先把Object、Component、Module三个核心搞清楚了在写实例
下面介绍一下Object -- Yii最基础的类，大多数类都继承了该类。常用的12个公共方法，有点类似于ThinkPHP里面的魔术方法。
<?php
/**
* @link http://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
namespace yii\base;
use Yii;
/**
* Object is the base class that implements the *property* feature.
* Object 是一个基础类，实现了属性的功能
*
* A property is defined by a getter method (e.g. `getLabel`), and/or a setter method (e.g. `setLabel`). For example,
* the following getter and setter methods define a property named `label`:
* 一个定义了 getter 方法和/或者 setter 方法的属性
*
* ~~~
* private $_label;
*
* public function getLabel()
* {
* return $this->_label;
* }
*
* public function setLabel($value)
* {
* $this->_label = $value;
* }
* ~~~
*
* Property names are *case-insensitive*.
* 属性名是大小写敏感的
*
* A property can be accessed like a member variable of an object. Reading or writing a property will cause the invocation
* of the corresponding getter or setter method. For example,
* 属性能够被当做对象的成员变量使用
*
* ~~~
* // equivalent to $label = $object->getLabel();
* $label = $object->label;
* // equivalent to $object->setLabel(‘abc‘);
* $object->label = ‘abc‘;
* ~~~
*
* 如果一个属性只有一个getter方法,没有setter方法,它被认为是“只读”。在这种情况下,尝试
* 修改属性值会导致一个异常.
*
* One can call [[hasProperty()]], [[canGetProperty()]] and/or [[canSetProperty()]] to check the existence of a property.
*
* Besides the property feature, Object also introduces an important object initialization life cycle. In particular,
* creating an new instance of Object or its derived class will involve the following life cycles sequentially:
*
* 1. 调用构造函数;
* 2. 根据给定的对象属性初始化配置;
* 3. init()调用的方法.
*
* In the above, both Step 2 and 3 occur at the end of the class constructor. It is recommended that
* you perform object initialization in the `init()` method because at that stage, the object configuration
* is already applied.
*
* In order to ensure the above life cycles, if a child class of Object needs to override the constructor,
* it should be done like the following:
*
* ~~~
* public function __construct($param1, $param2, ..., $config = [])
* {
* ...
* parent::__construct($config);
* }
* ~~~
*
* That is, a `$config` parameter (defaults to `[]`) should be declared as the last parameter
* of the constructor, and the parent implementation should be called at the end of the constructor.
*
* Yii最基础的类，大多数类都继承了该类
*
* @author Qiang Xue <[email protected]>
* @since 2.0
*/
class Object implements Configurable
{
/**
* Returns the fully qualified name of this class.
* 获取静态方法调用的类名。返回类的名称，如果不是在类中调用则返回 FALSE。
*
* @return string the fully qualified name of this class.
*/
public static function className()
{
// get_called_class -- 后期静态绑定（"Late Static Binding"）类的名称
// 就是用那个类调用的这个方法，就返回那个类，返回值中带有 namespace
return get_called_class();
}
/**
* Constructor.
* 默认实现做两件事::
*
* - 用给定的配置初始化对象的配置.
* - Call [[init()]].
*
* If this method is overridden in a child class, it is recommended that
*
* - the last parameter of the constructor is a configuration array, like `$config` here.
* - call the parent implementation at the end of the constructor.
*
* @param array $config name-value pairs that will be used to initialize the object properties
*/
public function __construct($config = [])
{
// 根据 $config 内容初始化该对象
if (!empty($config)) {
Yii::configure($this, $config);
}
// 调用 init() 方法，继承该类的类可以重写 init 方法，用于初始化
$this->init();
}
/**
* Initializes the object.
* 初始化对象
* This method is invoked at the end of the constructor after the object is initialized with the
* given configuration.
*/
public function init()
{
}
/**
* 返回一个对象属性的值.
* 不要直接调用这个方法,因为它是一个PHP魔术方法
* will be implicitly called when executing `$value = $object->property;`.
*
* 魔术方法，实现 getter
*
* @param string $name the property name
* @return mixed the property value
* @throws UnknownPropertyException if the property is not defined
* @throws InvalidCallException if the property is write-only
* @see __set()
*/
public function __get($name)
{
$getter = ‘get‘ . $name;
if (method_exists($this, $getter)) {
// 对象存在 $getter 方法，就直接调用
return $this->$getter();
} elseif (method_exists($this, ‘set‘ . $name)) {
// 如果存在 ‘set‘ . $name 方法，就认为该属性是只写的
throw new InvalidCallException(‘Getting write-only property: ‘ . get_class($this) . ‘::‘ . $name);
} else {
// 否则认为该属性不存在
throw new UnknownPropertyException(‘Getting unknown property: ‘ . get_class($this) . ‘::‘ . $name);
}
}
/**
* 设置对象的属性值.
*
* 不要直接调用这个方法,因为它是一个PHP魔术方法
* will be implicitly called when executing `$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) . ‘::‘ . $name);
}
}
/**
* Checks if the named property is set (not null).
* 检查指定的属性设置(非空)。
* Do not call this method directly as it is a PHP magic method that
* will be implicitly called when executing `isset($object->property)`.
*
* 注意,如果没有定义的属性,将返回false.
*
* 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;
}
}
/**
* 对象属性设置为null.
*
* Do not call this method directly as it is a PHP magic method that
* will be implicitly called when executing `unset($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);
}
}
/**
* 调用指定的方法而不是一个类方法.
*
* 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) . "::$name()");
}
/**
* 返回一个值指示是否定义属性.
* A property is defined if:
*
* - the class has a getter or setter method associated with the specified name
* (in this case, property name is case-insensitive);
* - the class has a member variable with the specified name (when `$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);
}
/**
* 返回一个值指示是否可以读取属性.
* 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 $checkVars whether to treat member variables as properties
* @return boolean whether the property can be read
* @see canSetProperty()
*/
public function canGetProperty($name, $checkVars = true)
{
// property_exists — 检查对象或类是否具有该属性
return method_exists($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);
*
* 检查对象或类是否能够设置 $name 属性，如果 $checkVars 为 true，则不局限于是否有 setter
*
* @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);
}
/**
* 返回一个值指示是否定义了一个方法.
*
* The default implementation is a call to php function `method_exists()`.
* You may override this method when you implemented the php magic method `__call()`.
*
* 检查对象或类是否具有 $name 方法
*
* @param string $name the method name
* @return boolean 是否定义的方法
*/
public function hasMethod($name)
{
return method_exists($this, $name);
}
}
时间： 2024-08-05 09:00:07