<?php
/**
* Sets value of an object property.
* 设置对象的属性值。
* Do not call this method directly as it is a PHP magic method that
* will be implicitly called when executing `$object->property = $value;`.
*
* 魔术方法，实现 setter
*
* @param string $name the property name or the event name
* @param mixed $value the property value
* @throws UnknownPropertyException if the property is not defined
* @throws InvalidCallException if the property is read-only
* @see __get()
*/
public function __set($name, $value)
{
$setter = 'set' . $name;
if (method_exists($this, $setter)) {
// 对象存在 $setter 方法，就直接调用
$this->$setter($value);
} elseif (method_exists($this, 'get' . $name)) {
// 如果存在 'get' . $name 方法，就认为该属性是只读的
throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
} else {
// 否则认为该属性不存在
throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
}
}
/**
* Checks if the named property is set (not null).
* 检查属性是否被设置
*
* Do not call this method directly as it is a PHP magic method that
* will be implicitly called when executing `isset($object->property)`.
* 不要直接调用这个方法,因为它是一个PHP魔术方法呢，调用执行`isset($object->property)`。
* Note that if the property is not defined, false will be returned.
*
* 魔术方法，实现 isset，基于 getter 实现，有 getter 方法的属性才算存在
*
* @param string $name the property name or the event name
* @return boolean whether the named property is set (not null).
*/
public function __isset($name)
{
$getter = 'get' . $name;
if (method_exists($this, $getter)) {
// 有 $getter 方法且获取的值不为 null，才认为该属性存在
return $this->$getter() !== null;
} else {
return false;
}
}
/**
* Sets an object property to null.
*
* Do not call this method directly as it is a PHP magic method that
* will be implicitly called when executing `unset($object->property)`.
* 不要直接调用这个方法,因为它是一个PHP魔术方法呢，调用执行`isset($object->property)`。
* Note that if the property is not defined, this method will do nothing.
* If the property is read-only, it will throw an exception.
*
* 魔术方法，实现 unset，基于 setter 实现，有 setter 方法的属性才能 unset 掉
*
* @param string $name the property name
* @throws InvalidCallException if the property is read only.
*/
public function __unset($name)
{
$setter = 'set' . $name;
if (method_exists($this, $setter)) {
// 通过 $setter 方法，将它设置为 null
$this->$setter(null);
} elseif (method_exists($this, 'get' . $name)) {
// 如果存在 'get' . $name 方法，就认为该属性是只读的
throw new InvalidCallException('Unsetting read-only property: ' . get_class($this) . '::' . $name);
}
}
/**
* Calls the named method which is not a class method.
*
* Do not call this method directly as it is a PHP magic method that
* will be implicitly called when an unknown method is being invoked.
* 重写了__call（）方法，在调用不存在的方法时会调用此方法，抛出异常
* @param string $name the method name
* @param array $params method parameters
* @throws UnknownMethodException when calling unknown method
* @return mixed the method return value
*/
public function __call($name, $params)
{
throw new UnknownMethodException('Calling unknown method: ' . get_class($this) .
"::$name()");
}
/**
* Returns a value indicating whether a property is defined.
* 返回一个值指示是否定义属性。
* A property is defined if:
*
* - the class has a getter or setter method associated with the specified name
* (in this case, property name is case-insensitive);
* - the class has a member variable with the specified name (when `$checkVars` is true);
*
* 检查对象或类是否具有 $name 属性，如果 $checkVars 为 true，则不局限于是否有 getter/setter
*
* @param string $name the property name
* @param boolean $checkVars whether to treat member variables as properties
* @return boolean whether the property is defined
* @see canGetProperty()
* @see canSetProperty()
*/
public function hasProperty($name, $checkVars = true)
{
return $this->canGetProperty($name, $checkVars) || $this->canSetProperty($name, false);
}
/**
* Returns a value indicating whether a property can be read.
* A property is readable if:
*
* - the class has a getter method associated with the specified name
* (in this case, property name is case-insensitive);
* - the class has a member variable with the specified name (when `$checkVars` is true);
*
* 检查对象或类是否能够获取 $name 属性，如果 $checkVars 为 true，则不局限于是否有 getter
*
* @param string $name the property name
* @param boolean $checkVars whether to treat member variables as properties
* @return boolean whether the property can be read
* @see canSetProperty()
