implement some basic svg rendering

2 files changed, 103 insertions, 104 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
diff --git a/test.lua b/test.lua
index e359c7e..47c7fed 100755
--- a/test.lua
+++ b/test.lua
@@ -1,6 +1,6 @@
-#!/usr/bin/lua
+#!/usr/bin/env lua5.1
 
-local marigold = require 'marigold'
+local svg = require 'marigold'
 
 function test(description, func)
 	io.write(description .. ': ')
@@ -15,45 +15,8 @@ function test(description, func)
 end
 
 
-test("marigold.get_metavars correctly calls os.getenv", function()
-	-- mock os.getenv
-	local old_getenv = os.getenv
-	local env_tbl = {
-		AUTH_TYPE = 'some auth type',
-		CONTENT_LENGTH = 'a zillion',
-		GATEWAY_INTERFACE = 'idk, something',
-		PATH_INFO = 'youll see, its a secret',
-		PATH_TRANSLATED = 'i told you its a secret!',
-		QUERY_STRING = 'which string do you want?',
-		REMOTE_ADDR = 'probably somewhere in nunavut',
-		REMOTE_HOST = 'woah wait are we talking about parasites?',
-		REMOTE_IDENT = 'are you a cop?',
-		REMOTE_USER = 'seriously, you have to tell me if you are',
-		REQUEST_METHOD = 'uhh, to do what?',
-		SCRIPT_NAME = 'pretty sure this is hamlet',
-		SERVER_NAME = 'this isnt a restaurant',
-		SERVER_PORT = 'what, like a ship?',
-		SERVER_PROTOCOL = 'no really, not a restaurant',
-		SERVER_SOFTWARE = 'not familiar with that dish...',
-	}
-	os.getenv = function(varname) return env_tbl[varname] end
-
-	-- actually call the function
-	metavars = marigold.get_metavars()
-
-	assert(type(metavars) == 'table')
-	for k, v in pairs(env_tbl) do
-		assert(metavars[string.lower(k)])
-		assert(metavars[string.lower(k)] == env_tbl[k])
-	end
-
-	-- restore os.getenv
-	os.getenv = old_getenv
-end)
-
-
-test("marigold.h produces a correct basic tag", function()
-	local h = marigold.h
+test("svg.h produces a correct basic tag", function()
+	local h = svg.h
 	local h1 = h('h1', 'hello, world!')
 	assert(type(h1) == 'table')
 	assert(h1.tag == 'h1')
@@ -66,8 +29,8 @@ test("marigold.h produces a correct basic tag", function()
 end)
 
 
-test("marigold.h correctly adds children", function()
-	local h = marigold.h
+test("svg.h correctly adds children", function()
+	local h = svg.h
 	local div = h('div', "some stuff", {
 		h('p', "the first paragraph"),
 		h('p', "the second paragraph"),
@@ -87,8 +50,8 @@ test("marigold.h correctly adds children", function()
 end)
 
 
-test("marigold.h correctly ignores missing content", function()
-	local h = marigold.h
+test("svg.h correctly ignores missing content", function()
+	local h = svg.h
 	local div = h('div', {
 		h('p', "the first paragraph"),
 		h('p', "the second paragraph"),
@@ -108,8 +71,8 @@ test("marigold.h correctly ignores missing content", function()
 end)
 
 
-test("marigold.h correctly sets attributes and children", function()
-	local h = marigold.h
+test("svg.h correctly sets attributes and children", function()
+	local h = svg.h
 	local div = h('div', {
 		id="root", class="blinking bold",
 		h('p', "the first paragraph"),
@@ -130,24 +93,24 @@ test("marigold.h correctly sets attributes and children", function()
 end)
 
 
-test("marigold.html correctly renders basic html table", function()
+test("svg.render correctly renders basic render table", function()
 	local tbl = { tag='p', content='some paragraph', attributes={}, children={}}
-	local html = marigold.html(tbl)
-	assert(html == '<p>some paragraph</p>')
+	local render = svg.render(tbl)
+	assert(render == '<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n<p>some paragraph</p>')
 end)
 
 
-test("marigold.html correctly renders tag attributes", function()
+test("svg.render correctly renders tag attributes", function()
 	local tbl = { 
 		tag='p', content='some paragraph', 
 		attributes={ id='p1', class='blinking bold' }, 
 		children={}}
-	local html = marigold.html(tbl)
-	assert(html == '<p class="blinking bold" id="p1">some paragraph</p>')
+	local render = svg.render(tbl)
+	assert(render == '<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n<p class="blinking bold" id="p1">some paragraph</p>')
 end)
 
 
-test("marigold.html correctly renders children", function()
+test("svg.render correctly renders children", function()
 	local tbl = {
 		tag = 'div', content='', attributes = {id="root"},
 		children = {
@@ -156,27 +119,34 @@ test("marigold.html correctly renders children", function()
 		}
 	}
 
-	local html = marigold.html(tbl)
-	assert(html == [[<div id="root">
+	local render = svg.render(tbl)
+	assert(render == [[<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<div id="root">
 	<p class="bold">p1</p>
 	<p>p2</p>
 </div>]])
 end)
 
 
-test("marigold.decode_percent correctly decodes percent-encoded strings", function()
-	local str = '%20%21%23%24%25%26%27%28%29%2A%2B%2C%2F%3A%3B%3D%3F%40%5B%5D'
-	assert(marigold.decode_percent(str) == " !#$%&'()*+,/:;=?@[]")
-	assert(marigold.decode_percent('%25+%2b') == '%++')
+
+
+test("svg.svg correctly has xmlns attribute set", function()
+	local tbl = svg.svg()
+	assert(tbl.tag == 'svg')
+	assert(tbl.content == '')
+	assert(tbl.attributes.xmlns == 'http://www.w3.org/2000/svg')
+	assert(#tbl.children == 0)
 end)
 
 
-test("marigold.decode_query correctly obtains data", function()
-	local tbl
-	tbl = marigold.decode_query('')
-	tbl = marigold.decode_query('name=john')
-	assert(tbl.name == 'john')
-	tbl = marigold.decode_query('string=hello%2C+world%21&name=jane')
-	assert(tbl.string == 'hello, world!')
-	assert(tbl.name == 'jane')
+test("svg.g can set transform attribute", function()
+	local tbl = svg.g{
+		transform = "rotate(45deg)",
+		svg.g(),
+		svg.g(),
+	}
+	assert(tbl.tag == 'g')
+	assert(tbl.content == '')
+	assert(tbl.attributes.transform == 'rotate(45deg)')
+	assert(#tbl.children == 2)
 end)