xsd/examples/cxx/parser/polyroot/driver.cxx


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

// file      : examples/cxx/parser/polyroot/driver.cxx
// copyright : not copyrighted - public domain

#include <map>
#include <string>
#include <iostream>

#include "supermen-pimpl.hxx"

using std::cerr;
using std::endl;
using xml_schema::ro_string;

// Customize the xml_schema::document object to handle polymorphic
// root element. For more information see the multiroot example.
//
class document: public xml_schema::document
{
public:
  document (const xml_schema::parser_map& parser_map)
      : xml_schema::document (true), // Indicate polymorphic parsing.
        parser_map_ (parser_map)
  {
  }

protected:
  // This function is called to obtain the root element type parser.
  // If the returned pointer is 0 then the whole document content
  // is ignored. The type argument contains the XML Schema type
  // if xsi:type attribute was specified for this element and 0
  // otherwise.
  //
  virtual xml_schema::parser_base*
  start_root_element (const ro_string& ns,
                      const ro_string& name,
                      const ro_string* type)
  {
    if (name != "person" || !ns.empty ())
      return 0;

    xml_schema::parser_base* base;

    // Search the parser map.
    //
    if (type == 0)
    {
      // No xsi:type. Static type should be used.
      //
      ro_string st (person_pskel::_static_type ());
      base = parser_map_.find (st);
    }
    else
    {
      base = parser_map_.find (*type);
    }

    if (base != 0)
    {
      parser_used_ = dynamic_cast<person_pskel*> (base);
      parser_used_->pre ();
    }
    else
      parser_used_ = 0; // No parser for this type.

    return parser_used_;
  }

  // This function is called to indicate the completion of document
  // parsing. The parser argument contains the pointer returned by
  // start_root_element.
  //
  virtual void
  end_root_element (const ro_string& /* ns */,
                    const ro_string& /* name */,
                    xml_schema::parser_base* /* parser */)
  {
    // Instead of caching the current parser in parser_used_, we
    // could also dynamic_cast the parser argument to the person_pskel
    // type.
    //
    if (parser_used_)
      parser_used_->post_person ();
  }


private:
  const xml_schema::parser_map& parser_map_;
  person_pskel* parser_used_;
};

int
main (int argc, char* argv[])
{
  if (argc != 2)
  {
    cerr << "usage: " << argv[0] << " instance.xml" << endl;
    return 1;
  }

  try
  {
    // Construct the parser.
    //
    xml_schema::string_pimpl string_p;
    xml_schema::boolean_pimpl boolean_p;
    xml_schema::unsigned_int_pimpl unsigned_int_p;

    person_pimpl person_p;
    superman_pimpl superman_p;
    batman_pimpl batman_p;

    person_p.parsers (string_p);
    superman_p.parsers (string_p, boolean_p);
    batman_p.parsers (string_p, boolean_p, unsigned_int_p);

    // Parse the XML document.
    //
    xml_schema::parser_map_impl person_map;

    person_map.insert (person_p);
    person_map.insert (superman_p);
    person_map.insert (batman_p);

    document doc_p (person_map);

    doc_p.parse (argv[1]);
  }
  catch (const xml_schema::exception& e)
  {
    cerr << e << endl;
    return 1;
  }
  catch (const std::ios_base::failure&)
  {
    cerr << argv[1] << ": unable to open or read failure" << endl;
    return 1;
  }
}