diff options
| -rw-r--r-- | util/template.lua | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/util/template.lua b/util/template.lua new file mode 100644 index 00000000..c143a216 --- /dev/null +++ b/util/template.lua @@ -0,0 +1,112 @@ + +local t_insert = table.insert; +local st = require "util.stanza"; +local lxp = require "lxp"; +local setmetatable = setmetatable; +local pairs = pairs; +local error = error; +local s_gsub = string.gsub; + +local print = print; + +module("template") + +local function process_stanza(stanza, ops) + -- process attrs + for key, val in pairs(stanza.attr) do + if val:match("{[^}]*}") then + t_insert(ops, {stanza.attr, key, val}); + end + end + -- process children + local i = 1; + while i <= #stanza do + local child = stanza[i]; + if child.name then + process_stanza(child, ops); + elseif child:match("{[^}]*}") then -- text + t_insert(ops, {stanza, i, child}); + end + i = i + 1; + end +end + +local parse_xml = (function() + local ns_prefixes = { + ["http://www.w3.org/XML/1998/namespace"] = "xml"; + }; + local ns_separator = "\1"; + local ns_pattern = "^([^"..ns_separator.."]*)"..ns_separator.."?(.*)$"; + return function(xml) + local handler = {}; + local stanza = st.stanza("root"); + function handler:StartElement(tagname, attr) + local curr_ns,name = tagname:match(ns_pattern); + if name == "" then + curr_ns, name = "", curr_ns; + end + if curr_ns ~= "" then + attr.xmlns = curr_ns; + end + for i=1,#attr do + local k = attr[i]; + attr[i] = nil; + local ns, nm = k:match(ns_pattern); + if nm ~= "" then + ns = ns_prefixes[ns]; + if ns then + attr[ns..":"..nm] = attr[k]; + attr[k] = nil; + end + end + end + stanza:tag(name, attr); + end + function handler:CharacterData(data) + data = data:gsub("^%s*", ""):gsub("%s*$", ""); + stanza:text(data); + end + function handler:EndElement(tagname) + stanza:up(); + end + local parser = lxp.new(handler, "\1"); + local ok, err, line, col = parser:parse(xml); + if ok then ok, err, line, col = parser:parse(); end + --parser:close(); + if ok then + return stanza.tags[1]; + else + return ok, err.." (line "..line..", col "..col..")"; + end + end; +end)(); + +local function create_template(text) + local stanza, err = parse_xml(text); + if not stanza then error(err); end + local ops = {}; + process_stanza(stanza, ops); + ops.stanza = stanza; + + local template = {}; + function template.apply(data) + local newops = st.clone(ops); + for i=1,#newops do + local op = newops[i]; + local t, k, v = op[1], op[2], op[3]; + t[k] = s_gsub(v, "{([^}]*)}", data); + end + return newops.stanza; + end + return template; +end + +local templates = setmetatable({}, { __mode = 'k' }); +return function(text) + local template = templates[text]; + if not template then + template = create_template(text); + templates[text] = template; + end + return template; +end; |