Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like main_controller 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 main_controller, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 15 | class main_controller  | 
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| 16 | { | 
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| 17 | protected $auth;  | 
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| 18 | protected $config;  | 
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| 19 | protected $container;  | 
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| 20 | protected $extension_manager;  | 
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| 21 | protected $helper;  | 
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| 22 | protected $ppde_entity_currency;  | 
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| 23 | protected $ppde_entity_donation_pages;  | 
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| 24 | protected $ppde_entity_transactions;  | 
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| 25 | protected $ppde_operator_currency;  | 
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| 26 | protected $ppde_operator_donation_pages;  | 
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| 27 | protected $ppde_operator_transactions;  | 
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| 28 | protected $request;  | 
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| 29 | protected $template;  | 
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| 30 | protected $user;  | 
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| 31 | protected $root_path;  | 
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| 32 | protected $php_ext;  | 
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| 33 | /** @var array */  | 
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| 34 | protected $ext_meta = array();  | 
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| 35 | /** @var string */  | 
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| 36 | protected $ext_name;  | 
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| 37 | /** @var string */  | 
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| 38 | private $donation_body;  | 
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| 39 | /** @var array */  | 
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| 40 | private $donation_content_data;  | 
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| 41 | /** @var string */  | 
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| 42 | private $return_args_url;  | 
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| 43 | /** @var string */  | 
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| 44 | private $u_action;  | 
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| 45 | |||
| 46 | /**  | 
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| 47 | * Constructor  | 
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| 48 | *  | 
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| 49 | * @param \phpbb\auth\auth $auth Auth object  | 
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| 50 | * @param \phpbb\config\config $config Config object  | 
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| 51 | * @param ContainerInterface $container Service container interface  | 
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| 52 | * @param \phpbb\extension\manager $extension_manager An instance of the phpBB extension  | 
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| 53 | * manager  | 
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| 54 | * @param \phpbb\controller\helper $helper Controller helper object  | 
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| 55 | * @param \skouat\ppde\entity\currency $ppde_entity_currency Currency entity object  | 
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| 56 | * @param \skouat\ppde\entity\donation_pages $ppde_entity_donation_pages Donation pages entity object  | 
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| 57 | * @param \skouat\ppde\entity\transactions $ppde_entity_transactions Transactions log entity object  | 
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| 58 | * @param \skouat\ppde\operators\currency $ppde_operator_currency Currency operator object  | 
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| 59 | * @param \skouat\ppde\operators\donation_pages $ppde_operator_donation_pages Donation pages operator object  | 
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| 60 | * @param \skouat\ppde\operators\transactions $ppde_operator_transactions Transactions log operator object  | 
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| 61 | * @param \phpbb\request\request $request Request object  | 
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| 62 | * @param \phpbb\template\template $template Template object  | 
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| 63 | * @param \phpbb\user $user User object  | 
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| 64 | * @param string $root_path phpBB root path  | 
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| 65 | * @param string $php_ext phpEx  | 
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| 66 | *  | 
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| 67 | * @return \skouat\ppde\controller\main_controller  | 
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| 68 | * @access public  | 
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| 69 | */  | 
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| 70 | public function __construct(\phpbb\auth\auth $auth, \phpbb\config\config $config, ContainerInterface $container, \phpbb\extension\manager $extension_manager, \phpbb\controller\helper $helper, \skouat\ppde\entity\currency $ppde_entity_currency, \skouat\ppde\entity\donation_pages $ppde_entity_donation_pages, \skouat\ppde\entity\transactions $ppde_entity_transactions, \skouat\ppde\operators\currency $ppde_operator_currency, \skouat\ppde\operators\donation_pages $ppde_operator_donation_pages, \skouat\ppde\operators\transactions $ppde_operator_transactions, \phpbb\request\request $request, \phpbb\template\template $template, \phpbb\user $user, $root_path, $php_ext)  | 
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| 89 | |||
| 90 | public function handle()  | 
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| 136 | |||
| 137 | public function donorlist_handle()  | 
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| 223 | |||
| 224 | /**  | 
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| 225 | * @return bool  | 
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| 226 | * @access public  | 
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| 227 | */  | 
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| 228 | public function can_use_ppde()  | 
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| 232 | |||
| 233 | /**  | 
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| 234 | * @return bool  | 
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| 235 | * @access public  | 
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| 236 | */  | 
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| 237 | public function can_view_ppde_donorlist()  | 
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| 241 | |||
| 242 | /**  | 
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| 243 | * @param string $set_return_args_url  | 
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| 244 | *  | 
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| 245 | * @return null  | 
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| 246 | * @access private  | 
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| 247 | */  | 
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| 248 | private function set_return_args_url($set_return_args_url)  | 
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| 270 | |||
| 271 | /**  | 
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| 272 | * Get content of current donation pages  | 
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| 273 | *  | 
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| 274 | * @param string $return_args_url  | 
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| 275 | *  | 
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| 276 | * @return array  | 
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| 277 | * @access private  | 
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| 278 | */  | 
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| 279 | private function get_donation_content_data($return_args_url)  | 
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| 285 | |||
| 286 | /**  | 
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| 287 | * Build pull down menu options of available currency  | 
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| 288 | *  | 
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| 289 | * @param int $config_value Currency identifier; default: 0  | 
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| 290 | *  | 
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| 291 | * @return null  | 
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| 292 | * @access public  | 
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| 293 | */  | 
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| 294 | public function build_currency_select_menu($config_value = 0)  | 
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| 314 | |||
| 315 | /**  | 
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| 316 | * Build pull down menu options of available currency value  | 
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| 317 | *  | 
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| 318 | * @return string List of currency value set in ACP for dropdown menu  | 
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| 319 | * @access private  | 
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| 320 | */  | 
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| 321 | private function build_currency_value_select_menu()  | 
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| 339 | |||
| 340 | /**  | 
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| 341 | * Get dropbox config value  | 
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| 342 | *  | 
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| 343 | * @return bool  | 
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| 344 | * @access private  | 
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| 345 | */  | 
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| 346 | private function get_dropbox_status()  | 
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| 350 | |||
| 351 | /**  | 
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| 352 | * Force dropbox value to integer  | 
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| 353 | *  | 
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| 354 | * @param int $value  | 
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| 355 | *  | 
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| 356 | * @return int  | 
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| 357 | */  | 
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| 358 | private function settype_dropbox_int_value($value = 0)  | 
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| 367 | |||
| 368 | /**  | 
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| 369 | * Build PayPal hidden fields  | 
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| 370 | *  | 
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| 371 | * @return string PayPal hidden field needed to fill PayPal forms  | 
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| 372 | * @access private  | 
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| 373 | */  | 
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| 374 | private function paypal_hidden_fields()  | 
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| 390 | |||
| 391 | /**  | 
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| 392 | * Get PayPal account id  | 
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| 393 | *  | 
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| 394 | * @return string $this Paypal account Identifier  | 
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| 395 | * @access private  | 
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| 396 | */  | 
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| 397 | private function get_account_id()  | 
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| 401 | |||
| 402 | /**  | 
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| 403 | * Check if Sandbox is enabled  | 
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| 404 | *  | 
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| 405 | * @return bool  | 
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| 406 | * @access public  | 
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| 407 | */  | 
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| 408 | public function use_sandbox()  | 
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| 412 | |||
| 413 | /**  | 
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| 414 | * Check if IPN is enabled  | 
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| 415 | *  | 
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| 416 | * @return bool  | 
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| 417 | * @access public  | 
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| 418 | */  | 
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| 419 | public function use_ipn()  | 
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| 423 | |||
| 424 | /**  | 
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| 425 | * Generate PayPal return URL  | 
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| 426 | *  | 
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| 427 | * @param string $arg  | 
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| 428 | *  | 
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| 429 | * @return string  | 
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| 430 | * @access private  | 
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| 431 | */  | 
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| 432 | private function generate_paypal_return_url($arg)  | 
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| 436 | |||
| 437 | /**  | 
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| 438 | * Generate PayPal return notify URL  | 
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| 439 | *  | 
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| 440 | * @return string  | 
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| 441 | * @access private  | 
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| 442 | */  | 
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| 443 | private function generate_paypal_notify_return_url()  | 
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| 447 | |||
| 448 | /**  | 
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| 449 | * Get PayPal URL  | 
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| 450 | * Used in form and in IPN process  | 
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| 451 | *  | 
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| 452 | * @param bool $is_test_ipn  | 
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| 453 | *  | 
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| 454 | * @return string  | 
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| 455 | * @access public  | 
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| 456 | */  | 
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| 457 | public function get_paypal_url($is_test_ipn = false)  | 
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| 461 | |||
| 462 | /**  | 
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| 463 | * Assign statistics vars to the template  | 
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| 464 | *  | 
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| 465 | * @return null  | 
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| 466 | * @access public  | 
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| 467 | */  | 
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| 468 | public function display_stats()  | 
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| 489 | |||
| 490 | /**  | 
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| 491 | * Get default currency symbol  | 
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| 492 | *  | 
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| 493 | * @param int $id  | 
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| 494 | *  | 
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| 495 | * @return array  | 
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| 496 | * @access public  | 
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| 497 | */  | 
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| 498 | public function get_default_currency_data($id = 0)  | 
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| 502 | |||
| 503 | /**  | 
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| 504 | * Retrieve the language key for donation goal  | 
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| 505 | *  | 
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| 506 | * @param string $currency_symbol Currency symbol  | 
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| 507 | * @param bool $on_left Symbol position  | 
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| 508 | *  | 
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| 509 | * @return string  | 
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| 510 | * @access public  | 
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| 511 | */  | 
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| 512 | public function get_ppde_goal_langkey($currency_symbol, $on_left = true)  | 
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| 529 | |||
| 530 | /**  | 
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| 531 | * Put the currency on the left or on the right of the amount  | 
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| 532 | *  | 
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| 533 | * @param int $value  | 
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| 534 | * @param string $currency  | 
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| 535 | * @param bool $on_left  | 
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| 536 | *  | 
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| 537 | * @return string  | 
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| 538 | */  | 
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| 539 | private function get_amount($value, $currency, $on_left = true)  | 
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| 543 | |||
| 544 | /**  | 
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| 545 | * Retrieve the language key for donation raised  | 
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| 546 | *  | 
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| 547 | * @param string $currency_symbol Currency symbol  | 
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| 548 | * @param bool $on_left Symbol position  | 
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| 549 | *  | 
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| 550 | * @return string  | 
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| 551 | * @access public  | 
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| 552 | */  | 
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| 553 | public function get_ppde_raised_langkey($currency_symbol, $on_left = true)  | 
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| 566 | |||
| 567 | /**  | 
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| 568 | * Retrieve the language key for donation used  | 
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| 569 | *  | 
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| 570 | * @param string $currency_symbol Currency symbol  | 
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| 571 | * @param bool $on_left Symbol position  | 
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| 572 | *  | 
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| 573 | * @return string  | 
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| 574 | * @access public  | 
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| 575 | */  | 
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| 576 | public function get_ppde_used_langkey($currency_symbol, $on_left = true)  | 
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| 593 | |||
| 594 | /**  | 
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| 595 | * Generate statistics percent for display  | 
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| 596 | *  | 
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| 597 | * @return null  | 
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| 598 | * @access private  | 
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| 599 | */  | 
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| 600 | private function generate_stats_percent()  | 
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| 612 | |||
| 613 | /**  | 
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| 614 | * Assign statistics percent vars to template  | 
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| 615 | *  | 
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| 616 | * @param integer $multiplicand  | 
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| 617 | * @param integer $dividend  | 
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| 618 | * @param string $type  | 
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| 619 | *  | 
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| 620 | * @return null  | 
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| 621 | * @access public  | 
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| 622 | */  | 
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| 623 | private function assign_vars_stats_percent($multiplicand, $dividend, $type = '')  | 
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| 630 | |||
| 631 | /**  | 
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| 632 | * Send data to the template file  | 
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| 633 | *  | 
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| 634 | * @return \Symfony\Component\HttpFoundation\Response  | 
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| 635 | * @access private  | 
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| 636 | */  | 
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| 637 | private function send_data_to_template()  | 
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| 650 | |||
| 651 | /**  | 
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| 652 | * Check if cURL is available  | 
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| 653 | *  | 
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| 654 | * @return bool  | 
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| 655 | * @access public  | 
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| 656 | */  | 
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| 657 | public function check_curl()  | 
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| 677 | |||
| 678 | /**  | 
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| 679 | * Get extension metadata  | 
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| 680 | *  | 
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| 681 | * @return null  | 
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| 682 | * @access protected  | 
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| 683 | */  | 
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| 684 | protected function get_ext_meta()  | 
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| 691 | |||
| 692 | /**  | 
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| 693 | * Load metadata for this extension  | 
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| 694 | *  | 
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| 695 | * @return array  | 
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| 696 | * @access public  | 
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| 697 | */  | 
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| 698 | public function load_metadata()  | 
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| 720 | |||
| 721 | /**  | 
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| 722 | * Retrieve the extension name  | 
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| 723 | *  | 
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| 724 | * @return null  | 
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| 725 | * @access protected  | 
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| 726 | */  | 
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| 727 | protected function retrieve_ext_name()  | 
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| 732 | |||
| 733 | /**  | 
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| 734 | * Check if fsockopen is available  | 
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| 735 | *  | 
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| 736 | * @return bool  | 
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| 737 | * @access public  | 
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| 738 | */  | 
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| 739 | public function check_fsockopen()  | 
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| 754 | }  | 
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| 755 | 
It is generally a best practice as it is often more readable to use concatenation instead of interpolation for variables inside strings.