navigation_cache Class Reference

The cache class used by global navigation and settings navigation. More...

Public Member Functions
	__construct ($area, $timeout=1800)
	Contructor for the cache.
	__get ($key)
	Magic Method to retrieve something by simply calling using = cache->key.
	__set ($key, $information)
	Magic method that simply uses set(); to store something in the cache.
	cached ($key)
	Check the existence of the identifier in the cache.
	clear ()
	Wipes the entire cache, good to force regeneration.
	compare ($key, $value, $serialise=true)
	Compare something to it's equivilant in the cache.
	set ($key, $information)
	Sets some information against the cache (session) for later retrieval.
	volatile ($setting=true)
	Marks the cache as being volatile (likely to change)

Static Public Member Functions
static	destroy_volatile_caches ()
	Destroys all caches marked as volatile.

Public Attributes
int const	CACHETIME = 0
	cache time information
int const	CACHEUSERID = 1
	cache user id
int const	CACHEVALUE = 2
	cache value

Static Public Attributes
static null array	$volatilecaches
	An array of navigation cache areas to expire on shutdown.

Protected Member Functions
	ensure_session_cache_initialised ()
	Used to set up the cache within the SESSION.
	garbage_collection ()
	Checks all cache entries and removes any that have expired, good ole cleanup.

Protected Attributes
string	$area
	The string to use to segregate this particular cache.
int	$creation
	represents the time created
stdClass	$currentcontext
	The current context.
array	$session
	An array of session keys.
int	$timeout
	a time that the information will time out

Detailed Description

The cache class used by global navigation and settings navigation.

It is basically an easy access point to session with a bit of smarts to make sure that the information that is cached is valid still.

Example use: if (!$cache->viewdiscussion()) { // Code to do stuff and produce cachable content $cache->viewdiscussion = has_capability('mod/forum:viewdiscussion', $coursecontext); } $content = $cache->viewdiscussion;

Copyright

2009 Sam Hemelryk

License

http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

Constructor & Destructor Documentation

__construct()

navigation_cache::__construct	(		$area,
			$timeout = 1800 )

Contructor for the cache.

Requires two arguments

Parameters

string	$area	The string to use to segregate this particular cache it can either be unique to start a fresh cache or if you want to share a cache then make it the string used in the original cache
int	$timeout	The number of seconds to time the information out after

Member Function Documentation

__get()

navigation_cache::__get

(

$key

)

Magic Method to retrieve something by simply calling using = cache->key.

Parameters

mixed

$key

The identifier for the information you want out again

Return values

void|mixed

Either void or what ever was put in

__set()

navigation_cache::__set	(		$key,
			$information )

Magic method that simply uses set(); to store something in the cache.

Parameters

string | int	$key
mixed	$information

cached()

navigation_cache::cached

(

$key

)

Check the existence of the identifier in the cache.

Parameters

string | int

$key

Return values

bool

compare()

navigation_cache::compare	(		$key,
			$value,
			$serialise = true )

Compare something to it's equivilant in the cache.

Parameters

string	$key
mixed	$value
bool	$serialise	Whether to serialise the value before comparison this should only be set to false if the value is already serialised

Return values

bool	If the value is the same false if it is not set or doesn't match

destroy_volatile_caches()

static navigation_cache::destroy_volatile_caches ( )

static

Destroys all caches marked as volatile.

This function is static and works in conjunction with the static volatilecaches property of navigation cache. Because this function is static it manually resets the cached areas back to an empty array.

ensure_session_cache_initialised()

navigation_cache::ensure_session_cache_initialised ( )

protected

Used to set up the cache within the SESSION.

This is called for each access and ensure that we don't put anything into the session before it is required.

set()

navigation_cache::set	(		$key,
			$information )

Sets some information against the cache (session) for later retrieval.

Parameters

string | int	$key
mixed	$information

volatile()

navigation_cache::volatile

(

$setting = true

)

Marks the cache as being volatile (likely to change)

Any caches marked as volatile will be destroyed at the on shutdown by navigation_node::destroy_volatile_caches() which is registered as a shutdown function if any caches are marked as volatile.

Parameters

bool

$setting

True to destroy the cache false not too

Member Data Documentation

$area

string navigation_cache::$area

protected

The string to use to segregate this particular cache.

It can either be unique to start a fresh cache or if you want to share a cache then make it the string used in the original cache.

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

• lib/navigationlib.php