Utility to handle file uploads.

class.Uploader.php

<?php

namespace \net\zeddev\util;

/** An error while uploading. */
class UploaderException extends \Exception { }

/** An invalid type for uploaded file. */
class UploaderTypeException extends UploaderException { }

/** An oversize uploaded file. */
class UploaderSizeException extends UploaderException { }

/** 
 * Utility to handle file uploads.  Can be used like so:
 *
 *	$uploader = new Uploader();
 *	$uploader->upload('formNameOfFile', 'path/to/store');
 *
 * **NOTE:** This file is released as a stand-alone utility. The original
 * file and the associated unit test can be found on GitHub Gist -
 * [here](https://gist.github.com/zscott92/7655076).
 *
 * @author Zachary Scott <zscott.dev@gmail.com>
 */
class Uploader {
	
	public $imageMimes;
	public $pdfMimes;
	
	/** The name of the uploaded file. */
	public $name;
	
	/** The size of the uploaded file. */
	public $size;
	
	/** The mime type of the uploaded file. */
	public $type;
	
	/** The location of the uploaded file. */
	public $path;
	
	public function __construct() {
	
		// valid mime types for images
		$this->imageMimes = array(
			"image/gif",
			"image/jpeg",
			"image/jpg",
			"image/pjpeg",
			"image/x-png",
			"image/png"
		);
		
		// valid mime type for PDF files
		$this->pdfMimes = array(
			"application/pdf",
			"application/x-pdf"
		);
		
	}
	
	// returns english error message for file error code
	private function uploadError($code) {
		assert($code != null && is_int($code));		
		
		switch ($code) {
			
			case UPLOAD_ERR_INI_SIZE:
			case UPLOAD_ERR_FORM_SIZE:
				return "File is too large to upload!";
				
			case UPLOAD_ERR_PARTIAL:
				return "File upload was interrupted!";
				
			case UPLOAD_ERR_NO_FILE:
				return "No file was uploaded, please try again.";
			
			case UPLOAD_ERR_NO_TMP_DIR:
			case UPLOAD_ERR_CANT_WRITE:
			case UPLOAD_ERR_EXTENSION:
				return "File upload failed due to an internal error, please try again later.";				
				
			default: 
				return "Unknown file error!";
		}		
			
	}
	
	/** 
	 * Handles checking and moving an uploaded file. 
	 *
	 * @param $name The form name of the uploaded file.
	 * @param $dir The directory in which to place the file.
	 * @param $size The maximum size of the uploaded file.  `null` for no limit.
	 * @param $mimes The valid mime types to accept.  `null` for none.
	 */
	public function upload($name, $dir, $overwrite = false, $size = null, $mimes = null) {
		
		// check exists
		if (!isset($_FILES[$name]))
			throw new UploaderException("No file was uploaded, please try again");
		
		// check for upload error
		if ($_FILES[$name]["error"] > 0) {
			
			throw new UploaderException(
				$this->uploadError($_FILES[$name]["error"])
			);
			
		}
		
		// check the size of the file
		if ($size != null) {
			
			if ($_FILES[$name]['size'] > $size)
				throw new UploaderSizeException($_FILES[$name]['size']);			
			
		}
		
		// check mime type of uploaded file
		if ($mimes != null) {
			
			$type = $_FILES[$name]['type'];
			
			if (!in_array($type, $mimes))
				throw new UploaderTypeException($type);

		}
		
		$file = $_FILES[$name]['name'];
		$filePath = $dir.'/'.$_FILES[$name]['name'];		
		
		// check file does not already exist
		if (!$overwrite && file_exists($filePath))
			throw new UploaderException("File $file already exists.");
		
		// relocate
		move_uploaded_file(
			$_FILES[$name]['tmp_name'], 
			$filePath
		);
		
		// set file info
		$this->name = $_FILES[$name]['name'];
		$this->size = $_FILES[$name]['size'];
		$this->type = $_FILES[$name]['type'];
		$this->path = $filePath;
		
		
	}	
	
}

?>

upload.php

<?php

// NOTE requires class.ErrorList.php vvvv

require_once dirname(__FILE__).'/code/class.ErrorList.php';
require_once dirname(__FILE__).'/code/class.Uploader.php';

$err = new ErrorList();
$uploader = new Uploader();

// handle form
if (isset($_POST['form'])) {
	
	try {
		
		// handle file upload
		$uploader->upload(
			'file', 
			'upload', 
			isset($_POST['overwrite']), 
			204800,  // 200KB limit
			$uploader->imageMimes
		);

		// upload successful at this point	
		$msg = "File uploaded successfully.";

	} catch (UploaderTypeException $ex) {
		$err->err("File must be an image");
	} catch (UploaderSizeException $ex) {
		$err->err("File must be 100KB or less");
	} catch (UploaderException $ex) {
		$err->err($ex->getMessage());
	}
	
}

?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" 
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
	<title>Uploader Test</title>
	<style type="text/css">
	.error {
		color: red;
	}
	.msg {
		color: green;	
	}
	</style>
</head>
<body>
	<h1>Uploader Test</h1>
	<?php
	
	// report any errors
	echo $err->geterr();	
	
	// display message
	if (isset($msg))
		echo "<p class='msg'>$msg</p>";	

	// output uploaded file info
	if (isset($_POST['form'])) {
		echo "<p class='msg'>";
		echo "Name: ". $uploader->name ."<br />";
		echo "Size: ". sprintf('%.2f KiB', $uploader->size / 1024) ."<br />";
		echo "Type: ". $uploader->type ."<br />";
		echo "Path: ". $uploader->path ."<br />";
		echo "</p>\n";
	}
	
	?>
	<form action="upload.php" 
	      method="post" 
	      enctype="multipart/form-data">
	    
		<input type="file" name="file"/>
		<input type="checkbox" name="overwrite" value="1"/>Overwrite?<br />		
		
		<input type="submit" name="form" value="Upload"/>	
		
	</form>
	
</body>
</html>