Complex classes like upload often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use upload, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 13 | class upload  | 
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| 14 | { | 
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| 15 | |||
| 16 | /**  | 
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| 17 | * Default directory persmissions (destination dir)  | 
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| 18 | */  | 
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| 19 | protected $default_permissions = 750;  | 
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| 20 | |||
| 21 | |||
| 22 | /**  | 
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| 23 | * File post array  | 
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| 24 | *  | 
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| 25 | * @var array  | 
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| 26 | */  | 
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| 27 | protected $files_post = array();  | 
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| 28 | |||
| 29 | |||
| 30 | /**  | 
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| 31 | * Destination directory  | 
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| 32 | *  | 
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| 33 | * @var string  | 
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| 34 | */  | 
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| 35 | protected $destination;  | 
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| 36 | |||
| 37 | |||
| 38 | /**  | 
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| 39 | * Fileinfo  | 
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| 40 | *  | 
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| 41 | * @var object  | 
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| 42 | */  | 
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| 43 | protected $finfo;  | 
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| 44 | |||
| 45 | |||
| 46 | /**  | 
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| 47 | * Data about file  | 
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| 48 | *  | 
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| 49 | * @var array  | 
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| 50 | */  | 
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| 51 | public $file = array();  | 
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| 52 | |||
| 53 | |||
| 54 | /**  | 
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| 55 | * Max. file size  | 
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| 56 | *  | 
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| 57 | * @var int  | 
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| 58 | */  | 
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| 59 | protected $max_file_size;  | 
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| 60 | |||
| 61 | |||
| 62 | /**  | 
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| 63 | * Allowed mime types  | 
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| 64 | *  | 
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| 65 | * @var array  | 
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| 66 | */  | 
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| 67 | protected $mimes = array();  | 
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| 68 | |||
| 69 | |||
| 70 | /**  | 
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| 71 | * External callback object  | 
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| 72 | *  | 
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| 73 | * @var obejct  | 
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| 74 | */  | 
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| 75 | protected $external_callback_object;  | 
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| 76 | |||
| 77 | |||
| 78 | /**  | 
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| 79 | * External callback methods  | 
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| 80 | *  | 
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| 81 | * @var array  | 
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| 82 | */  | 
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| 83 | protected $external_callback_methods = array();  | 
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| 84 | |||
| 85 | |||
| 86 | /**  | 
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| 87 | * Temp path  | 
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| 88 | *  | 
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| 89 | * @var string  | 
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| 90 | */  | 
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| 91 | protected $tmp_name;  | 
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| 92 | |||
| 93 | |||
| 94 | /**  | 
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| 95 | * Validation errors  | 
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| 96 | *  | 
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| 97 | * @var array  | 
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| 98 | */  | 
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| 99 | protected $validation_errors = array();  | 
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| 100 | |||
| 101 | |||
| 102 | /**  | 
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| 103 | * Filename (new)  | 
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| 104 | *  | 
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| 105 | * @var string  | 
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| 106 | */  | 
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| 107 | protected $filename;  | 
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| 108 | |||
| 109 | /**  | 
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| 110 | * File extension  | 
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| 111 | * @var string  | 
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| 112 | */  | 
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| 113 | protected $extension;  | 
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| 114 | |||
| 115 | /**  | 
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| 116 | * Internal callbacks (filesize check, mime, etc)  | 
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| 117 | *  | 
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| 118 | * @var array  | 
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| 119 | */  | 
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| 120 | private $callbacks = array();  | 
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| 121 | |||
| 122 | /**  | 
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| 123 | * Root dir  | 
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| 124 | *  | 
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| 125 | * @var string  | 
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| 126 | */  | 
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| 127 | protected $root;  | 
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| 128 | |||
| 129 | /**  | 
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| 130 | * Return upload object  | 
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| 131 | *  | 
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| 132 | * $destination = 'path/to/your/file/destination/folder';  | 
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| 133 | *  | 
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| 134 | * @param string $phpbb_root_path  | 
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| 135 | * @return Upload  | 
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| 136 | */  | 
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| 137 | public static function factory($phpbb_root_path)  | 
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| 141 | |||
| 142 | /**  | 
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| 143 | * Define ROOT constant and set & create destination path  | 
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| 144 | *  | 
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| 145 | * @param string $phpbb_root_path  | 
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| 146 | * @throws Exception  | 
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| 147 | */  | 
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| 148 | public function __construct($phpbb_root_path)  | 
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| 159 | |||
| 160 | /**  | 
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| 161 | * Set target filename  | 
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| 162 | *  | 
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| 163 | * @param string $filename  | 
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| 164 | */  | 
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| 165 | public function set_filename($filename)  | 
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| 169 | |||
| 170 | /**  | 
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| 171 | * Check & Save file  | 
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| 172 | *  | 
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| 173 | * Return data about current upload  | 
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| 174 | *  | 
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| 175 | * @return array  | 
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| 176 | */  | 
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| 177 | public function upload($filename = '')  | 
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| 185 | |||
| 186 | |||
| 187 | /**  | 
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| 188 | * Save file on server  | 
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| 189 | *  | 
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| 190 | * Return state data  | 
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| 191 | *  | 
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| 192 | * @return array  | 
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| 193 | */  | 
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| 194 | public function save()  | 
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| 199 | |||
| 200 | |||
| 201 | /**  | 
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| 202 | * Validate file (execute callbacks)  | 
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| 203 | *  | 
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| 204 | * Returns TRUE if validation successful  | 
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| 205 | *  | 
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| 206 | * @return bool  | 
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| 207 | */  | 
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| 208 | public function check()  | 
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| 221 | |||
| 222 | /**  | 
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| 223 | * Get current state data  | 
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| 224 | *  | 
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| 225 | * @return array  | 
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| 226 | */  | 
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| 227 | public function get_state()  | 
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| 231 | |||
| 232 | |||
| 233 | /**  | 
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| 234 | * Save file on server  | 
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| 235 | */  | 
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| 236 | protected function save_file()  | 
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| 260 | |||
| 261 | /**  | 
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| 262 | * Set data about file  | 
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| 263 | */  | 
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| 264 | protected function set_file_data()  | 
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| 279 | |||
| 280 | /**  | 
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| 281 | * Set validation error  | 
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| 282 | *  | 
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| 283 | * @param string $message  | 
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| 284 | */  | 
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| 285 | public function set_error($message)  | 
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| 289 | |||
| 290 | /**  | 
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| 291 | * Return validation errors  | 
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| 292 | *  | 
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| 293 | * @return array  | 
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| 294 | */  | 
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| 295 | public function get_errors()  | 
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| 299 | |||
| 300 | /**  | 
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| 301 | * Set external callback methods  | 
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| 302 | *  | 
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| 303 | * @param object $instance_of_callback_object  | 
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| 304 | * @param array $callback_methods  | 
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| 305 | * @throws Exception  | 
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| 306 | */  | 
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| 307 | public function callbacks($instance_of_callback_object, $callback_methods)  | 
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| 320 | |||
| 321 | /**  | 
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| 322 | * Execute callbacks  | 
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| 323 | */  | 
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| 324 | protected function validate()  | 
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| 340 | |||
| 341 | /**  | 
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| 342 | * Execute callbacks  | 
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| 343 | */  | 
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| 344 | protected function execute_callbacks($callbacks, $object)  | 
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| 350 | |||
| 351 | /**  | 
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| 352 | * File mime type validation callback  | 
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| 353 | *  | 
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| 354 | * @param mixed $object  | 
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| 355 | */  | 
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| 356 | protected function check_mime_type($object)  | 
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| 364 | |||
| 365 | /**  | 
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| 366 | * Set allowed mime types  | 
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| 367 | *  | 
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| 368 | * @param array $mimes  | 
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| 369 | */  | 
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| 370 | public function set_allowed_mime_types($mimes)  | 
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| 376 | |||
| 377 | /**  | 
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| 378 | * File size validation callback  | 
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| 379 | *  | 
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| 380 | * @param object $object  | 
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| 381 | */  | 
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| 382 | protected function check_file_size($object)  | 
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| 391 | |||
| 392 | /**  | 
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| 393 | * Set max. file size  | 
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| 394 | *  | 
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| 395 | * @param int $size  | 
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| 396 | */  | 
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| 397 | public function set_max_file_size($size)  | 
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| 403 | |||
| 404 | /**  | 
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| 405 | * Set File array to object  | 
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| 406 | *  | 
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| 407 | * @param array $file  | 
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| 408 | */  | 
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| 409 | public function file($file)  | 
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| 413 | |||
| 414 | /**  | 
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| 415 | * Set file array  | 
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| 416 | *  | 
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| 417 | * @param array $file  | 
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| 418 | */  | 
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| 419 | protected function set_file_array($file)  | 
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| 436 | |||
| 437 | /**  | 
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| 438 | * Checks whether Files post array is valid  | 
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| 439 | *  | 
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| 440 | * @return bool  | 
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| 441 | */  | 
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| 442 | protected function check_file_array($file)  | 
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| 450 | |||
| 451 | /**  | 
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| 452 | * Get file mime type  | 
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| 453 | *  | 
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| 454 | * @return string  | 
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| 455 | */  | 
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| 456 | protected function get_file_mime()  | 
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| 460 | |||
| 461 | /**  | 
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| 462 | * Get file size  | 
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| 463 | *  | 
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| 464 | * @return int  | 
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| 465 | */  | 
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| 466 | protected function get_file_size()  | 
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| 470 | |||
| 471 | /**  | 
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| 472 | * Set destination path (return TRUE on success)  | 
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| 473 | *  | 
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| 474 | * @param string $destination  | 
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| 475 | * @return bool  | 
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| 476 | */  | 
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| 477 | protected function set_destination($destination)  | 
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| 482 | |||
| 483 | /**  | 
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| 484 | * Checks whether destination folder exists  | 
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| 485 | *  | 
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| 486 | * @return bool  | 
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| 487 | */  | 
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| 488 | protected function destination_exist()  | 
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| 492 | |||
| 493 | /**  | 
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| 494 | * Create path to destination  | 
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| 495 | *  | 
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| 496 | * @return bool  | 
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| 497 | */  | 
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| 498 | protected function create_destination()  | 
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| 502 | |||
| 503 | /**  | 
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| 504 | * Set unique filename  | 
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| 505 | *  | 
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| 506 | * @return string  | 
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| 507 | */  | 
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| 508 | protected function create_new_filename()  | 
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| 513 | |||
| 514 | /**  | 
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| 515 | * Convert bytes to mb.  | 
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| 516 | *  | 
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| 517 | * @param int $bytes  | 
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| 518 | * @return int  | 
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| 519 | */  | 
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| 520 | protected function bytes_to_mb($bytes)  | 
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| 524 | |||
| 525 | |||
| 526 | } // end of Upload  | 
            
This check looks from parameters that have been defined for a function or method, but which are not used in the method body.