Support for schema evolution using substitution groups

New examples: hybrid/evolution/ignore and hybrid/evolution/passthrough.

1 files changed, 131 insertions, 0 deletions

diff --git a/examples/cxx/hybrid/evolution/ignore/driver.cxx b/examples/cxx/hybrid/evolution/ignore/driver.cxx
new file mode 100644
index 0000000..6c1c45f
--- /dev/null
+++ b/examples/cxx/hybrid/evolution/ignore/driver.cxx
@@ -0,0 +1,131 @@
+// file      : examples/cxx/hybrid/evolution/ignore/driver.cxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : not copyrighted - public domain
+
+#include <memory>   // std::auto_ptr
+#include <string>
+#include <iostream>
+
+#include "transform.hxx"
+#include "transform-pimpl.hxx"
+
+using namespace std;
+using namespace transform;
+
+// Parser substitution map callback. This callback is called when the
+// parser needs to check whether an element belongs to a substitution
+// group. We use this callback to return a special ignored type marker
+// for unknown transformations.
+//
+static bool
+parser_callback (const xml_schema::ro_string& root_ns,
+                 const xml_schema::ro_string& root_name,
+                 const xml_schema::ro_string& /*member_ns*/,
+                 const xml_schema::ro_string& member_name,
+                 const char*& type)
+{
+  // Check that the root of the substitution group is 'transformation'.
+  //
+  if (root_name == "transformation" &&
+      root_ns == "http://www.codesynthesis.com/transform")
+  {
+    // Check that the element's name has the '-transformation' suffix. This
+    // is the convention we use in our schema to minimize the chance of
+    // treating any unknown elements as a transformation.
+    //
+    //
+    string s ("-transformation");
+    string n (member_name);
+
+    if (n.size () > s.size () &&
+        string (n, n.size () - s.size (), s.size ()) == s)
+    {
+      // Set type to the special ignore marker.
+      //
+      type = "*";
+      return true;
+    }
+  }
+
+  return false;
+}
+
+int
+main (int argc, char* argv[])
+{
+  const char* input;
+
+  if (argc < 2)
+  {
+    input = "STDIN";
+    cerr << "XML file not specified, reading from STDIN" << endl;
+  }
+  else
+    input = argv[1];
+
+  try
+  {
+    // Set the substitution map callback.
+    //
+    xml_schema::parser_smap_callback (&parser_callback);
+
+    // Parse.
+    //
+    transformations_paggr transformations_p;
+
+    // The last argument to the document's constructor indicates that we
+    // are parsing polymorphic XML documents.
+    //
+    xml_schema::document_pimpl doc_p (
+      transformations_p.root_parser (),
+      transformations_p.root_namespace (),
+      transformations_p.root_name (),
+      true);
+
+    transformations_p.pre ();
+
+    if (argc < 2)
+      doc_p.parse (cin);
+    else
+      doc_p.parse (argv[1]);
+
+    auto_ptr<transformations_type> tf (transformations_p.post ());
+
+    // Print what we've got.
+    //
+    for (transformations_type::transformation_iterator i =
+           tf->transformation ().begin ();
+         i != tf->transformation ().end ();
+         ++i)
+    {
+      transformation_type& t = *i;
+
+      if (move_type* m = dynamic_cast<move_type*> (&t))
+      {
+        cout << m->name () << ": " << m->description () << endl
+             << "\tx: " << m->x () << endl
+             << "\ty: " << m->y () << endl
+             << endl;
+      }
+      else if (rotate_type* r = dynamic_cast<rotate_type*> (&t))
+      {
+        cout << r->name () << ": " << r->description () << endl
+             << "\tangle: " << r->angle () << endl
+             << endl;
+      }
+    }
+  }
+  catch (const xml_schema::parser_exception& e)
+  {
+    cerr << input << ":" << e.line () << ":" << e.column () << ": "
+         << e.text () << endl;
+    return 1;
+  }
+  catch (const std::ios_base::failure&)
+  {
+    cerr << input << ": unable to open or read/write failure" << endl;
+    return 1;
+  }
+
+  return 0;
+}