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// file : examples/cxx/parser/multiroot/driver.cxx
// author : Boris Kolpackov <boris@codesynthesis.com>
// copyright : not copyrighted - public domain
#include <memory> // std::auto_ptr
#include <iostream>
#include "protocol.hxx"
#include "protocol-pskel.hxx" // Get the configuration macros (XSDE_*).
#if defined(XSDE_REUSE_STYLE_MIXIN)
# include "protocol-pimpl-mixin.hxx"
#elif defined(XSDE_REUSE_STYLE_TIEIN)
# include "protocol-pimpl-tiein.hxx"
#else
# error this example requires mixin or tiein parser reuse support
#endif
using std::cerr;
using std::endl;
using xml_schema::ro_string;
namespace protocol
{
// We are going to use our own "type ids" for the request
// types. You could instead use dynamic_cast if your system
// provides RTTI.
//
enum request_type
{
unknown_type,
balance_type,
withdraw_type
};
// Customize the xml_schema::document_pimpl object to handle our protocol
// vocabulary with multiple root elements.
//
class document_pimpl: public xml_schema::document_pimpl
{
public:
document_pimpl (balance_pskel& balance_p, withdraw_pskel& withdraw_p)
: result_type_ (unknown_type),
balance_p_ (balance_p),
withdraw_p_ (withdraw_p)
{
}
request_type
result_type () const
{
return result_type_;
}
request*
result ()
{
return result_.release ();
}
protected:
// This function is called to obtain the root element type parser.
// If the returned pointed is 0 then the whole document content
// is ignored. Note that the signature of this function varies
// depending on whether the runtime was built with polymorphism
// support.
//
virtual xml_schema::parser_base*
#ifndef XSDE_POLYMORPHIC
start_root_element (const ro_string& ns,
const ro_string& name)
#else
start_root_element (const ro_string& ns,
const ro_string& name,
const char* /* xsi:type */)
#endif
{
if (ns == "http://www.codesynthesis.com/protocol")
{
if (name == "balance")
{
balance_p_.pre ();
return &balance_p_;
}
else if (name == "withdraw")
{
balance_p_.pre ();
return &withdraw_p_;
}
cerr << "ignoring unknown request: " << name << endl;
return 0;
}
else
{
// This document is from the wrong namespace. If the runtime and
// the generated code are built with validation enabled then we
// can set an XML Schema error.
//
#ifdef XSDE_PARSER_VALIDATION
context_.schema_error (
xml_schema::parser_schema_error::unexpected_element);
#endif
return 0;
}
}
// 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)
{
// We could have handled the result directly in this function
// instead of storing it in the result_ variable.
//
if (parser == &balance_p_)
{
result_type_ = balance_type;
result_.reset (balance_p_.post_balance ());
}
else if (parser == &withdraw_p_)
{
result_type_ = withdraw_type;
result_.reset (withdraw_p_.post_withdraw ());
}
else
{
result_type_ = unknown_type;
result_.reset (0);
}
}
public:
// If we need to be able to reset and reuse the parser after
// an error then we also need to override reset() and reset
// the root parsers. We can also get smarter here by caching
// the parser that was used last and only reset that. Note
// that you always need to call _reset() from the base.
//
virtual void
reset ()
{
xml_schema::document_pimpl::reset ();
balance_p_._reset ();
withdraw_p_._reset ();
}
private:
request_type result_type_;
std::auto_ptr<request> result_;
balance_pskel& balance_p_;
withdraw_pskel& withdraw_p_;
};
}
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
{
using namespace protocol;
// Construct the parser.
//
xml_schema::unsigned_int_pimpl unsigned_int_p;
balance_pimpl balance_p;
withdraw_pimpl withdraw_p;
balance_p.parsers (unsigned_int_p); // account
withdraw_p.parsers (unsigned_int_p, // account
unsigned_int_p); // amount
// Parse the XML instance document.
//
document_pimpl doc_p (balance_p, withdraw_p);
// pre() and post() will be called as part of the start_root_element()
// and end_root_element() calls.
//
if (argc < 2)
doc_p.parse (std::cin);
else
doc_p.parse (argv[1]);
std::auto_ptr<request> r (doc_p.result ());
request_type t = doc_p.result_type ();
// Let's print what we've got.
//
switch (t)
{
case balance_type:
{
balance* b = static_cast<balance*> (r.get ());
cerr << "balance request for acc# " << b->account () << endl;
break;
}
case withdraw_type:
{
withdraw* w = static_cast<withdraw*> (r.get ());
cerr << "withdrawal request for acc# " << w->account () << ", "
<< "amount: " << w->amount () << endl;
break;
}
case unknown_type:
{
cerr << "unknown request" << endl;
break;
}
}
}
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 failure" << endl;
return 1;
}
return 0;
}
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