/**
* Wrap a Closure such that it is shared.
*
* @param \Closure $closure
* @return \Closure
*/
public function share(Closure $closure)// because this so we need php version is 5.4+
{// Wrap a closure such that is shared
return function ($container) use ($closure) {
// We'll simply declare a static variable within the Closures and if it has
// not been set we will execute the given Closures to resolve this value
// and return it back to these consumers of the method as an instance.
static $object;// check has, or closure it.
if (is_null($object)) {
$object = $closure($container);// use a closure class to bind to the container
}
return $object;
};// a Closure class is a special class
}
/**
* "Extend" an abstract type in the container.
*
* @param string $abstract
* @param \Closure $closure
* @return void
*
* @throws \InvalidArgumentException
*/
public function extend($abstract, Closure $closure)// a extend type ,parameter is a abstract class,and other is closure.
{
$abstract = $this->normalize($abstract);// get a normal string that we need
if (isset($this->instances[$abstract])) {// check it is set in the instance array,
$this->instances[$abstract] = $closure($this->instances[$abstract], $this);
// if isset ,use the closure function to action about it.
$this->rebound($abstract);// get the rebound function
} else {
$this->extenders[$abstract][] = $closure;// set the extender
}
}
