Plugin publishing - dynamic linking and loading

plugin1.cpp

// now in your plugin.cpp
#include <Resources.h>

#define PLUGIN_API __declspec(dllexport)

PLUGIN_PARAMS(
  L"param1",
  L"param2",
  L"param3",
  L"param4",
  )

#include <ResourceEx.h>

PLUGIN_NAMED_PARAMS(
	L"name", L"value", // or embraced :)
	{L"name2", L"value2"}
	);

Resources.h

// to publish supported plugin strings
// use a single dllexport
// then just LoadLibrary and GetProcAddress in your framework

// defined in the framework.h
#define PLUGIN_PARAMS(...) PLUGIN_API const wchar_t* const * plugin_params(size_t& count) \
{ \
  static const wchar_t* const params[] = \
  { __VA_ARGS__}; \
  count = sizeof(params)/sizeof(wchar_t*); \
  return params; \
}

// SIMPLIFIED VERSION - no count, just trailing NULL (unsafe)
// signature: PLUGIN_API const wchar_t* const * plugin_params()
// static const wchar_t* const params[] = {__VA_ARGS__, 0}
// or
// static const wchar_t* const params[] = {__VA_ARGS__ L"", 0}
// - trick to prevent empty PLUGIN_PARAMS() or missing trailing comma errors

ResourcesEx.h

// EXTENDED VERSION with structures

struct ParamDefinition // defines a single published parameter
{
  const wchar_t *name, *value;
};

// Enumerated version
// in this case provide ParamEnum in your framework, 
// so plugin authors can implement predefined stuff
enum ParamEnum : size_t {default_param, optional_param};

struct ParamDefinition2
{
  ParamEnum param_id;
  const wchar_t* value;
};

// of course there can also be a flag field in ParamDefinition
// describing additional information

#define PLUGIN_NAMED_PARAMS(...) PLUGINL_API const ParamDefinition* const plugin_named_params(size_t& count) \
{ \
	static const ParamDefinition params[] = {__VA_ARGS__}; \
	count = sizeof(params)/sizeof(ParamDefinition); \
	return params; \
}


// NOTE:
// you can use this mechanism to publish functions
typedef void (plugin_func_t*)(void);

struct FunctionDefinition
{
  const wchar_t* name;
  plugin_func_t ptr;
}