util/xml.lua

   1
   2 local st = require "util.stanza";
   3 local lxp = require "lxp";
   4 local t_insert = table.insert;
   5 local t_remove = table.remove;
   6
   7 local _ENV = nil;
   8
   9 local parse_xml = (function()
  10         local ns_prefixes = {
  11                 ["http://www.w3.org/XML/1998/namespace"] = "xml";
  12         };
  13         local ns_separator = "\1";
  14         local ns_pattern = "^([^"..ns_separator.."]*)"..ns_separator.."?(.*)$";
  15         return function(xml)
  16                 --luacheck: ignore 212/self
  17                 local handler = {};
  18                 local stanza = st.stanza("root");
  19                 local namespaces = {};
  20                 local prefixes = {};
  21                 function handler:StartNamespaceDecl(prefix, url)
  22                         if prefix ~= nil then
  23                                 t_insert(namespaces, url);
  24                                 t_insert(prefixes, prefix);
  25                         end
  26                 end
  27                 function handler:EndNamespaceDecl(prefix)
  28                         if prefix ~= nil then
  29                                 -- we depend on each StartNamespaceDecl having a paired EndNamespaceDecl
  30                                 t_remove(namespaces);
  31                                 t_remove(prefixes);
  32                         end
  33                 end
  34                 function handler:StartElement(tagname, attr)
  35                         local curr_ns,name = tagname:match(ns_pattern);
  36                         if name == "" then
  37                                 curr_ns, name = "", curr_ns;
  38                         end
  39                         if curr_ns ~= "" then
  40                                 attr.xmlns = curr_ns;
  41                         end
  42                         for i=1,#attr do
  43                                 local k = attr[i];
  44                                 attr[i] = nil;
  45                                 local ns, nm = k:match(ns_pattern);
  46                                 if nm ~= "" then
  47                                         ns = ns_prefixes[ns];
  48                                         if ns then
  49                                                 attr[ns..":"..nm] = attr[k];
  50                                                 attr[k] = nil;
  51                                         end
  52                                 end
  53                         end
  54                         local n = {}
  55                         for i=1,#namespaces do
  56                                 n[prefixes[i]] = namespaces[i];
  57                         end
  58                         stanza:tag(name, attr, n);
  59                 end
  60                 function handler:CharacterData(data)
  61                         stanza:text(data);
  62                 end
  63                 function handler:EndElement()
  64                         stanza:up();
  65                 end
  66                 local parser = lxp.new(handler, "\1");
  67                 local ok, err, line, col = parser:parse(xml);
  68                 if ok then ok, err, line, col = parser:parse(); end
  69                 --parser:close();
  70                 if ok then
  71                         return stanza.tags[1];
  72                 else
  73                         return ok, err.." (line "..line..", col "..col..")";
  74                 end
  75         end;
  76 end)();
  77
  78 return {
  79         parse = parse_xml;
  80 };