ElementFactory Class Reference

A factory for creating elements based on their type. More...

#include <element_factory.hh>

List of all members.

Classes
class	UnknownElement
	Exception thrown if an Unknown element is being created. More...
Public Types
typedef Element *(*	Callback )(const char *)
typedef map< string, Callback >	Map
Public Member Functions
void	add (const string &key, Callback cb)
	Register a callback with the factory.
Element *	create (const string &key, const char *arg)
	Create an element.
Static Public Member Functions
static bool	can_create (const string &key)
	Checks whether a type exists.
Static Private Attributes
static Map	_map
	There is only one factory map.
static RegisterElements	_regelems
	A class which registers defined callbacks upon creation.

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Detailed Description

A factory for creating elements based on their type.

Elements are created via their string represented type. They are initialized via a c-style string. If this string is null, then a default value is assigned to the element.

Functions that perform the creation are registered with the factory at run-time.

An exception is throw on element creationg failure.

Similar to Dispatcher.

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Member Function Documentation

void ElementFactory::add	(	const string &	key,
		Callback	cb
	)

Register a callback with the factory.

Parameters:

key	the element id/type. Must be unique.
cb	function to be called when the element must be created.

bool ElementFactory::can_create

(

const string &

key

)

[static]

Checks whether a type exists.

Parameters:

key	the element to check for.

Returns:

true if the element can be create via the factory.

Element * ElementFactory::create	(	const string &	key,
		const char *	arg
	)

Create an element.

Returns:

the requested element. Caller is responsible for deletion.

Parameters:

key	the type of element that needs to be created.
arg	initial value of element. If null, a default is assigned.

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Member Data Documentation

ElementFactory::Map ElementFactory::_map [static, private]

There is only one factory map.

Creating additional factory objects is therefore safe. No need to pass a global factory around in the various classes.

RegisterElements ElementFactory::_regelems [static, private]

A class which registers defined callbacks upon creation.

Callbacks are thus registered once [static] and before the factory is actually used.

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The documentation for this class was generated from the following files:

• /home/greearb/git/xorp.ct.github/xorp/policy/common/element_factory.hh
• /home/greearb/git/xorp.ct.github/xorp/policy/common/element_factory.cc