.gsub(str, "%%(%x%x)", function(digits)
-		return string.char(tonumber(digits, 16))
-	end)
+marigold.render = function(tbl)
+	local str = render_internal(tbl, 0)
+	return '<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n' .. str
 end
 
-marigold.decode_query = function(str)
-	local tbl = {}
-	local cleanString = function(str)
-		return marigold.decode_percent(
-			string.gsub(str, "+", " ")
-		)
+
+-- built-in svg types
+
+local function set(tbl)
+	local s = {}
+	for _, v in ipairs(tbl) do
+		s[v] = true
 	end
+	return s
+end
 
-	for k, v in string.gmatch(str, "([^=]-)=([^&]*)&?") do
-		tbl[cleanString(k)] = cleanString(v)
+local function validate(tagname, valid, tbl)
+	local valid_set = set(valid)
+	-- inject the core svg attributes
+	valid_set.id = true
+	valid_set.tabindex = true
+	valid_set.lang = true
+	valid_set['xml:space'] = true
+	valid_set.class = true
+	valid_set.style = true
+	for k in pairs(tbl) do
+		if not valid_set[k] then return string.format(
+			"ERROR: attempted to set invalid attribute '%s' on tag of type %s",
+			k, tagname
+		) end
 	end
+	return nil
+end
+
+local function maketag(tag, content, tbl, valid)
+	local t = marigold.h(tag, content, tbl)
+	local err = validate(tag, valid, t.attributes)
+	if err then return nil, err end
+	return t, nil
+end
 
-	return tbl
+
+marigold.svg = function(tbl)
+	local tbl = tbl or {}
+	tbl.xmlns = 'http://www.w3.org/2000/svg'
+	local tag, err = maketag('svg', '', tbl, { 'xmlns', 'viewBox', 'width', 'height' })
+	if err then error(err) end
+	return tag
 end
 
+
+marigold.g = function(tbl)
+	local tbl = tbl or {}
+	local tag, err = maketag('g', '', tbl, { 'transform' })
+	if err then error(err) end
+	return tag
+end
+
+
+marigold.rect = function(tbl)
+	local tag, err = maketag('rect', '', tbl, { 'x', 'y', 'width', 'height', 'rx', 'ry', 'transform', })
+	if err then error(err) end
+	return tag
+end
+
+
+marigold.text = function(tbl)
+end
+
+
+
 return marigold