util/xml.lua

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