Complex classes like MailChimp 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 MailChimp, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 13 | class MailChimp |
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| 14 | { |
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| 15 | private $api_key; |
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| 16 | private $api_endpoint = 'https://<dc>.api.mailchimp.com/3.0'; |
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| 17 | |||
| 18 | /* SSL Verification |
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| 19 | Read before disabling: |
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| 20 | http://snippets.webaware.com.au/howto/stop-turning-off-curlopt_ssl_verifypeer-and-fix-your-php-config/ |
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| 21 | */ |
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| 22 | public $verify_ssl = true; |
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| 23 | |||
| 24 | private $request_successful = false; |
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| 25 | private $last_error = ''; |
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| 26 | private $last_response = array(); |
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| 27 | private $last_request = array(); |
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| 28 | |||
| 29 | /** |
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| 30 | * Create a new instance |
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| 31 | * @param string $api_key Your MailChimp API key |
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| 32 | * @throws \Exception |
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| 33 | */ |
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| 34 | public function __construct($api_key) |
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| 47 | |||
| 48 | /** |
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| 49 | * Create a new instance of a Batch request. Optionally with the ID of an existing batch. |
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| 50 | * @param string $batch_id Optional ID of an existing batch, if you need to check its status for example. |
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| 51 | * @return Batch New Batch object. |
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| 52 | */ |
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| 53 | public function new_batch($batch_id = null) |
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| 57 | |||
| 58 | /** |
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| 59 | * Convert an email address into a 'subscriber hash' for identifying the subscriber in a method URL |
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| 60 | * @param string $email The subscriber's email address |
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| 61 | * @return string Hashed version of the input |
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| 62 | */ |
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| 63 | public function subscriberHash($email) |
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| 67 | |||
| 68 | /** |
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| 69 | * Was the last request successful? |
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| 70 | * @return bool True for success, false for failure |
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| 71 | */ |
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| 72 | public function success() |
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| 76 | |||
| 77 | /** |
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| 78 | * Get the last error returned by either the network transport, or by the API. |
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| 79 | * If something didn't work, this should contain the string describing the problem. |
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| 80 | * @return array|false describing the error |
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| 81 | */ |
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| 82 | public function getLastError() |
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| 86 | |||
| 87 | /** |
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| 88 | * Get an array containing the HTTP headers and the body of the API response. |
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| 89 | * @return array Assoc array with keys 'headers' and 'body' |
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| 90 | */ |
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| 91 | public function getLastResponse() |
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| 95 | |||
| 96 | /** |
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| 97 | * Get an array containing the HTTP headers and the body of the API request. |
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| 98 | * @return array Assoc array |
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| 99 | */ |
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| 100 | public function getLastRequest() |
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| 104 | |||
| 105 | /** |
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| 106 | * Make an HTTP DELETE request - for deleting data |
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| 107 | * @param string $method URL of the API request method |
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| 108 | * @param array $args Assoc array of arguments (if any) |
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| 109 | * @param int $timeout Timeout limit for request in seconds |
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| 110 | * @return array|false Assoc array of API response, decoded from JSON |
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| 111 | */ |
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| 112 | public function delete($method, $args = array(), $timeout = 10) |
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| 116 | |||
| 117 | /** |
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| 118 | * Make an HTTP GET request - for retrieving data |
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| 119 | * @param string $method URL of the API request method |
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| 120 | * @param array $args Assoc array of arguments (usually your data) |
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| 121 | * @param int $timeout Timeout limit for request in seconds |
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| 122 | * @return array|false Assoc array of API response, decoded from JSON |
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| 123 | */ |
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| 124 | public function get($method, $args = array(), $timeout = 10) |
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| 128 | |||
| 129 | /** |
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| 130 | * Make an HTTP PATCH request - for performing partial updates |
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| 131 | * @param string $method URL of the API request method |
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| 132 | * @param array $args Assoc array of arguments (usually your data) |
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| 133 | * @param int $timeout Timeout limit for request in seconds |
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| 134 | * @return array|false Assoc array of API response, decoded from JSON |
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| 135 | */ |
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| 136 | public function patch($method, $args = array(), $timeout = 10) |
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| 140 | |||
| 141 | /** |
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| 142 | * Make an HTTP POST request - for creating and updating items |
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| 143 | * @param string $method URL of the API request method |
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| 144 | * @param array $args Assoc array of arguments (usually your data) |
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| 145 | * @param int $timeout Timeout limit for request in seconds |
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| 146 | * @return array|false Assoc array of API response, decoded from JSON |
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| 147 | */ |
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| 148 | public function post($method, $args = array(), $timeout = 10) |
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| 152 | |||
| 153 | /** |
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| 154 | * Make an HTTP PUT request - for creating new items |
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| 155 | * @param string $method URL of the API request method |
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| 156 | * @param array $args Assoc array of arguments (usually your data) |
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| 157 | * @param int $timeout Timeout limit for request in seconds |
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| 158 | * @return array|false Assoc array of API response, decoded from JSON |
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| 159 | */ |
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| 160 | public function put($method, $args = array(), $timeout = 10) |
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| 164 | |||
| 165 | /** |
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| 166 | * Performs the underlying HTTP request. Not very exciting. |
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| 167 | * @param string $http_verb The HTTP verb to use: get, post, put, patch, delete |
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| 168 | * @param string $method The API method to be called |
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| 169 | * @param array $args Assoc array of parameters to be passed |
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| 170 | * @param int $timeout |
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| 171 | * @return array|false Assoc array of decoded result |
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| 172 | * @throws \Exception |
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| 173 | */ |
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| 174 | private function makeRequest($http_verb, $method, $args = array(), $timeout = 10) |
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| 266 | |||
| 267 | /** |
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| 268 | * @return string The url to the API endpoint |
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| 269 | */ |
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| 270 | public function getApiEndpoint() |
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| 274 | |||
| 275 | /** |
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| 276 | * Get the HTTP headers as an array of header-name => header-value pairs. |
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| 277 | * |
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| 278 | * The "Link" header is parsed into an associative array based on the |
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| 279 | * rel names it contains. The original value is available under |
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| 280 | * the "_raw" key. |
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| 281 | * |
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| 282 | * @param string $headersAsString |
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| 283 | * @return array |
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| 284 | */ |
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| 285 | private function getHeadersAsArray($headersAsString) |
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| 313 | |||
| 314 | /** |
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| 315 | * Extract all rel => URL pairs from the provided Link header value |
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| 316 | * |
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| 317 | * Mailchimp only implements the URI reference and relation type from |
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| 318 | * RFC 5988, so the value of the header is something like this: |
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| 319 | * |
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| 320 | * 'https://us13.api.mailchimp.com/schema/3.0/Lists/Instance.json; rel="describedBy", <https://us13.admin.mailchimp.com/lists/members/?id=XXXX>; rel="dashboard"' |
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| 321 | * |
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| 322 | * @param string $linkHeaderAsString |
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| 323 | * @return array |
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| 324 | */ |
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| 325 | private function getLinkHeaderAsArray($linkHeaderAsString) |
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| 337 | |||
| 338 | /** |
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| 339 | * Encode the data and attach it to the request |
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| 340 | * @param resource $ch cURL session handle, used by reference |
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| 341 | * @param array $data Assoc array of data to attach |
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| 342 | */ |
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| 343 | private function attachRequestPayload(&$ch, $data) |
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| 349 | |||
| 350 | /** |
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| 351 | * Decode the response and format any error messages for debugging |
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| 352 | * @param array $response The response from the curl request |
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| 353 | * @return array|false The JSON decoded into an array |
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| 354 | */ |
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| 355 | private function formatResponse($response) |
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| 365 | |||
| 366 | /** |
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| 367 | * Check if the response was successful or a failure. If it failed, store the error. |
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| 368 | * @param array $response The response from the curl request |
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| 369 | * @param array|false $formattedResponse The response body payload from the curl request |
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| 370 | * @return bool If the request was successful |
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| 371 | */ |
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| 372 | private function determineSuccess($response, $formattedResponse) |
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| 389 | |||
| 390 | /** |
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| 391 | * Find the HTTP status code from the headers or API response body |
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| 392 | * @param array $response The response from the curl request |
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| 393 | * @param array|false $formattedResponse The response body payload from the curl request |
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| 394 | * @return int HTTP status code |
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| 395 | */ |
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| 396 | private function findHTTPStatus($response, $formattedResponse) |
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| 408 | } |
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| 409 |