Complex classes like Amplitude 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 Amplitude, and based on these observations, apply Extract Interface, too.
1 | <?php |
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4 | class Amplitude |
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5 | { |
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6 | const AMPLITUDE_API_URL = 'https://api.amplitude.com/httpapi'; |
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7 | |||
8 | const EXCEPTION_MSG_NO_API_KEY = 'API Key is required to log an event'; |
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9 | const EXCEPTION_MSG_NO_EVENT_TYPE = 'Event Type is required to log or queue an event'; |
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10 | const EXCEPTION_MSG_NO_USER_OR_DEVICE = 'Either user_id or device_id required to log an event'; |
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11 | |||
12 | /** |
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13 | * The API key to use for all events generated by this instance |
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14 | * |
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15 | * @var string |
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16 | */ |
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17 | protected $apiKey; |
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18 | |||
19 | /** |
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20 | * The event that will be used for the next event being tracked |
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21 | * |
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22 | * @var \Zumba\Amplitude\Event |
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23 | */ |
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24 | protected $event; |
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25 | |||
26 | /** |
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27 | * The user ID to use for events generated by this instance |
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28 | * |
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29 | * @var string |
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30 | */ |
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31 | protected $userId; |
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32 | |||
33 | /** |
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34 | * The user data to set on the next event logged to Amplitude |
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35 | * |
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36 | * @var array |
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37 | */ |
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38 | protected $userProperties = []; |
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39 | |||
40 | /** |
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41 | * The device ID to use for events generated by this instance |
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42 | * |
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43 | * @var string |
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44 | */ |
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45 | protected $deviceId; |
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46 | |||
47 | /** |
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48 | * Queue of events, used to allow generating events that might happen prior to amplitude being fully initialized |
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49 | * |
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50 | * @var \Zumba\Amplitude\Event[] |
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51 | */ |
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52 | protected $queue = []; |
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53 | |||
54 | /** |
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55 | * Flag for if user is opted out of tracking |
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56 | * |
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57 | * @var boolean |
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58 | */ |
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59 | protected $optOut = false; |
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60 | |||
61 | /** |
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62 | * Flag for if should save the last HTTP response for debugging purposes |
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63 | * |
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64 | * @var boolean True to enable saving the last response |
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65 | */ |
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66 | protected $debugResponse = false; |
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67 | |||
68 | /** |
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69 | * Last response from logging event |
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70 | * |
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71 | * @var array|null |
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72 | */ |
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73 | protected $lastHttpResponse; |
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74 | |||
75 | /** |
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76 | * Array of Amplitude instances |
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77 | * |
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78 | * @var \Zumba\Amplitude\Amplitude[] |
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79 | */ |
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80 | private static $instances = []; |
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81 | |||
82 | /** |
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83 | * Singleton to get named instance |
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84 | * |
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85 | * Using this is optional, it depends on the use-case if it is better to use a singleton instance or just create |
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86 | * a new object directly. |
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87 | * |
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88 | * Useful if want to possibly send multiple events for the same user in a single page load, or even keep track |
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89 | * of multiple named instances, each could track to it's own api key and/or user/device ID. |
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90 | * |
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91 | * Each instance maintains it's own: |
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92 | * - API Key |
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93 | * - User ID |
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94 | * - Device ID |
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95 | * - User Properties |
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96 | * - Event Queue (if events are queued before the amplitude instance is initialized) |
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97 | * - Event object - for the next event that will be sent or queued |
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98 | * - Opt out status |
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99 | * |
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100 | * @param string $instanceName Optional, can use to maintain multiple singleton instances of amplitude, each with |
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101 | * it's own API key set |
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102 | * @return \Zumba\Amplitude\Amplitude |
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103 | */ |
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104 | public static function getInstance($instanceName = 'default') |
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111 | |||
112 | /** |
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113 | * Constructor, optionally sets the api key |
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114 | * |
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115 | * @param string $apiKey |
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116 | */ |
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117 | public function __construct($apiKey = null) |
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123 | |||
124 | /** |
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125 | * Initialize amplitude |
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126 | * |
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127 | * This lets you set the api key, and optionally the user ID. |
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128 | * |
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129 | * @param string $apiKey Amplitude API key |
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130 | * @param string $userId |
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131 | * @return \Zumba\Amplitude\Amplitude |
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132 | */ |
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133 | public function init($apiKey, $userId = null) |
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141 | |||
142 | /** |
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143 | * Log any events that were queued before amplitude was initialized |
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144 | * |
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145 | * Note that api key, and either the user ID or device ID need to be set prior to calling this. |
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146 | * |
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147 | * @return \Zumba\Amplitude\Amplitude |
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148 | * @throws \LogicException |
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149 | */ |
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150 | public function logQueuedEvents() |
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162 | |||
163 | /** |
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164 | * Clear out all events in the queue, without sending them to amplitude |
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165 | * |
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166 | * @return \Zumba\Amplitude\Amplitude |
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167 | */ |
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168 | public function resetQueue() |
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173 | |||
174 | /** |
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175 | * Gets the event that will be used for the next event logged by call to logEvent() or queueEvent() |
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176 | * |
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177 | * You can also pass in an event or array of event properties. If you pass in an event, it will be set as the |
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178 | * event to be used for the next call to queueEvent() or logEvent() |
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179 | * |
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180 | * @param null|array|\Zumba\Amplitude\Event Can pass in an event to set as the next event to run, or array to set |
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181 | * properties on that event |
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182 | * @return \Zumba\Amplitude\Event |
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183 | */ |
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184 | public function event($event = null) |
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198 | |||
199 | /** |
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200 | * Resets the event currently in the process of being set up (what is returned by event()) |
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201 | * |
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202 | * @return \Zumba\Amplitude\Amplitude |
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203 | */ |
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204 | public function resetEvent() |
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209 | |||
210 | /** |
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211 | * Log an event immediately |
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212 | * |
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213 | * Requires amplitude is already initialized and user ID or device ID is set. If need to wait until amplitude |
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214 | * is initialized, use queueEvent() method instead. |
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215 | * |
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216 | * Can either pass in information to be logged, or can set up the Event object before hand, see the event() |
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217 | * method for more information |
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218 | * |
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219 | * @param string $eventType Required if not set on event object prior to calling this |
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220 | * @param array $eventProperties Optional, properties to set on event |
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221 | * @return \Zumba\Amplitude\Amplitude |
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222 | * @throws \LogicException Thorws exception if any of the requirments are not met, such as api key set |
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223 | */ |
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224 | public function logEvent($eventType = '', array $eventProperties = []) |
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253 | |||
254 | /** |
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255 | * Set the persistent data on the event object |
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256 | * |
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257 | * @return void |
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258 | */ |
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259 | protected function setPersistentEventData() |
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273 | |||
274 | /** |
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275 | * Log or queue the event, depending on if amplitude instance is already set up or not |
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276 | * |
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277 | * Note that this is an internal queue, the queue is lost between page loads. |
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278 | * |
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279 | * This functions identically to logEvent, with the exception that if Amplitude is not yet set up, it queues the |
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280 | * event to be logged later (during same page load). |
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281 | * |
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282 | * If the API key, and either user ID or device ID are already set in the amplitude instance, and there is not |
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283 | * already events in the queue that have not been run, this will log the event immediately. Note that having |
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284 | * the userId or deviceId set on the event itself does not affect if it queues the event or not, only if set on |
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285 | * the Amplitude instance. |
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286 | * |
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287 | * Otherwise it will queue the event, and will be run after the amplitude instance is initialized and |
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288 | * logQueuedEvents() method is run |
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289 | * |
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290 | * @param string $eventType |
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291 | * @param array $eventProperties |
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292 | * @return \Zumba\Amplitude\Amplitude |
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293 | * @throws \LogicException |
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294 | */ |
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295 | public function queueEvent($eventType = '', array $eventProperties = []) |
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317 | |||
318 | /** |
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319 | * Set the user ID for future events logged |
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320 | * |
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321 | * Any set with this will take precedence over any set on the Event object |
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322 | * |
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323 | * @param string $userId |
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324 | * @return \Zumba\Amplitude\Amplitude |
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325 | */ |
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326 | public function setUserId($userId) |
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331 | |||
332 | /** |
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333 | * Set the device ID for future events logged |
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334 | * |
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335 | * Any set with this will take precedence over any set on the Event object |
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336 | * |
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337 | * @param string $deviceId |
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338 | * @return \Zumba\Amplitude\Amplitude |
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339 | */ |
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340 | public function setDeviceId($deviceId) |
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345 | |||
346 | /** |
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347 | * Set the user properties, will be sent with the next event sent to Amplitude |
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348 | * |
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349 | * Any set with this will take precedence over any set on the Event object |
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350 | * |
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351 | * If no events are logged, it will not get sent to Amplitude |
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352 | * |
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353 | * @param array $userProperties |
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354 | */ |
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355 | public function setUserProperties(array $userProperties) |
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360 | |||
361 | /** |
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362 | * Resets user properties added with setUserProperties() if they have not already been sent in an event to Amplitude |
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363 | * |
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364 | * @return \Zumba\Amplitude\Amplitude |
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365 | */ |
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366 | public function resetUserProperties() |
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371 | |||
372 | /** |
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373 | * Check if there are events in the queue that have not been sent |
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374 | * |
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375 | * @return boolean |
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376 | */ |
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377 | public function hasQueuedEvents() |
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381 | |||
382 | /** |
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383 | * Resets all user information |
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384 | * |
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385 | * This resets the user ID, device ID previously set using setUserId or setDeviceId. |
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386 | * |
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387 | * If additional information was previously set using setUserProperties() method, and the event has not already |
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388 | * been sent to Amplitude, it will reset that information as well. |
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389 | * |
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390 | * Does not reset user information if set manually on an individual event in the queue. |
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391 | * |
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392 | * @return \Zumba\Amplitude\Amplitude |
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393 | */ |
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394 | public function resetUser() |
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401 | |||
402 | /** |
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403 | * Set opt out for the current user. |
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404 | * |
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405 | * If set to true, will not send any future events to amplitude for this amplitude instance. |
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406 | * |
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407 | * @param boolean $optOut |
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408 | * @return \Zumba\Amplitude\Amplitude |
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409 | */ |
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410 | public function setOptOut($optOut) |
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415 | |||
416 | /** |
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417 | * Getter for currently set api key |
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418 | * |
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419 | * @return string|null |
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420 | */ |
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421 | public function getApiKey() |
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425 | |||
426 | /** |
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427 | * Getter for currently set user ID |
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428 | * |
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429 | * @return string|null |
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430 | */ |
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431 | public function getUserId() |
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435 | |||
436 | /** |
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437 | * Getter for currently set device ID |
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438 | * |
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439 | * @return string|null |
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440 | */ |
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441 | public function getDeviceId() |
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445 | |||
446 | /** |
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447 | * Getter for all currently set user properties, that will be automatically sent on next Amplitude event |
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448 | * |
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449 | * Once the properties have been sent in an Amplitude event, they will be cleared. |
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450 | * |
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451 | * @return array |
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452 | */ |
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453 | public function getUserProperties() |
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457 | |||
458 | /** |
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459 | * Get the current value for opt out. |
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460 | * |
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461 | * @return boolean |
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462 | */ |
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463 | public function getOptOut() |
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467 | |||
468 | /** |
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469 | * Sets flag for debugging responses |
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470 | * |
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471 | * See getLastHttpResponse() for getting the last response |
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472 | * |
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473 | * @param boolean $debug If true, will keep track of last response from Amplitude for debugging purposes |
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474 | * @return \Zumba\Amplitude\Amplitude |
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475 | */ |
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476 | public function setDebugResponse($debug) |
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481 | |||
482 | /** |
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483 | * Gets current flag value for whether to record the last response from Amplitude when sending events |
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484 | * |
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485 | * @return boolean |
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486 | */ |
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487 | public function getDebugResponse() |
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491 | |||
492 | /** |
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493 | * For debugging new connections - returns array with details of the last log, or null if no logs sent. |
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494 | * |
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495 | * Returned array will be in the format: |
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496 | * <code> |
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497 | * $lastHttpResponse = [ |
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498 | * 'code' => 100, // HTTP Response Code |
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499 | * 'message' => 'success', // Response received |
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500 | * 'curl_error' => '...', // Only set if there was some error when attempting to send the request |
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501 | * ]; |
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502 | * </code> |
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503 | * |
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504 | * @return array|null Returns null if debug response is disabled, or if no events sent to Amplitude yet |
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505 | */ |
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506 | public function getLastHttpResponse() |
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510 | |||
511 | /** |
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512 | * Send the event currently set in $this->event to amplitude |
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513 | * |
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514 | * Requres $this->event and $this->apiKey to be set, otherwise it throws an exception. |
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515 | * |
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516 | * @return void |
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517 | * @throws \InternalErrorException If event or api key not set |
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518 | */ |
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519 | protected function sendEvent() |
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547 | } |
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548 |