Complex classes like WC_Download_Handler 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 WC_Download_Handler, and based on these observations, apply Extract Interface, too.
1 | <?php |
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18 | class WC_Download_Handler { |
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19 | |||
20 | /** |
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21 | * Hook in methods. |
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22 | */ |
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23 | public static function init() { |
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31 | |||
32 | /** |
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33 | * Check if we need to download a file and check validity. |
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34 | */ |
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35 | public static function download_product() { |
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56 | |||
57 | /** |
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58 | * Get a download from the database. |
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59 | * |
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60 | * @param array $args Contains email, order key, product id and download id |
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61 | * @return object |
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62 | * @access private |
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63 | */ |
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64 | private static function get_download_data( $args = array() ) { |
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80 | |||
81 | /** |
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82 | * Perform checks to see if the current user can download the file. |
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83 | * @param object $download_data |
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84 | * @access private |
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85 | */ |
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86 | private static function check_current_user_can_download( $download_data ) { |
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92 | |||
93 | /** |
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94 | * Check if an order is valid for downloading from. |
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95 | * @param array $download_data |
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96 | * @access private |
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97 | */ |
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98 | private static function check_order_is_valid( $download_data ) { |
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103 | |||
104 | /** |
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105 | * Check if there are downloads remaining. |
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106 | * @param array $download_data |
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107 | * @access private |
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108 | */ |
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109 | private static function check_downloads_remaining( $download_data ) { |
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114 | |||
115 | /** |
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116 | * Check if the download has expired. |
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117 | * @param array $download_data |
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118 | * @access private |
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119 | */ |
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120 | private static function check_download_expiry( $download_data ) { |
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125 | |||
126 | /** |
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127 | * Check if a download requires the user to login first. |
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128 | * @param array $download_data |
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129 | * @access private |
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130 | */ |
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131 | private static function check_download_login_required( $download_data ) { |
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145 | |||
146 | /** |
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147 | * Log the download + increase counts. |
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148 | * @param object $download_data |
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149 | */ |
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150 | public static function count_download( $download_data ) { |
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166 | |||
167 | /** |
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168 | * Download a file - hook into init function. |
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169 | * @param string $file_path URL to file |
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170 | * @param integer $product_id of the product being downloaded |
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171 | */ |
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172 | public static function download( $file_path, $product_id ) { |
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192 | |||
193 | /** |
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194 | * Redirect to a file to start the download. |
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195 | * @param string $file_path |
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196 | * @param string $filename |
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197 | */ |
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198 | public static function download_file_redirect( $file_path, $filename = '' ) { |
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202 | |||
203 | /** |
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204 | * Parse file path and see if its remote or local. |
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205 | * @param string $file_path |
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206 | * @return array |
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207 | */ |
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208 | public static function parse_file_path( $file_path ) { |
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242 | |||
243 | /** |
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244 | * Download a file using X-Sendfile, X-Lighttpd-Sendfile, or X-Accel-Redirect if available. |
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245 | * @param string $file_path |
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246 | * @param string $filename |
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247 | */ |
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248 | public static function download_file_xsendfile( $file_path, $filename ) { |
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269 | |||
270 | /** |
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271 | * Force download - this is the default method. |
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272 | * @param string $file_path |
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273 | * @param string $filename |
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274 | */ |
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275 | public static function download_file_force( $file_path, $filename ) { |
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290 | |||
291 | /** |
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292 | * Get content type of a download. |
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293 | * @param string $file_path |
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294 | * @return string |
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295 | * @access private |
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296 | */ |
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297 | private static function get_download_content_type( $file_path ) { |
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311 | |||
312 | /** |
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313 | * Set headers for the download. |
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314 | * @param string $file_path |
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315 | * @param string $filename |
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316 | * @access private |
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317 | */ |
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318 | private static function download_headers( $file_path, $filename ) { |
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333 | |||
334 | /** |
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335 | * Check and set certain server config variables to ensure downloads work as intended. |
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336 | */ |
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337 | private static function check_server_config() { |
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338 | wc_set_time_limit( 0 ); |
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339 | if ( function_exists( 'get_magic_quotes_runtime' ) && get_magic_quotes_runtime() && version_compare( phpversion(), '5.4', '<' ) ) { |
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340 | set_magic_quotes_runtime( 0 ); |
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341 | } |
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342 | if ( function_exists( 'apache_setenv' ) ) { |
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343 | @apache_setenv( 'no-gzip', 1 ); |
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344 | } |
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345 | @ini_set( 'zlib.output_compression', 'Off' ); |
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346 | @session_write_close(); |
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347 | } |
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348 | |||
349 | /** |
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350 | * Clean all output buffers. |
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351 | * |
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352 | * Can prevent errors, for example: transfer closed with 3 bytes remaining to read. |
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353 | * |
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354 | * @access private |
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355 | */ |
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356 | private static function clean_buffers() { |
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366 | |||
367 | /** |
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368 | * readfile_chunked. |
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369 | * |
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370 | * Reads file in chunks so big downloads are possible without changing PHP.INI - http://codeigniter.com/wiki/Download_helper_for_large_files/. |
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371 | * |
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372 | * @param string $file |
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373 | * @return bool Success or fail |
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374 | */ |
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375 | public static function readfile_chunked( $file ) { |
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394 | |||
395 | /** |
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396 | * Filter headers for IE to fix issues over SSL. |
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397 | * |
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398 | * IE bug prevents download via SSL when Cache Control and Pragma no-cache headers set. |
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399 | * |
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400 | * @param array $headers |
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401 | * @return array |
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402 | */ |
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403 | public static function ie_nocache_headers_fix( $headers ) { |
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410 | |||
411 | /** |
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412 | * Die with an error message if the download fails. |
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413 | * @param string $message |
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414 | * @param string $title |
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415 | * @param integer $status |
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416 | * @access private |
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417 | */ |
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418 | private static function download_error( $message, $title = '', $status = 404 ) { |
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424 | } |
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425 | |||
427 |
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: