YII2框架分析2: Object类

class Object

Object类实现了类的多种特性

    public function __get($name)
    {
$getter = 'get' . $name;
if (method_exists($this, $getter)) {
return $this->$getter();
        } elseif (method_exists($this, 'set' . $name)) {
throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);
        } else {
throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);
        }
    }

php魔术方法，当试图读取一个对象并不存在的属性的时候被调用。

e.g. $value = $object->property的时候，检查$object是否有getProperty方法，如果有，则返回getProperty()，如果没有，检查setProperty()方法是否存在。如果存在，抛出只写异常。如不存在，抛出未知属性异常。

 

    public function __set($name, $value)
    {
$setter = 'set' . $name;
if (method_exists($this, $setter)) {
$this->$setter($value);
        } elseif (method_exists($this, 'get' . $name)) {
throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
        } else {
throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
        }
    }

php魔术方法，当时图写入一个对象不存在的属性的时候被调用。

e.g. $object->property = $value的时候，检查$object是否有setProperty方法，如果有，则调用$object->setProperty($value)方法，没有检查是否有getProperty方法。如果存在，抛出只读异常。否则，抛出未知属性异常。

 

    public function __isset($name)
    {
$getter = 'get' . $name;
if (method_exists($this, $getter)) {
return $this->$getter() !== null;
        } else {
return false;
        }
    }

php魔术方法，isset($object->property)的时候调用。判断是否存在 $object->getProperty方法。

 

    public function __unset($name)
    {
$setter = 'set' . $name;
if (method_exists($this, $setter)) {
$this->$setter(null);
        } elseif (method_exists($this, 'get' . $name)) {
throw new InvalidCallException('Unsetting read-only property: ' . get_class($this) . '::' . $name);
        }
    }

php魔术方法，unset($object->property)的时候调用。如果存在$object->setProperty方法，则调用$object->setProperty(null)。如不存在，抛出InvalidCallException异常。

 

    /**
     * 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.
     * @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()");
    }

php魔术方法，执行一个未知方法的时候调用，直接抛出UnknownMethodException异常。

 

    /**
     * Returns a value indicating whether a method is defined.
     *
     * The default implementation is a call to php function `method_exists()`.
     * You may override this method when you implemented the php magic method `__call()`.
     * @param string $name the property name
     * @return boolean whether the property is defined
*/
public function hasMethod($name)
    {
return method_exists($this, $name);
    }

方法是否存在

 

    /**
     * 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);
     *
     * @param string $name the property name
     * @param boolean $checkVars whether to treat member variables as properties
     * @return boolean whether the property can be read
     * @see canSetProperty()
*/
public function canGetProperty($name, $checkVars = true)
    {
return method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name);
    }

/**
     * Returns a value indicating whether a property can be set.
     * A property is writable if:
     *
     * - the class has a 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);
     *
     * @param string $name the property name
     * @param boolean $checkVars whether to treat member variables as properties
     * @return boolean whether the property can be written
     * @see canGetProperty()
*/
public function canSetProperty($name, $checkVars = true)
    {
return method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name);
    }

判断getProperty(setProperty)方法是否存在。$checkVars参数为是否使用property_exists检查属性是否存在，默认为true。

 

    /**
     * Returns a value indicating whether a property is defined.
     * 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);
     *
     * @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);
    }

检查属性是否存在，可读或可写。