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1 | <?php |
2 | /* | |
3 | +--------------------------------------------------------------------+ | |
fee14197 | 4 | | CiviCRM version 5 | |
762dc04d | 5 | +--------------------------------------------------------------------+ |
8c9251b3 | 6 | | Copyright CiviCRM LLC (c) 2004-2018 | |
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7 | +--------------------------------------------------------------------+ |
8 | | This file is a part of CiviCRM. | | |
9 | | | | |
10 | | CiviCRM is free software; you can copy, modify, and distribute it | | |
11 | | under the terms of the GNU Affero General Public License | | |
12 | | Version 3, 19 November 2007 and the CiviCRM Licensing Exception. | | |
13 | | | | |
14 | | CiviCRM is distributed in the hope that it will be useful, but | | |
15 | | WITHOUT ANY WARRANTY; without even the implied warranty of | | |
16 | | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | | |
17 | | See the GNU Affero General Public License for more details. | | |
18 | | | | |
19 | | You should have received a copy of the GNU Affero General Public | | |
20 | | License and the CiviCRM Licensing Exception along | | |
21 | | with this program; if not, contact CiviCRM LLC | | |
22 | | at info[AT]civicrm[DOT]org. If you have questions about the | | |
23 | | GNU Affero General Public License or the licensing of CiviCRM, | | |
24 | | see the CiviCRM license FAQ at http://civicrm.org/licensing | | |
25 | +--------------------------------------------------------------------+ | |
26 | */ | |
27 | ||
28 | namespace Civi\Core\Event; | |
29 | ||
30 | /** | |
31 | * Class GenericHookEvent | |
32 | * @package Civi\API\Event | |
33 | * | |
34 | * The GenericHookEvent is used to expose all traditional hooks to the | |
35 | * Symfony EventDispatcher. | |
36 | * | |
37 | * The traditional notation for a hook is based on a function signature: | |
38 | * | |
39 | * function hook_civicrm_foo($bar, &$whiz, &$bang); | |
40 | * | |
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41 | * The notation for Symfony Events is based on a class with properties |
42 | * and methods. This requires some kind of mapping. `GenericHookEvent` | |
43 | * maps each parameter to a field (using magic methods): | |
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44 | * |
45 | * @code | |
0d681395 | 46 | * // Creating an event object. |
762dc04d | 47 | * $event = GenericHookEvent::create(array( |
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48 | * 'bar' => 'abc', |
49 | * 'whiz' => &$whiz, | |
50 | * 'bang' => &$bang, | |
51 | * ); | |
52 | * | |
53 | * // Accessing event properties. | |
54 | * echo $event->bar; | |
55 | * $event->whiz['array_field'] = 123; | |
56 | * $event->bang->objProperty = 'abcd'; | |
57 | * | |
58 | * // Dispatching an event. | |
762dc04d | 59 | * Civi::service('dispatcher')->dispatch('hook_civicrm_foo', $event); |
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60 | * @endCode |
61 | * | |
62 | * Design Discussion: | |
63 | * | |
64 | * 1. Implementing new event classes for every hook would produce a | |
65 | * large amount of boilerplate. Symfony Events have an interesting solution to | |
66 | * that problem: use `GenericEvent` instead of custom event classes. | |
67 | * `GenericHookEvent` is conceptually similar to `GenericEvent`, but it adds | |
68 | * support for (a) altering properties and (b) mapping properties to hook notation | |
69 | * (an ordered parameter list). | |
70 | * | |
71 | * 2. A handful of hooks define a return-value. The return-value is treated | |
72 | * as an array, and all the returned values are merged into one big array. | |
73 | * You can add and retrieve return-values using these methods: | |
74 | * | |
75 | * @code | |
76 | * $event->addReturnValues(array(...)); | |
77 | * foreach ($event->getReturnValues() as $retVal) { ... } | |
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78 | * @endCode |
79 | */ | |
80 | class GenericHookEvent extends \Symfony\Component\EventDispatcher\Event { | |
81 | ||
82 | /** | |
83 | * @var array | |
0d681395 | 84 | * Ex: array(0 => &$contactID, 1 => &$contentPlacement). |
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85 | */ |
86 | protected $hookValues; | |
87 | ||
88 | /** | |
89 | * @var array | |
90 | * Ex: array(0 => 'contactID', 1 => 'contentPlacement'). | |
91 | */ | |
92 | protected $hookFields; | |
93 | ||
94 | /** | |
95 | * @var array | |
96 | * Ex: array('contactID' => 0, 'contentPlacement' => 1). | |
97 | */ | |
98 | protected $hookFieldsFlip; | |
99 | ||
100 | /** | |
101 | * Some legacy hooks expect listener-functions to return a value. | |
102 | * OOP listeners may set the $returnValue. | |
103 | * | |
104 | * This field is not recommended for use in new hooks. The return-value | |
105 | * convention is not portable across different implementations of the hook | |
106 | * system. Instead, it's more portable to provide an alterable, named field. | |
107 | * | |
108 | * @var mixed | |
109 | * @deprecated | |
110 | */ | |
111 | private $returnValues = array(); | |
112 | ||
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113 | /** |
114 | * List of field names that are prohibited due to conflicts | |
115 | * in the class-hierarchy. | |
116 | * | |
117 | * @var array | |
118 | */ | |
119 | private static $BLACKLIST = array( | |
120 | 'name', | |
121 | 'dispatcher', | |
122 | 'propagationStopped', | |
123 | 'hookBlacklist', | |
124 | 'hookValues', | |
125 | 'hookFields', | |
126 | 'hookFieldsFlip', | |
127 | ); | |
128 | ||
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129 | /** |
130 | * Create a GenericHookEvent using key-value pairs. | |
131 | * | |
132 | * @param array $params | |
133 | * Ex: array('contactID' => &$contactID, 'contentPlacement' => &$contentPlacement). | |
134 | * @return \Civi\Core\Event\GenericHookEvent | |
135 | */ | |
136 | public static function create($params) { | |
137 | $e = new static(); | |
138 | $e->hookValues = array_values($params); | |
139 | $e->hookFields = array_keys($params); | |
140 | $e->hookFieldsFlip = array_flip($e->hookFields); | |
0fcad357 | 141 | self::assertValidHookFields($e->hookFields); |
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142 | return $e; |
143 | } | |
144 | ||
145 | /** | |
146 | * Create a GenericHookEvent using ordered parameters. | |
147 | * | |
148 | * @param array $hookFields | |
149 | * Ex: array(0 => 'contactID', 1 => 'contentPlacement'). | |
150 | * @param array $hookValues | |
151 | * Ex: array(0 => &$contactID, 1 => &$contentPlacement). | |
152 | * @return \Civi\Core\Event\GenericHookEvent | |
153 | */ | |
154 | public static function createOrdered($hookFields, $hookValues) { | |
155 | $e = new static(); | |
156 | if (count($hookValues) > count($hookFields)) { | |
157 | $hookValues = array_slice($hookValues, 0, count($hookFields)); | |
158 | } | |
159 | $e->hookValues = $hookValues; | |
160 | $e->hookFields = $hookFields; | |
161 | $e->hookFieldsFlip = array_flip($e->hookFields); | |
0fcad357 | 162 | self::assertValidHookFields($e->hookFields); |
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163 | return $e; |
164 | } | |
165 | ||
0fcad357 TO |
166 | /** |
167 | * @param array $fields | |
168 | * List of field names. | |
169 | */ | |
170 | private static function assertValidHookFields($fields) { | |
171 | $bad = array_intersect($fields, self::$BLACKLIST); | |
172 | if ($bad) { | |
173 | throw new \RuntimeException("Hook relies on conflicted field names: " | |
174 | . implode(', ', $bad)); | |
175 | } | |
176 | } | |
177 | ||
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178 | /** |
179 | * @return array | |
180 | * Ex: array(0 => &$contactID, 1 => &$contentPlacement). | |
181 | */ | |
182 | public function getHookValues() { | |
183 | return $this->hookValues; | |
184 | } | |
185 | ||
186 | /** | |
187 | * @return mixed | |
188 | * @deprecated | |
189 | */ | |
190 | public function getReturnValues() { | |
191 | return empty($this->returnValues) ? TRUE : $this->returnValues; | |
192 | } | |
193 | ||
194 | /** | |
195 | * @param mixed $fResult | |
196 | * @return GenericHookEvent | |
197 | * @deprecated | |
198 | */ | |
199 | public function addReturnValues($fResult) { | |
200 | if (!empty($fResult) && is_array($fResult)) { | |
201 | $this->returnValues = array_merge($this->returnValues, $fResult); | |
202 | } | |
203 | return $this; | |
204 | } | |
205 | ||
206 | /** | |
207 | * @inheritDoc | |
208 | */ | |
209 | public function &__get($name) { | |
210 | if (isset($this->hookFieldsFlip[$name])) { | |
211 | return $this->hookValues[$this->hookFieldsFlip[$name]]; | |
212 | } | |
213 | } | |
214 | ||
215 | /** | |
216 | * @inheritDoc | |
217 | */ | |
218 | public function __set($name, $value) { | |
219 | if (isset($this->hookFieldsFlip[$name])) { | |
220 | $this->hookValues[$this->hookFieldsFlip[$name]] = $value; | |
221 | } | |
222 | } | |
223 | ||
224 | /** | |
225 | * @inheritDoc | |
226 | */ | |
227 | public function __isset($name) { | |
228 | return isset($this->hookFieldsFlip[$name]) | |
229 | && isset($this->hookValues[$this->hookFieldsFlip[$name]]); | |
230 | } | |
231 | ||
232 | /** | |
233 | * @inheritDoc | |
234 | */ | |
235 | public function __unset($name) { | |
236 | if (isset($this->hookFieldsFlip[$name])) { | |
237 | // Unset while preserving order. | |
238 | $this->hookValues[$this->hookFieldsFlip[$name]] = NULL; | |
239 | } | |
240 | } | |
241 | ||
242 | /** | |
243 | * Determine whether the hook supports the given field. | |
244 | * | |
245 | * The field may or may not be empty. Use isset() or empty() to | |
246 | * check that. | |
247 | * | |
248 | * @param string $name | |
249 | * @return bool | |
250 | */ | |
251 | public function hasField($name) { | |
252 | return isset($this->hookFieldsFlip[$name]); | |
253 | } | |
254 | ||
255 | } |