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 | const TIMEOUT = 10; |
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19 | |||
20 | /* SSL Verification |
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21 | Read before disabling: |
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22 | http://snippets.webaware.com.au/howto/stop-turning-off-curlopt_ssl_verifypeer-and-fix-your-php-config/ |
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23 | */ |
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24 | public $verify_ssl = true; |
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25 | |||
26 | private $request_successful = false; |
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27 | private $last_error = ''; |
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28 | private $last_response = array(); |
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29 | private $last_request = array(); |
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30 | |||
31 | /** |
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32 | * Create a new instance |
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33 | * @param string $api_key Your MailChimp API key |
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34 | * @param string $api_endpoint Optional custom API endpoint |
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35 | * @throws \Exception |
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36 | */ |
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37 | public function __construct($api_key, $api_endpoint = null) |
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38 | { |
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39 | $this->api_key = $api_key; |
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40 | |||
41 | if ($api_endpoint === null) { |
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42 | if (strpos($this->api_key, '-') === false) { |
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43 | throw new \Exception("Invalid MailChimp API key `{$api_key}` supplied."); |
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44 | } |
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45 | list(, $data_center) = explode('-', $this->api_key); |
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46 | $this->api_endpoint = str_replace('<dc>', $data_center, $this->api_endpoint); |
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47 | } else { |
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48 | $this->api_endpoint = $api_endpoint; |
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49 | } |
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50 | |||
51 | $this->last_response = array('headers' => null, 'body' => null); |
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52 | } |
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53 | |||
54 | /** |
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55 | * Create a new instance of a Batch request. Optionally with the ID of an existing batch. |
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56 | * @param string $batch_id Optional ID of an existing batch, if you need to check its status for example. |
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57 | * @return Batch New Batch object. |
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58 | */ |
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59 | public function new_batch($batch_id = null) |
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60 | { |
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61 | return new Batch($this, $batch_id); |
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62 | } |
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63 | |||
64 | /** |
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65 | * @return string The url to the API endpoint |
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66 | */ |
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67 | public function getApiEndpoint() |
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68 | { |
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69 | return $this->api_endpoint; |
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70 | } |
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71 | |||
72 | |||
73 | /** |
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74 | * Convert an email address into a 'subscriber hash' for identifying the subscriber in a method URL |
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75 | * @param string $email The subscriber's email address |
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76 | * @return string Hashed version of the input |
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77 | */ |
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78 | public function subscriberHash($email) |
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79 | { |
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80 | return md5(strtolower($email)); |
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81 | } |
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82 | |||
83 | /** |
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84 | * Was the last request successful? |
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85 | * @return bool True for success, false for failure |
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86 | */ |
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87 | public function success() |
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88 | { |
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89 | return $this->request_successful; |
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90 | } |
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91 | |||
92 | /** |
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93 | * Get the last error returned by either the network transport, or by the API. |
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94 | * If something didn't work, this should contain the string describing the problem. |
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95 | * @return array|false describing the error |
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96 | */ |
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97 | public function getLastError() |
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98 | { |
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99 | return $this->last_error ?: false; |
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100 | } |
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101 | |||
102 | /** |
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103 | * Get an array containing the HTTP headers and the body of the API response. |
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104 | * @return array Assoc array with keys 'headers' and 'body' |
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105 | */ |
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106 | public function getLastResponse() |
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107 | { |
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108 | return $this->last_response; |
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109 | } |
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110 | |||
111 | /** |
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112 | * Get an array containing the HTTP headers and the body of the API request. |
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113 | * @return array Assoc array |
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114 | */ |
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115 | public function getLastRequest() |
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116 | { |
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117 | return $this->last_request; |
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118 | } |
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119 | |||
120 | /** |
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121 | * Make an HTTP DELETE request - for deleting data |
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122 | * @param string $method URL of the API request method |
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123 | * @param array $args Assoc array of arguments (if any) |
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124 | * @param int $timeout Timeout limit for request in seconds |
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125 | * @return array|false Assoc array of API response, decoded from JSON |
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126 | */ |
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127 | public function delete($method, $args = array(), $timeout = self::TIMEOUT) |
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128 | { |
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129 | return $this->makeRequest('delete', $method, $args, $timeout); |
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130 | } |
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131 | |||
132 | /** |
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133 | * Make an HTTP GET request - for retrieving data |
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134 | * @param string $method URL of the API request method |
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135 | * @param array $args Assoc array of arguments (usually your data) |
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136 | * @param int $timeout Timeout limit for request in seconds |
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137 | * @return array|false Assoc array of API response, decoded from JSON |
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138 | */ |
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139 | public function get($method, $args = array(), $timeout = self::TIMEOUT) |
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140 | { |
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141 | return $this->makeRequest('get', $method, $args, $timeout); |
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142 | } |
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143 | |||
144 | /** |
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145 | * Make an HTTP PATCH request - for performing partial updates |
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146 | * @param string $method URL of the API request method |
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147 | * @param array $args Assoc array of arguments (usually your data) |
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148 | * @param int $timeout Timeout limit for request in seconds |
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149 | * @return array|false Assoc array of API response, decoded from JSON |
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150 | */ |
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151 | public function patch($method, $args = array(), $timeout = self::TIMEOUT) |
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152 | { |
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153 | return $this->makeRequest('patch', $method, $args, $timeout); |
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154 | } |
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155 | |||
156 | /** |
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157 | * Make an HTTP POST request - for creating and updating items |
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158 | * @param string $method URL of the API request method |
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159 | * @param array $args Assoc array of arguments (usually your data) |
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160 | * @param int $timeout Timeout limit for request in seconds |
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161 | * @return array|false Assoc array of API response, decoded from JSON |
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162 | */ |
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163 | public function post($method, $args = array(), $timeout = self::TIMEOUT) |
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164 | { |
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165 | return $this->makeRequest('post', $method, $args, $timeout); |
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166 | } |
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167 | |||
168 | /** |
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169 | * Make an HTTP PUT request - for creating new items |
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170 | * @param string $method URL of the API request method |
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171 | * @param array $args Assoc array of arguments (usually your data) |
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172 | * @param int $timeout Timeout limit for request in seconds |
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173 | * @return array|false Assoc array of API response, decoded from JSON |
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174 | */ |
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175 | public function put($method, $args = array(), $timeout = self::TIMEOUT) |
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176 | { |
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177 | return $this->makeRequest('put', $method, $args, $timeout); |
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178 | } |
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179 | |||
180 | /** |
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181 | * Performs the underlying HTTP request. Not very exciting. |
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182 | * @param string $http_verb The HTTP verb to use: get, post, put, patch, delete |
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183 | * @param string $method The API method to be called |
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184 | * @param array $args Assoc array of parameters to be passed |
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185 | * @param int $timeout |
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186 | * @return array|false Assoc array of decoded result |
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187 | * @throws \Exception |
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188 | */ |
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189 | private function makeRequest($http_verb, $method, $args = array(), $timeout = self::TIMEOUT) |
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190 | { |
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191 | if (!function_exists('curl_init') || !function_exists('curl_setopt')) { |
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192 | throw new \Exception("cURL support is required, but can't be found."); |
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193 | } |
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194 | |||
195 | $url = $this->api_endpoint . '/' . $method; |
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196 | |||
197 | $response = $this->prepareStateForRequest($http_verb, $method, $url, $timeout); |
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198 | |||
199 | $ch = curl_init(); |
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200 | curl_setopt($ch, CURLOPT_URL, $url); |
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201 | curl_setopt($ch, CURLOPT_HTTPHEADER, array( |
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202 | 'Accept: application/vnd.api+json', |
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203 | 'Content-Type: application/vnd.api+json', |
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204 | 'Authorization: apikey ' . $this->api_key |
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205 | )); |
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206 | curl_setopt($ch, CURLOPT_USERAGENT, 'DrewM/MailChimp-API/3.0 (github.com/drewm/mailchimp-api)'); |
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207 | curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); |
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208 | curl_setopt($ch, CURLOPT_VERBOSE, true); |
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209 | curl_setopt($ch, CURLOPT_HEADER, true); |
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210 | curl_setopt($ch, CURLOPT_TIMEOUT, $timeout); |
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211 | curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, $this->verify_ssl); |
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212 | curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0); |
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213 | curl_setopt($ch, CURLOPT_ENCODING, ''); |
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214 | curl_setopt($ch, CURLINFO_HEADER_OUT, true); |
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215 | |||
216 | switch ($http_verb) { |
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217 | case 'post': |
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218 | curl_setopt($ch, CURLOPT_POST, true); |
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219 | $this->attachRequestPayload($ch, $args); |
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220 | break; |
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221 | |||
222 | case 'get': |
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223 | $query = http_build_query($args, '', '&'); |
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224 | curl_setopt($ch, CURLOPT_URL, $url . '?' . $query); |
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225 | break; |
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226 | |||
227 | case 'delete': |
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228 | curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'DELETE'); |
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229 | break; |
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230 | |||
231 | case 'patch': |
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232 | curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PATCH'); |
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233 | $this->attachRequestPayload($ch, $args); |
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234 | break; |
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235 | |||
236 | case 'put': |
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237 | curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PUT'); |
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238 | $this->attachRequestPayload($ch, $args); |
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239 | break; |
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240 | } |
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241 | |||
242 | $responseContent = curl_exec($ch); |
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243 | $response['headers'] = curl_getinfo($ch); |
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244 | curl_close($ch); |
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245 | |||
246 | $response = $this->setResponseState($response, $responseContent); |
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247 | $formattedResponse = $this->formatResponse($response); |
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248 | |||
249 | $this->determineSuccess($response, $formattedResponse, $timeout); |
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250 | |||
251 | return $formattedResponse; |
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252 | } |
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253 | |||
254 | private function prepareStateForRequest($http_verb, $method, $url, $timeout) |
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255 | { |
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256 | $this->last_error = ''; |
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257 | |||
258 | $this->request_successful = false; |
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259 | |||
260 | $this->last_response = array( |
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261 | 'headers' => null, // array of details from curl_getinfo() |
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262 | 'httpHeaders' => null, // array of HTTP headers |
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263 | 'body' => null // content of the response |
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264 | ); |
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265 | |||
266 | $this->last_request = array( |
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267 | 'method' => $http_verb, |
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268 | 'path' => $method, |
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269 | 'url' => $url, |
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270 | 'body' => '', |
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271 | 'timeout' => $timeout, |
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272 | ); |
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273 | |||
274 | return $this->last_response; |
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275 | } |
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276 | |||
277 | /** |
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278 | * Get the HTTP headers as an array of header-name => header-value pairs. |
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279 | * |
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280 | * The "Link" header is parsed into an associative array based on the |
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281 | * rel names it contains. The original value is available under |
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282 | * the "_raw" key. |
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283 | * |
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284 | * @param string $headersAsString |
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285 | * @return array |
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286 | */ |
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287 | private function getHeadersAsArray($headersAsString) |
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315 | |||
316 | /** |
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317 | * Extract all rel => URL pairs from the provided Link header value |
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318 | * |
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319 | * Mailchimp only implements the URI reference and relation type from |
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320 | * RFC 5988, so the value of the header is something like this: |
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321 | * |
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322 | * '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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323 | * |
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324 | * @param string $linkHeaderAsString |
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325 | * @return array |
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326 | */ |
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327 | private function getLinkHeaderAsArray($linkHeaderAsString) |
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339 | |||
340 | /** |
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341 | * Encode the data and attach it to the request |
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342 | * @param resource $ch cURL session handle, used by reference |
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343 | * @param array $data Assoc array of data to attach |
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344 | */ |
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345 | private function attachRequestPayload(&$ch, $data) |
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351 | |||
352 | /** |
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353 | * Decode the response and format any error messages for debugging |
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354 | * @param array $response The response from the curl request |
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355 | * @return array|false The JSON decoded into an array |
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356 | */ |
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357 | private function formatResponse($response) |
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367 | |||
368 | /** |
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369 | * Do post-request formatting and setting state from the response |
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370 | * @param array $response The response from the curl request |
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371 | * @param string $responseContent The body of the response from the curl request |
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372 | * * @return array The modified response |
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373 | */ |
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374 | private function setResponseState($response, $responseContent) |
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375 | { |
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376 | if ($responseContent === false) { |
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377 | $this->last_error = curl_error($ch); |
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378 | } else { |
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379 | |||
380 | $headerSize = $response['headers']['header_size']; |
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381 | |||
382 | $response['httpHeaders'] = $this->getHeadersAsArray(substr($responseContent, 0, $headerSize)); |
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392 | |||
393 | /** |
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394 | * Check if the response was successful or a failure. If it failed, store the error. |
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395 | * @param array $response The response from the curl request |
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396 | * @param array|false $formattedResponse The response body payload from the curl request |
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397 | * @param int $timeout The timeout supplied to the curl request. |
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398 | * @return bool If the request was successful |
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399 | */ |
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400 | private function determineSuccess($response, $formattedResponse, $timeout) |
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422 | |||
423 | /** |
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424 | * Find the HTTP status code from the headers or API response body |
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425 | * @param array $response The response from the curl request |
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426 | * @param array|false $formattedResponse The response body payload from the curl request |
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427 | * @return int HTTP status code |
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428 | */ |
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429 | private function findHTTPStatus($response, $formattedResponse) |
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441 | } |
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442 |
This check marks access to variables or properties that have not been declared yet. While PHP has no explicit notion of declaring a variable, accessing it before a value is assigned to it is most likely a bug.