local xml_replacements = {
{ "&", "&" },
{ "<", "<" },
{ ">", ">" },
}
local attribute_replacements = {
{ '"', '\\"' },
}
local function generic_escape(str, replacements)
local _, r
for _, r in pairs(replacements) do
str = string.gsub(str, r[1], r[2])
end
return str
end
local function xml_escape(str)
return generic_escape(str, xml_replacements)
end
local function attribute_escape(str)
return generic_escape(str, attribute_replacements)
end
local function process_comment(xm, a)
return {
istop = true,
nodes = {
a
},
type = "comment",
}
end
local function process_lf(xm)
return {
istop = true,
type = "lf",
}
end
local function burrow(t)
local k, v
if type(t) ~= "table" then return end
if type(t.istop) ~= "boolean" then return end
t.istop = nil
end
local function clean_tops(t)
local k, v
for k, v in pairs(t) do
if not v.istop then
t[k] = nil
end
end
end
local function process_tag(xm, key, a)
local ret, attrs, nodes, has_nodes, has_attrs, k, v, b = { istop = true, key = key }, {}, {}, false, false
if type(a) == "table" then
for k, v in ipairs(a) do
if type(v) == "table" then
burrow(v)
has_nodes = true
table.insert(nodes, v)
elseif type(v) == "string" then
has_nodes = true
table.insert(nodes, xml_escape(v))
else
error "Unsupported argument type."
end
end
for k, v in pairs(a) do
if (type(k) == "string") then
has_attrs = true
attrs[k] = attribute_escape(xml_escape(v))
end
end
elseif type(a) == "string" then
has_nodes = true
table.insert(nodes, xml_escape(a))
end
if (has_nodes) then ret.nodes = nodes end
if (has_attrs) then ret.attrs = attrs end
table.insert(xm.tops, ret)
clean_tops(xm.tops)
return ret
end
local function render_attrs(t)
local r, k, v
if type(t) ~= "table" then return "" end
for k, v in pairs(t) do
r = r .. " " .. k .. '="' .. v .. '"'
end
return r
end
local function do_render_r(v)
local middle, i, n = ""
if v.type == "comment" then
return ""
elseif v.type == "lf" then
return "\n"
elseif type(v.key) == "string" then
if type(v.nodes) == "table" then
for i, n in ipairs(v.nodes) do
if type(n) == "string" then
middle = middle .. n
elseif type(n) == "table" then
middle = middle .. do_render_r(n)
end
end
return "<" .. v.key .. render_attrs(v.attrs) .. ">" .. middle .. ""
else
return "<" .. v.key .. render_attrs(v.attrs) .. " />"
end
else
error "Inconsistancy in the XML structure."
end
return ""
end
local function do_render(xm)
local r, i, n = ""
for i, n in pairs(xm.tops) do
r = r .. do_render_r(n)
end
return xm.doctype .. "\n" .. r
end
local xmlmarkup_metatable = {
__index = function(xm, key)
local k = key
return function(xm, a) return process_tag(xm, k, a) end
end
}
function NewXmlMarkup()
local r = {
comment = process_comment,
lf = process_lf,
tops = {},
render = do_render,
doctype = '',
}
setmetatable(r, xmlmarkup_metatable)
return r
end
--[[ example of use:
-- result is:
-- TestNormal test
Bold test.
xm = NewXmlMarkup()
xm:html {
xm:head {
xm:title "Test"
},
xm:body {
bgcolor = "#ffeedd",
"Normal test",
xm:br(),
xm:b "Bold test.",
xm:comment "Hi there...",
}
}
print(xm:render())
]]--