Qiang Xue
13 years ago
13 changed files with 376 additions and 258 deletions
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<?php |
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/** |
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* Object class file. |
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* |
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* @link http://www.yiiframework.com/ |
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* @copyright Copyright © 2008-2012 Yii Software LLC |
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* @license http://www.yiiframework.com/license/ |
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*/ |
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|
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namespace yii\base; |
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|
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/** |
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* Object is the base class that implements the *property* feature. |
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* |
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* A property is defined by a getter method (e.g. `getLabel`), |
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* and/or a setter method (e.g. `setLabel`). For example, the following |
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* getter and setter methods define a property named `label`: |
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* |
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* ~~~ |
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* private $_label; |
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* |
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* public function getLabel() |
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* { |
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* return $this->_label; |
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* } |
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* |
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* public function setLabel($value) |
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* { |
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* $this->_label = $value; |
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* } |
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* ~~~ |
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* |
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* A property can be accessed like a member variable of an object. |
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* Reading or writing a property will cause the invocation of the corresponding |
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* getter or setter method. For example, |
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* |
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* ~~~ |
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* // equivalent to $label = $object->getLabel(); |
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* $label = $object->label; |
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* // equivalent to $object->setLabel('abc'); |
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* $object->label = 'abc'; |
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* ~~~ |
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* |
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* If a property only has a getter method and has no setter method, it is |
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* considered as *read-only*. In this case, trying to modify the property value |
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* will cause an exception. |
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* |
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* Property names are *case-insensitive*. |
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* |
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* One can call [[hasProperty]], [[canGetProperty]] and/or [[canSetProperty]] |
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* to check the existence of a property. |
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* |
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* Besides the property feature, the Object class defines a static method |
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* [[create]] which provides a convenient alternative way of creating a new |
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* object instance. |
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* |
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* The Object class also defines the [[evaluateExpression]] method so that a PHP |
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* expression or callback can be dynamically evaluated within the context of an object. |
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* |
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* @author Qiang Xue <qiang.xue@gmail.com> |
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* @since 2.0 |
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*/ |
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class Object |
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{ |
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/** |
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* Returns the value of a object property. |
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* |
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* Do not call this method directly as it is a PHP magic method that |
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* will be implicitly called when executing `$value = $object->property;`. |
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* @param string $name the property name |
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* @return mixed the property value, event handlers attached to the event, |
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* the named behavior, or the value of a behavior's property |
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* @throws Exception if the property is not defined |
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* @see __set |
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*/ |
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public function __get($name) |
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{ |
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$getter = 'get' . $name; |
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if (method_exists($this, $getter)) { |
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return $this->$getter(); |
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} |
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throw new Exception('Getting unknown property: ' . get_class($this) . '.' . $name); |
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} |
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|
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/** |
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* Sets value of a object property. |
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* |
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* Do not call this method directly as it is a PHP magic method that |
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* will be implicitly called when executing `$object->property = $value;`. |
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* @param string $name the property name or the event name |
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* @param mixed $value the property value |
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* @throws Exception if the property is not defined or read-only. |
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* @see __get |
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*/ |
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public function __set($name, $value) |
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{ |
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$setter = 'set' . $name; |
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if (method_exists($this, $setter)) { |
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return $this->$setter($value); |
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} |
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if (method_exists($this, 'get' . $name)) { |
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throw new Exception('Setting read-only property: ' . get_class($this) . '.' . $name); |
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} else { |
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throw new Exception('Setting unknown property: ' . get_class($this) . '.' . $name); |
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} |
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} |
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|
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/** |
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* Checks if the named property is set (not null). |
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* |
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* Do not call this method directly as it is a PHP magic method that |
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* will be implicitly called when executing `isset($object->property)`. |
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* |
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* Note that if the property is not defined, false will be returned. |
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* @param string $name the property name or the event name |
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* @return boolean whether the named property is set (not null). |
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*/ |
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public function __isset($name) |
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{ |
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$getter = 'get' . $name; |
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if (method_exists($this, $getter)) { // property is not null |
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return $this->$getter() !== null; |
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} |
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return false; |
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} |
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|
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/** |
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* Sets a object property to be null. |
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* |
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* Do not call this method directly as it is a PHP magic method that |
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* will be implicitly called when executing `unset($object->property)`. |
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* |
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* Note that if the property is not defined, this method will do nothing. |
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* If the property is read-only, it will throw an exception. |
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* @param string $name the property name |
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* @throws Exception if the property is read only. |
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*/ |
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public function __unset($name) |
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{ |
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$setter = 'set' . $name; |
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if (method_exists($this, $setter)) { // write property |
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$this->$setter(null); |
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} elseif (method_exists($this, 'get' . $name)) { |
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throw new Exception('Unsetting read-only property: ' . get_class($this) . '.' . $name); |
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} |
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} |
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|
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/** |
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* Returns a value indicating whether a property is defined. |
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* A property is defined if there is a getter or setter method |
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* defined in the class. Note that property names are case-insensitive. |
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* @param string $name the property name |
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* @return boolean whether the property is defined |
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* @see canGetProperty |
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* @see canSetProperty |
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*/ |
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public function hasProperty($name) |
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{ |
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return $this->canGetProperty($name) || $this->canSetProperty($name); |
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} |
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|
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/** |
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* Returns a value indicating whether a property can be read. |
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* A property can be read if the class has a getter method |
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* for the property name. Note that property name is case-insensitive. |
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* @param string $name the property name |
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* @return boolean whether the property can be read |
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* @see canSetProperty |
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*/ |
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public function canGetProperty($name) |
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{ |
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return method_exists($this, 'get' . $name); |
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} |
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|
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/** |
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* Returns a value indicating whether a property can be set. |
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* A property can be written if the class has a setter method |
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* for the property name. Note that property name is case-insensitive. |
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* @param string $name the property name |
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* @return boolean whether the property can be written |
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* @see canGetProperty |
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*/ |
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public function canSetProperty($name) |
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{ |
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return method_exists($this, 'set' . $name); |
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} |
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|
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/** |
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* Evaluates a PHP expression or callback under the context of this object. |
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* |
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* Valid PHP callback can be class method name in the form of |
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* array(ClassName/Object, MethodName), or anonymous function. |
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* |
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* If a PHP callback is used, the corresponding function/method signature should be |
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* |
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* ~~~ |
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* function foo($param1, $param2, ..., $object) { ... } |
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* ~~~ |
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* |
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* where the array elements in the second parameter to this method will be passed |
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* to the callback as `$param1`, `$param2`, ...; and the last parameter will be the object itself. |
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* |
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* If a PHP expression is used, the second parameter will be "extracted" into PHP variables |
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* that can be directly accessed in the expression. |
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* See [PHP extract](http://us.php.net/manual/en/function.extract.php) |
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* for more details. In the expression, the object can be accessed using `$this`. |
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* |
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* @param mixed $_expression_ a PHP expression or PHP callback to be evaluated. |
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* @param array $_data_ additional parameters to be passed to the above expression/callback. |
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* @return mixed the expression result |
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*/ |
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public function evaluateExpression($_expression_, $_data_=array()) |
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{ |
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if (is_string($_expression_)) { |
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extract($_data_); |
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return eval('return ' . $_expression_ . ';'); |
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} else { |
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$_data_[] = $this; |
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return call_user_func_array($_expression_, $_data_); |
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} |
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} |
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|
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/** |
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* Creates a new object instance. |
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* |
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* This method calls [[\Yii::create]] to create the new object instance. |
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* |
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* This method differs from the PHP `new` operator in that it does the following |
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* steps to create a new object instance: |
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* |
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* - Call class constructor (same the `new` operator); |
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* - Initialize the object properties using the name-value pairs given as the |
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* last parameter to this method; |
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* - Call [[Initable::init|init]] if the class implements [[Initable]]. |
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* |
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* Parameters passed to this method will be used as the parameters to the object |
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* constructor. |
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* |
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* Additionally, one can pass in an associative array as the last parameter to |
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* this method. This method will treat the array as name-value pairs that initialize |
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* the corresponding object properties. For example, |
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* |
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* ~~~ |
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* class Foo extends \yii\base\Object |
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* { |
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* public $c; |
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* public function __construct($a, $b) |
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* { |
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* ... |
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* } |
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* } |
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* |
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* $model = Foo::create(1, 2, array('c' => 3)); |
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* // which is equivalent to the following lines: |
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* $model = new Foo(1, 2); |
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* $model->c = 3; |
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* ~~~ |
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* |
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* @return object the created object |
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* @throws Exception if the configuration is invalid. |
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*/ |
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public static function create() |
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{ |
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$class = '\\' . get_called_class(); |
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if (($n = func_num_args()) > 0) { |
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$args = func_get_args(); |
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if (is_array($args[$n-1])) { |
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// the last parameter could be configuration array |
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$method = new \ReflectionMethod($class, '__construct'); |
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if ($method->getNumberOfParameters()+1 == $n) { |
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$config = $args[$n-1]; |
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array_pop($args); |
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} |
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} |
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$config['class'] = $class; |
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array_unshift($args, $config); |
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return call_user_func_array('\Yii::create', $args); |
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} else { |
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return \Yii::create($class); |
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} |
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} |
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} |
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