As I promised before, below I developed an illustrative example that shows how to obtain useful information about a sample "defaultPath" directory, which also contains two text files called "file1.txt" and "file2.txt" respectively. For this specific example, I listed sequentially the different values outputted when a particular method is called, so you can see more clearly how the proxy class does its business.

Here is the example in question:

try{

	// instantiate 'ProxyDirectoryProcessor' object

	$pDirProc=new ProxyDirectoryProcessor();

	// display path of selected directory

	echo $pDirProc->getPath();

	/*

	displays the following:

	defaultPath

	*/
	
	// display size of directory entries

	echo $pDirProc->getSize();

	/* 

	displays the following: 

	Size for directory entries are as following:

	Size for current element is :0

	Size for current element is :0

	Size for current element is :29

	Size for current element is :29

	*/

	// display names of directory entries

	echo $pDirProc->getFileNames();

	/*

	displays the following:

	Name for directory entries are as following:

	Name of current file is : file1.txt

	Name of current file is : file2.txt

	*/

	// display timestamps of directory entries

	echo $pDirProc->getTimeStamps();

	/*

	displays the following:

	Timestamps for directory entries are as following:

	Timestamp of current file is : 1160523911

	Timestamp of current file is : 1160523922

	*/

	// display last access timestamps of directory entries

	echo $pDirProc->getLastTimeStamps();

	/*

	displays the following:

	Last access timestamps for directory entries are as following:

	Last access timestamp of current file is : 1160523911

	Last access timestamp of current file is : 1160523922

	*/
	
	// display inode timestamps of directory entries

        echo $pDirProc->getInodeLastTimeStamps();

        /*

	displays the following:

	Last inode modification timestamp for directory entries are 

as following:

	Last inode modification timestamp of current file is : 1160523911

	Last inode modification timestamp of current file is : 1160523922

	*/

}

catch(Exception $e){

	echo $e->getMessage();

	exit();

} 

After studying the above example, hopefully you'll have a better background on how the proxy pattern works. As homework, try defining more methods for the directory processor, and for the proxy class as well. Fun is already guaranteed!

Final thoughts

In this two-part series, I introduced the key points concerning the implementation of the proxy pattern in PHP 5. As you hopefully learned, this pattern can be used when you want to avoid an unnecessary instantiation of a particular object, something that eventually can improve the overall performance of your application.

As usual, see you in the next PHP tutorial!