Initialization

Table of Contents

• About
• Usage
• Further Reading

About

The macro MAXON_INITIALIZATION() is used to execute code when the application starts and when it shuts down. This is typically useful to allocate and free global data.

Warning

If the "init" functions of MAXON_INITIALIZATION() returns an error, all components defined in the current source file will not be loaded.

Usage

One can simply call global functions in the MAXON_INITIALIZATION() macro.

Warning

MAXON_INITIALIZATION() is called before the classic core is loaded. This means that classic API functions and classes (e.g. GePrint()) cannot be used in this context.

// This example declares a global string containing the machine name.
// MAXON_INITIALIZATION is used to set the value on start up and free the resource on shut down.
 
#include "maxon/module.h"
 
#include "maxon/string.h"
#include "maxon/application.h"
#include "maxon/machineinfo.h"
 
maxon::String* g_machineName = nullptr; // global string containing the machine name
 
// called on system start
static maxon::Result<void> InitGlobalString()
{
  iferr_scope;
 
  // allocate global string
  g_machineName = NewObj(maxon::String) iferr_return;
 
  // get machine data
  const maxon::DataDictionary data = maxon::Application::GetMachineInfo();
  // get machine name
  *g_machineName = data.Get(maxon::MACHINEINFO::COMPUTERNAME) iferr_return;
 
  return maxon::OK;
}
 
// called on system end
static void ClearGlobalString()
{
  // delete global string
  if (g_machineName != nullptr)
    DeleteObj(g_machineName);
}
 
MAXON_INITIALIZATION(InitGlobalString, ClearGlobalString);

Or simply use a lambda within the macro itself:

// This example declares a global string containing the user name.
// MAXON_INITIALIZATION is used to set the value on start up and free the resource on shut down.
 
maxon::String* g_userName = nullptr;  // global string containing the user name
 
MAXON_INITIALIZATION(
 
  // system startup
  []() -> maxon::Result<void>
  {
    iferr_scope;
 
// allocate global string
    g_userName = NewObj(maxon::String) iferr_return;
 
    // get machine data
    const maxon::DataDictionary data = maxon::Application::GetMachineInfo();
// get machine name
    *g_userName = data.Get(maxon::MACHINEINFO::USERNAME) iferr_return;
 
    return maxon::OK;
  },
// system shutdown
  []()
  {
    // delete global string
    DeleteObj(g_userName);
  });

If no function should be called nullptr can be set.

Further Reading

• Entity Creation