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util/template.lua @ 4875:f9fe28461101
MUC: Fix check for history length update.
author | Waqas Hussain <waqas20@gmail.com> |
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date | Mon, 14 May 2012 02:42:42 +0500 |
parent | 4495:c0f5c78cb817 |
child | 5214:1430c6f36621 |
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local st = require "util.stanza"; local lxp = require "lxp"; local setmetatable = setmetatable; local pairs = pairs; local ipairs = ipairs; local error = error; local loadstring = loadstring; local debug = debug; local t_remove = table.remove; module("template") 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.."?(.*)$"; return function(xml) local handler = {}; local stanza = st.stanza("root"); function handler:StartElement(tagname, attr) local curr_ns,name = tagname:match(ns_pattern); if name == "" then curr_ns, name = "", curr_ns; end if curr_ns ~= "" then attr.xmlns = curr_ns; end for i=1,#attr do local k = attr[i]; attr[i] = nil; local ns, nm = k:match(ns_pattern); if nm ~= "" then ns = ns_prefixes[ns]; if ns then attr[ns..":"..nm] = attr[k]; attr[k] = nil; end end end stanza:tag(name, attr); end function handler:CharacterData(data) stanza:text(data); end function handler:EndElement(tagname) stanza:up(); end local parser = lxp.new(handler, "\1"); local ok, err, line, col = parser:parse(xml); if ok then ok, err, line, col = parser:parse(); end --parser:close(); if ok then return stanza.tags[1]; else return ok, err.." (line "..line..", col "..col..")"; end end; end)(); local function trim_xml(stanza) for i=#stanza,1,-1 do local child = stanza[i]; if child.name then trim_xml(child); else child = child:gsub("^%s*", ""):gsub("%s*$", ""); stanza[i] = child; if child == "" then t_remove(stanza, i); end end end end local function create_string_string(str) str = ("%q"):format(str); str = str:gsub("{([^}]*)}", function(s) return '"..(data["'..s..'"]or"").."'; end); return str; end local function create_attr_string(attr, xmlns) local str = '{'; for name,value in pairs(attr) do if name ~= "xmlns" or value ~= xmlns then str = str..("[%q]=%s;"):format(name, create_string_string(value)); end end return str..'}'; end local function create_clone_string(stanza, lookup, xmlns) if not lookup[stanza] then local s = ('setmetatable({name=%q,attr=%s,tags={'):format(stanza.name, create_attr_string(stanza.attr, xmlns)); -- add tags for i,tag in ipairs(stanza.tags) do s = s..create_clone_string(tag, lookup, stanza.attr.xmlns)..";"; end s = s..'};'; -- add children for i,child in ipairs(stanza) do if child.name then s = s..create_clone_string(child, lookup, stanza.attr.xmlns)..";"; else s = s..create_string_string(child)..";" end end s = s..'}, stanza_mt)'; s = s:gsub('%.%.""', ""):gsub('([=;])""%.%.', "%1"):gsub(';"";', ";"); -- strip empty strings local n = #lookup + 1; lookup[n] = s; lookup[stanza] = "_"..n; end return lookup[stanza]; end local stanza_mt = st.stanza_mt; local function create_cloner(stanza, chunkname) local lookup = {}; local name = create_clone_string(stanza, lookup, ""); local f = "local setmetatable,stanza_mt=...;return function(data)"; for i=1,#lookup do f = f.."local _"..i.."="..lookup[i]..";"; end f = f.."return "..name..";end"; local f,err = loadstring(f, chunkname); if not f then error(err); end return f(setmetatable, stanza_mt); end local template_mt = { __tostring = function(t) return t.name end }; local function create_template(templates, text) local stanza, err = parse_xml(text); if not stanza then error(err); end trim_xml(stanza); local info = debug.getinfo(3, "Sl"); info = info and ("template(%s:%d)"):format(info.short_src:match("[^\\/]*$"), info.currentline) or "template(unknown)"; local template = setmetatable({ apply = create_cloner(stanza, info), name = info, text = text }, template_mt); templates[text] = template; return template; end local templates = setmetatable({}, { __mode = 'k', __index = create_template }); return function(text) return templates[text]; end;