templates.lua

module("templates", package.seeall)

local tpl = {};

local tpl_mt = { __index = tpl };

local tplutil = {};

local tplutil_mt = { __index = tplutil };

function tpl:saverender(fn, vars)

	local f, err = io.open(fn, "w+");

	if not f then return f,err; end

	f:write(self:render(vars));

	f:close();

	return true

end

function tpl:render(vars)

	local tpl = self.tpl or self.file:read("*a");

	self.tpl = tpl;

	if not vars then return tpl; end

	return (tpl:gsub("%b{}", 	function (cap)

						local v = cap:match("^%{%{%s*(.-)%s*%}%}*$")

						if not v then return cap; end

						local chunk, err = loadstring("return "..v);

						if not chunk then

							chunk, err = loadstring(v);

							if not chunk then error(err); end

						end

						setfenv(chunk, vars);

						local ok, ret = pcall(chunk);

						if not ok then error(ret); end

						do return ret or ""; end

						local v = cap:match("^%{%{%s*([%w_%.]+)%s*%}%}*$")

						if v then

							local _vars = vars;

							local ret, subs = v:gsub("(%w+)%.", function (var) if _vars then _vars = _vars[var]; end end);

							if _vars and _vars ~= vars then return _vars[v:match("%w+$")] or cap; end

							return vars[v] or cap;

						end

						local v = cap:match("^%{*[%w_]+%(.*%}*$");

						if v then

							local chunk, err = loadstring("return "..v:sub(2,-2));

							if not chunk then error("error in template: "..tostring(err)); end

							setfenv(chunk, setmetatable(vars, tplutil_mt));

							local success, ret = pcall(chunk);

							if success then

								return ret;

							else

								error("error in template: "..ret);

							end

						end

					end));

end

-- -- -- --

local function escape(s) return s; end

function tplutil.kvlist(t)

	if #t > 0 then

		-- Assume an array

		if type(t[1]) == "table" then

			-- Assume a table of tables

		else

			-- Assume a straight list

		end

	else

		-- assume a k->v list

		local b = { "<table>" };

	end

end

function tplutil.ulist(t)

	-- assume a list/array

	local b = { "<ul>\n" };

	for _, v in ipairs(t) do

		table.insert(b, "   <li>"..escape(v).."</li>\n");

	end

	table.insert(b, "</ul>\n");

	return table.concat(b);

end

function init(file)

	local f, err = io.open(file);

	if not f then return nil, "Couldn't open template file: "..err; end

	return setmetatable({ file = f }, tpl_mt);

end

function load(template)

	return setmetatable({ tpl = template }, tpl_mt);

end