继续了解组件Component.php
/**
* Returns a value indicating whether a property is defined for this component.
* 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 `$checkVars` is true);
* - an attached behavior has a property of the given name (when `$checkBehaviors` is true).
* 与 Object 中的方法类似，只是添加了是否检测行为的参数
* @param string $name the property name 属性名
* @param boolean $checkVars whether to treat member variables as properties
* @param boolean $checkBehaviors whether to treat behaviors' properties as properties of this component
* 是否将行为属性作为该组件的属性来对待
* @return boolean whether the property is defined 属性是否定义
* @see canGetProperty() 可读
* @see canSetProperty() 可设置
*/
public function hasProperty($name, $checkVars = true, $checkBehaviors = true)
{ // $checkVars 参数，用来检查对象是否具有该属性 （不是 getter 和 setter 定义出的属性）
//$checkBehaviors参数，用来设置是否检测behavior
return $this->canGetProperty($name, $checkVars, $checkBehaviors) || $this->canSetProperty($name, false, $checkBehaviors);
} /**
* Returns a value indicating whether a property can be read.
* A property can be read if:
*
* - the class has a getter method associated with the specified name
* (in this case, property name is case-insensitive);
* - the class has a member variable with the specified name (when `$checkVars` is true);
* - an attached behavior has a readable property of the given name (when `$checkBehaviors` is true).
* 检查对象或类是否能够获取 $name 属性
* @param string $name the property name 属性名
* @param boolean $checkVars whether to treat member variables as properties 是否将成员对象作为属性
* @param boolean $checkBehaviors whether to treat behaviors' properties as properties of this component
* 是否将成员属性作为该组件的属性
* @return boolean whether the property can be read 属性是否可读
* @see canSetProperty()
*/
public function canGetProperty($name, $checkVars = true, $checkBehaviors = true)
{
if (method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name)) {
// 存在 'get' . $name方法 或 存在该属性， 返回true
return true;
} elseif ($checkBehaviors) {
$this->ensureBehaviors();
foreach ($this->_behaviors as $behavior) {
// behavior 中存在名为 $name 的可读属性，认为该对象也存在 返回true
if ($behavior->canGetProperty($name, $checkVars)) {
return true;
}
}
}
return false;
} /**
* Returns a value indicating whether a property can be set.
* A property can be written if:
*
* - the class has a setter method associated with the specified name
* (in this case, property name is case-insensitive);
* - the class has a member variable with the specified name (when `$checkVars` is true);
* - an attached behavior has a writable property of the given name (when `$checkBehaviors` is true).
* 检查对象或类是否能够设置 $name 属性
* @param string $name the property name 属性名
* @param boolean $checkVars whether to treat member variables as properties 是否将成员变量作为属性
* @param boolean $checkBehaviors whether to treat behaviors' properties as properties of this component
* 是否将行为属性作为该组件的属性
* @return boolean whether the property can be written 属性是否可写
* @see canGetProperty()
*/
public function canSetProperty($name, $checkVars = true, $checkBehaviors = true)
{
if (method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name)) {
// 存在 'set' . $name方法 或 存在该属性， 返回true
return true;
} elseif ($checkBehaviors) {
$this->ensureBehaviors();
foreach ($this->_behaviors as $behavior) {
// behavior 中存在名为 $name 的可写属性，认为该对象也存在 返回true
if ($behavior->canSetProperty($name, $checkVars)) {
return true;
}
}
}
return false;
} /**
* Returns a value indicating whether a method is defined.
* A method is defined if:
*
* - the class has a method with the specified name
* - an attached behavior has a method with the given name (when `$checkBehaviors` is true).
* 检查对象或类是否具有 $name 方法
* @param string $name the property name
* @param boolean $checkBehaviors whether to treat behaviors' methods as methods of this component
* @return boolean whether the property is defined
*/
public function hasMethod($name, $checkBehaviors = true)
{
if (method_exists($this, $name)) {
return true;
} elseif ($checkBehaviors) {//标记是否 check behavior 中的方法
$this->ensureBehaviors();
foreach ($this->_behaviors as $behavior) {
// behavior 中存在名为 $name 的方法，就认为该方法也存在
if ($behavior->hasMethod($name)) {
return true;
}
}
}
return false;
} /**
* Returns a list of behaviors that this component should behave as.
* 定义该对象中要用到的 behavior
* Child classes may override this method to specify the behaviors they want to behave as.
* 可重写
* The return value of this method should be an array of behavior objects or configurations
* indexed by behavior names. A behavior configuration can be either a string specifying
* the behavior class or an array of the following structure:
*
* ~~~
* 'behaviorName' => [
* 'class' => 'BehaviorClass',
* 'property1' => 'value1',
* 'property2' => 'value2',
* ]
* ~~~
*
* Note that a behavior class must extend from [[Behavior]]. Behavior names can be strings
* or integers. If the former, they uniquely identify the behaviors. If the latter, the corresponding
* behaviors are anonymous and their properties and methods will NOT be made available via the component
* (however, the behaviors can still respond to the component's events).
* 行为名称可以是字符串或整数。如果是前者，他们是唯一确定的行为。如果是后者，相应的
* 行为是匿名的，它们的特性和方法将无法通过组件提供（仍然可以对组件的事件作出反应）
* Behaviors declared in this method will be attached to the component automatically (on demand).
* 在这种方法中声明的行为将自动连接到组件
* @return array the behavior configurations.
*/
public function behaviors()
{
return [];
} /**
* Returns a value indicating whether there is any handler attached to the named event.
* 判断 _events 中的一个事件是否具有事件处理程序
* @param string $name the event name 事件名
* @return boolean whether there is any handler attached to the event.
*/
public function hasEventHandlers($name)
{
$this->ensureBehaviors();
// 判断事件是否存在 $name 否则 调用Event类中的的方法判断是否有处理程序
return !empty($this->_events[$name]) || Event::hasHandlers($this, $name);
} /**
* Attaches an event handler to an event.
* 处理程序的事件
* The event handler must be a valid PHP callback. The followings are
* 事件处理程序必须是有效的PHP回调函数，方便内置方法call_user_fucn()调用
* some examples:
*
* ~~~
* function ($event) { ... } // anonymous function
* [$object, 'handleClick'] // $object->handleClick()
* ['Page', 'handleClick'] // Page::handleClick()
* 'handleClick' // global function handleClick()
* ~~~
*
* The event handler must be defined with the following signature,
*
* ~~~
* function ($event)
* ~~~
*
* where `$event` is an [[Event]] object which includes parameters associated with the event.
*
* @param string $name the event name 事件名
* @param callable $handler the event handler 事件处理函数
* @param mixed $data the data to be passed to the event handler when the event is triggered.
* 当事件被触发时，将传递给事件处理程序的数据。
* When the event handler is invoked, this data can be accessed via [[Event::data]].
* 当调用事件处理程序时，该数据可以通过 [[Event::data]] 访问
* @param boolean $append whether to append new event handler to the end of the existing
* handler list. If false, the new handler will be inserted at the beginning of the existing
* handler list.
* 是否将新事件处理程序附加到现有的处理程序列表的结尾。如果是错的，新的处理器将被插入在列表的开始的处理程序列表。
* @see off()
*/
public function on($name, $handler, $data = null, $append = true)
{
$this->ensureBehaviors();
//$append 判断是否添加到事件（event）的后面，确保_events中有该事件
if ($append || empty($this->_events[$name])) {
//将事件处理程序和参数添加到event数组末尾
$this->_events[$name][] = [$handler, $data];
} else {
//否则 添加到 event 的前面
array_unshift($this->_events[$name], [$handler, $data]);
}
} /**
* Detaches an existing event handler from this component.
* This method is the opposite of [[on()]].
* [[on()]]的反方法，用于删除事件处理程序
* @param string $name event name 事件名
* @param callable $handler the event handler to be removed. 事件处理程序
* If it is null, all handlers attached to the named event will be removed. 如果为空，清除所有的事件处理程序
* @return boolean if a handler is found and detached 是否发现并分离的处理程序
* @see on()
*/
public function off($name, $handler = null)
{
$this->ensureBehaviors();
// 相应的事件不存在，返回false
if (empty($this->_events[$name])) {
return false;
}
//没有handler，清除该事件的所有事件处理程序 并返回true
if ($handler === null) {
unset($this->_events[$name]);
return true;
} else {
$removed = false;//删除标记
foreach ($this->_events[$name] as $i => $event) {
if ($event[0] === $handler) {//遍历该事件 判断事件处理程序是否符合
unset($this->_events[$name][$i]);//删除该事件处理程序
$removed = true;
}
}
if ($removed) {
// 如果删除成功，就需要重新构建以下索引，重新赋值
$this->_events[$name] = array_values($this->_events[$name]);
}
return $removed;//成功标记
}
} /**
* Triggers an event. 触发事件
* This method represents the happening of an event. It invokes
* all attached handlers for the event including class-level handlers.
* @param string $name the event name 事件名
* @param Event $event the event parameter. If not set, a default [[Event]] object will be created.
* 事件参数. 如果未设置，默认的 [[Event]] 对象将被创建.
*/
public function trigger($name, Event $event = null)
{
//确保行为绑定
$this->ensureBehaviors();
if (!empty($this->_events[$name])) {
// 事件名不为空 构建Event对象，为传入到handler函数中做准备
if ($event === null) {
$event = new Event;
}
if ($event->sender === null) {
$event->sender = $this;
}
$event->handled = false;
$event->name = $name;
foreach ($this->_events[$name] as $handler) {
// 遍历事件 给事件的data属性赋值
$event->data = $handler[1];
// handler的函数中传入了一个Event对象
call_user_func($handler[0], $event);
// stop further handling if the event is handled
// 事件是否被处理，如果了处理事件即handled被设置为true时，停止进一步处理
if ($event->handled) {
return;
}
}
}
// invoke class-level attached handlers [[Event]] 的方法，触发类级别的事件处理程序
Event::trigger($this, $name, $event);
} /**
* Returns the named behavior object.获取行为类
* @param string $name the behavior name 行为名
* @return Behavior the behavior object, or null if the behavior does not exist 行为对象，如果行为不存在为null
*/
public function getBehavior($name)
{
//确保行为绑定
$this->ensureBehaviors();
//_behaviors中的行为类存在，返回行为类名，否则返回空
return isset($this->_behaviors[$name]) ? $this->_behaviors[$name] : null;
} /**
* Returns all behaviors attached to this component. 获取所有的行为类
* @return Behavior[] list of behaviors attached to this component
*/
public function getBehaviors()
{
$this->ensureBehaviors(); //确保行为绑定
return $this->_behaviors; //直接返回所有行为
} /**
* Attaches a behavior to this component.
* 内部使用的添加一个行为到该组件
* This method will create the behavior object based on the given
* configuration. After that, the behavior object will be attached to
* this component by calling the [[Behavior::attach()]] method.
* 通过提供的配置文件创建一个Behavior对象，通过调用 [[Behavior::attach()]] 方法添加行为到组件.
* @param string $name the name of the behavior. 行为名
* @param string|array|Behavior $behavior the behavior configuration. This can be one of the following:
* behavior配置
* - a [[Behavior]] object 一个[[Behavior]]类
* - a string specifying the behavior class 一个字符串形式的指定行为类
* - an object configuration array that will be passed to [[Yii::createObject()]] to create the behavior object.
* 一个配置文件数组，通过调用[[Yii::createObject()]] 创建一个行为对象.
* @return Behavior the behavior object 行为对象
* @see detachBehavior()
*/
public function attachBehavior($name, $behavior)
{
$this->ensureBehaviors();//确保行为绑定
return $this->attachBehaviorInternal($name, $behavior); //添加行为
} /**
* Attaches a list of behaviors to the component. 添加行为列表到组件
* Each behavior is indexed by its name and should be a [[Behavior]] object,
* a string specifying the behavior class, or an configuration array for creating the behavior.
* 行为类通过行为名索引，且必须是一个 [[Behavior]] 对象指定的行为类或者一个配置数组
* @param array $behaviors list of behaviors to be attached to the component 行为列表
* @see attachBehavior()
*/
public function attachBehaviors($behaviors)
{
$this->ensureBehaviors();//确保行为绑定
foreach ($behaviors as $name => $behavior) {
//添加行为列表
$this->attachBehaviorInternal($name, $behavior);
}
} /**
* Detaches a behavior from the component. 从组件解除行为
* The behavior's [[Behavior::detach()]] method will be invoked. 通过[[Behavior::detach()]]解除行为
* @param string $name the behavior's name. 行为名
* @return Behavior the detached behavior. Null if the behavior does not exist. 存在返回分离行为 不存在返回null
*/
public function detachBehavior($name)
{
$this->ensureBehaviors();//确保行为绑定
if (isset($this->_behaviors[$name])) {
//行为存在，解除行为
$behavior = $this->_behaviors[$name];
unset($this->_behaviors[$name]);
//返回分离行为
$behavior->detach();
return $behavior;
} else {
return null;
}
} /**
* Detaches all behaviors from the component. 解除所有行为
*/
public function detachBehaviors()
{
$this->ensureBehaviors();//确保行为绑定
foreach ($this->_behaviors as $name => $behavior) {
//遍历解除行为
$this->detachBehavior($name);
}
} /**
* Makes sure that the behaviors declared in [[behaviors()]] are attached to this component.
* 确保声明的行为都被添加到组件
*/
public function ensureBehaviors()
{
if ($this->_behaviors === null) {
$this->_behaviors = [];
foreach ($this->behaviors() as $name => $behavior) {
//遍历$this->behaviors()中的behaviors，并添加到$this->_behaviors数组中
$this->attachBehaviorInternal($name, $behavior);
}
}
} /**
* Attaches a behavior to this component. 内部使用的为该对象添加behavior的方法
* @param string|integer $name the name of the behavior. If this is an integer, it means the behavior
* is an anonymous one. Otherwise, the behavior is a named one and any existing behavior with the same name
* will be detached first. 行为名. 如果是整数，说明该行为是匿名的
* @param string|array|Behavior $behavior the behavior to be attached 添加的行为 string|array|Behavior
* @return Behavior the attached behavior.
*/
private function attachBehaviorInternal($name, $behavior)
{
if (!($behavior instanceof Behavior)) {
// $behavior不是Behavior对象，认为是配置，则创建一个$behavior对象
$behavior = Yii::createObject($behavior);
}
if (is_int($name)) {//行为是整数，绑定到组件
$behavior->attach($this);
$this->_behaviors[] = $behavior;
} else {
if (isset($this->_behaviors[$name])) {
// 如果有同名的行为存在就先解绑掉
$this->_behaviors[$name]->detach();
}
$behavior->attach($this);//重新绑定行为到组件
$this->_behaviors[$name] = $behavior;
}
return $behavior;
}