class.chip_download.php

<?php
/*
|-----------------
| Author:	Life.Object
| E-Mail:	life.object@gmail.com
| Website:	http://www.tutorialchip.com/
| Help:		http://www.tutorialchip.com/php-download-file-script/
| Version:	1.1
| Released: November 29, 2010
| Updated: December 23, 2010
|------------------
*/

class chip_download {
	
	/*
	|---------------------------
	| Properties
	|---------------------------
	*/
	
	private $download_hook = array();
	
	private $args = array(
						'download_path'			=>	NULL,
						'file'					=>	NULL,						
						'extension_check'		=>	TRUE,
						'referrer_check'		=>	FALSE,	
						'referrer'				=>	NULL,					
					);
	
	private $allowed_extensions = array(
						
						/* Archives */
						'zip'	=> 'application/zip',
						'7z'	=> 'application/octet-stream',
					
					  	/* Documents */
					  	'txt'	=> 'text/plain',
						'pdf'	=> 'application/pdf',
					  	'doc' 	=> 'application/msword',
					  	'xls'	=> 'application/vnd.ms-excel',
					  	'ppt'	=> 'application/vnd.ms-powerpoint',
					  
					  	/* Executables */
					  	'exe'	=> 'application/octet-stream',
					
					  	/* Images */
					  	'gif'	=> 'image/gif',
					  	'png'	=> 'image/png',
					  	'jpg'	=> 'image/jpeg',
					  	'jpeg'	=> 'image/jpeg',
					
					  	/* Audio */
					  	'mp3'	=> 'audio/mpeg',
					  	'wav'	=> 'audio/x-wav',
					
					  	/* Video */
					  	'mpeg'	=> 'video/mpeg',
					  	'mpg'	=> 'video/mpeg',
					  	'mpe'	=> 'video/mpeg',
					  	'mov'	=> 'video/quicktime',
					  	'avi'	=> 'video/x-msvideo'
					
					);
	

	/*
	|---------------------------
	| Constructor
	|
	| @public
	| @param array $args
	| @param array $allowed_extensions
	|
	|---------------------------
	*/
	
	public function __construct( $args = array(), $allowed_extensions = array()  ) {
		
		$this->set_args( $args );
		$this->set_allowed_extensions( $allowed_extensions );
						
	}
	
	/*
	|---------------------------
	| Print variable in readable format
	|
	| @public
	| @param string|array|object $var
	|
	|---------------------------
	*/
	
	public function chip_print( $var ) { 
		
		echo "<pre>";
    	print_r($var);
   	 	echo "</pre>";
	
	}
	
	/*
	|---------------------------
	| Update default arguments
	| It will update default array of class i.e $args
	|
	| @private
	| @param array $args - input arguments
	| @param array $defatuls - default arguments 
	| @return array
	|
	|---------------------------
	*/
	
	private function chip_parse_args( $args = array(), $defaults = array() ) { 
		return array_merge( $defaults, $args );	 
	}
	
	/*
	|---------------------------
	| Get extension and name of file
	|
	| @private
	| @param string $file_name 
	| @return array - having file_name and file_ext
	|
	|---------------------------
	*/
	
	private function chip_extension($file_name) {
		$temp = array();
		$temp['file_name'] = strtolower( substr( $file_name, 0, strripos( $file_name, '.' ) ) );
	    $temp['file_extension'] = strtolower( substr( $file_name, strripos( $file_name, '.' ) + 1 ) );
		return $temp;
	}
	
	/*
	|---------------------------
	| Set default arguments
	| It will set default array of class i.e $args
	|
	| @private
	| @param array $args
	| @return 0
	|
	|---------------------------
	*/
	
	private function set_args( $args = array() ) { 
		
		$defaults = $this->get_args();
		$args = $this->chip_parse_args( $args, $defaults );
		$this->args = $args;	 
	}
	
	/*
	|---------------------------
	| Get default arguments
	| It will get default array of class i.e $args
	|
	| @public
	| @return array
	|
	|---------------------------
	*/
	
	public function get_args() { 
		return $this->args;	 
	}
	
	/*
	|---------------------------
	| Set default allowed extensions
	| It will set default array of class i.e $allowed_extensions
	|
	| @private
	| @param array $allowed_extensions
	| @return 0
	|
	|---------------------------
	*/
	
	private function set_allowed_extensions( $allowed_extensions = array() ) { 
		
		$defaults = $this->get_allowed_extensions();
		$allowed_extensions = array_unique( $this->chip_parse_args( $allowed_extensions, $defaults ) );
		$this->allowed_extensions = $allowed_extensions;	 
	
	}
	
	/*
	|---------------------------
	| Get default allowed extensions
	| It will get default array of class i.e $allowed_extensions
	|
	| @public
	| @return array
	|
	|---------------------------
	*/
	
	public function get_allowed_extensions() { 
		return $this->allowed_extensions;	 
	}
	
	/*
	|---------------------------
	| Set Mimi Type
	| It will set default array of class i.e $allowed_extensions
	|
	| @private
	| @param string $file_path
	! @return string
	|
	|---------------------------
	*/
	
	private function set_mime_type( $file_path ) { 
		
		/* by Function - mime_content_type */
		if( function_exists( 'mime_content_type' ) ) {
			$file_mime_type = @mime_content_type( $file_path );
		}
		
		/* by Function - mime_content_type */
		else if( function_exists( 'finfo_file' ) ) {
			
			$finfo = @finfo_open(FILEINFO_MIME);
			$file_mime_type = @finfo_file($finfo, $file_path);
			finfo_close($finfo);  
		
		}
		
		/* Default - FALSE */
		else {
			$file_mime_type = FALSE;
		 }
		 
		 return $file_mime_type;	 
	
	}
	
	/*
	|---------------------------
	| Get Mimi Type
	| It will set default array of class i.e $allowed_extensions
	|
	| @public
	| @param string $file_path
	! @return string
	|
	|---------------------------
	*/
	
	public function get_mime_type( $file_path ) { 
		return $this->set_mime_type( $file_path );	 
	}
	
	/*
	|---------------------------
	| Pre Download Hook
	|
	| @private
	| @return 0
	|
	|---------------------------
	*/
	
	private function set_download_hook() { 
		
		/* Allowed Extensions */
		$allowed_extensions = $this->get_allowed_extensions();
		
		/* Arguments */
		$args = $this->get_args();		
		
		/* Extract Arguments */
		extract($args);
		
		/* Directory Depth */
		$dir_depth = dirname( $file );
		if ( !empty( $dir_depth ) && $dir_depth != "." ) {
			$download_path = $download_path . $dir_depth . "/";
		} 
		
		/* File Name */
		$file = basename( $file );
		
		/* File Path */
		$file_path = $download_path . $file;
		$this->download_hook['file_path'] = $file_path;
		
		/* File and File Path Validation */
		if( empty( $file ) || !file_exists( $file_path ) ) {
			$this->download_hook['download'] = FALSE;
			$this->download_hook['message'] = "Invalid File or File Path.";
			return 0;
		}
		
		/* File Name and Extension */
		$nameext = $this->chip_extension($file);
		$file_name = $nameext['file_name'];
		$file_extension = $nameext['file_extension'];
		
		$this->download_hook['file'] = $file;
		$this->download_hook['file_name'] = $file_name;
		$this->download_hook['file_extension'] = $file_extension;

		/* Allowed Extension - Validation */
		if ( $extension_check == TRUE && !array_key_exists( $file_extension, $allowed_extensions ) ) {
		  $this->download_hook['download'] = FALSE;
		  $this->download_hook['message'] = "File is not allowed to download"; 
		  return 0;
		}
		
		/* Referrer - Validation */		
		if ( $referrer_check == TRUE && !empty($referrer) && strpos( strtoupper( $_SERVER['HTTP_REFERER'] ), strtoupper( $referrer ) ) === FALSE ) {
			$this->download_hook['download'] = FALSE;
		 	$this->download_hook['message'] = "Internal server error - Please contact system administrator";
			return 0;
		}
		
		/* File Size in Bytes */
		$file_size = filesize($file_path);
		$this->download_hook['file_size'] = $file_size;
		
		/* File Mime Type - Auto, Manual, Default */
		$file_mime_type = $this->get_mime_type( $file_path );		
		if( empty( $file_mime_type ) ) {
			
			$file_mime_type = $allowed_extensions[$file_extension];
			if( empty( $file_mime_type ) ) {
				$file_mime_type = "application/force-download";
			}
		
		}		
		
		$this->download_hook['file_mime_type'] = $file_mime_type;
		
		$this->download_hook['download'] = TRUE;
		$this->download_hook['message'] = "File is ready to download";
		return 0;		
	
	}
	
	/*
	|---------------------------
	| Download Hook
	| Allows you to do some action before download
	|
	| @public
	| @return array
	|
	|---------------------------
	*/
	
	public function get_download_hook() { 
		$this->set_download_hook();
		return $this->download_hook;
	}
	
	/*
	|---------------------------
	| Post Download Hook
	|
	| @private
	| @return array
	|
	|---------------------------
	*/
	
	private function set_post_download_hook() { 
		return $this->download_hook;
	}
	
	/*
	|---------------------------
	| Download
	| Start download stream
	|
	| @public
	| @return 0
	|
	|---------------------------
	*/
	
	public function set_download() { 
		
		/* Download Hook */
		$download_hook = $this->set_post_download_hook();
		
		/* Extract */
		extract($download_hook);
		
		/* Recheck */
		if( $download_hook['download'] != TRUE ) {
			echo "File is not allowed to download";
			return 0;
		}
		
		/* Execution Time Unlimited */
		set_time_limit(0);
		
		/*
		|----------------
		| Header
		| Forcing a download using readfile()
		|----------------
		*/
		
		header('Content-Description: File Transfer');
		header('Content-Type: ' . $file_mime_type);
		header('Content-Disposition: attachment; filename=' . $file);
		header('Content-Transfer-Encoding: binary');
		header('Expires: 0');
		header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
		header('Pragma: public');
		header('Content-Length: ' . $file_size);
		ob_clean();
		flush();
		readfile($file_path);
		exit;
		
	}
	
	/*
	|---------------------------
	| Download
	| Start download stream
	|
	| @public
	| @return array
	|
	|---------------------------
	*/
	
	public function get_download() { 
		$this->set_download();
		exit;
	}

	/*
	|---------------------------
	| Destructor
	|---------------------------
	*/
	
	public function __destruct() {
	}
}
?>