Component类

原文地址: http://www.cnblogs.com/dragon16/p/5521199.html

组件（component），是Yii框架的基类，实现了属性、事件、行为三类功能，如果需要事件和行为的功能，需要继承该类。

<?php/** * @link http://www.yiiframework.com/ * @copyright Copyright (c) 2008 Yii Software LLC * @license http://www.yiiframework.com/license/ */namespace yii\base;//命名空间use Yii;//加载Yii相关类/** * Component is the base class that implements the *property*, *event* and *behavior* features. * 组件是实现属性、事件、行为的基类 * Component provides the *event* and *behavior* features, in addition to the *property* feature which is implemented in * its parent class [[Object]]. * 组件提供事件和行为，继承他父类Object的特点 * Event is a way to "inject" custom code into existing code at certain places. For example, a comment object can trigger * an "add" event when the user adds a comment. We can write custom code and attach it to this event so that when the event * is triggered (i.e. comment will be added), our custom code will be executed. *  * An event is identified by a name that should be unique within the class it is defined at. Event names are *case-sensitive*. * 事件是一种在特定的地方“注入”自定义代码到现有的代码。例如， * 当一个用户添加评论事件时，注释的对象可以触发。我们可以编写自定义代码，并将其附加到此事件，这样当事件被触发（即评论将被添加）， * * 我们的自定义代码会被执行， * One or multiple PHP callbacks, called *event handlers*, can be attached to an event. You can call [[trigger()]] to * raise an event. When an event is raised, the event handlers will be invoked automatically in the order they were * attached. * * To attach an event handler to an event, call [[on()]]: * 一个或多个php回调，称为为‘事件处理’。要触发一个事件处理，可以用on();举个例子。 * ~~~ * $post->on('update', function ($event) { *     // send email notification * }); * ~~~ * * In the above, an anonymous function is attached to the "update" event of the post. You may attach * the following types of event handlers: *  一个匿名函数被连接到'update'事件后。可以用以下类型的程序做处理： * - anonymous function: `function ($event) { ... }`    匿名函数 * - object method: `[$object, 'handleAdd']`            对象方法 * - static class method: `['Page', 'handleAdd']`       静态类方法 * - global function: `'handleAdd'`                     全局函数 * * The signature of an event handler should be like the following: * 一个事件处理程序的签名应该是如下： * ~~~ * function foo($event) * ~~~ * * where `$event` is an [[Event]] object which includes parameters associated with the event. * $event是一个[[Event]]对象 包括与事件相关联的参数。 * You can also attach a handler to an event when configuring a component with a configuration array. * The syntax is like the following: * 还可以将处理程序附加到配置数组中配置组件的事件。语法如下： * ~~~ * [ *     'on add' => function ($event) { ... } * ] * ~~~ * * where `on add` stands for attaching an event to the `add` event. * `on add` 代表添加事件 * Sometimes, you may want to associate extra data with an event handler when you attach it to an event * and then access it when the handler is invoked. You may do so by * 有时，当你将它附加到一个事件时，你可能会把额外的数据与事件处理程序关联起来 * 然后在调用处理程序时访问它。 * ~~~ * $post->on('update', function ($event) { *     // the data can be accessed via $event->data * }, $data); * ~~~ * * A behavior is an instance of [[Behavior]] or its child class. A component can be attached with one or multiple * behaviors. When a behavior is attached to a component, its public properties and methods can be accessed via the * component directly, as if the component owns those properties and methods. * 行为是行为的一个实例或它的子类。一个组件可以连接一个或多个 * 行为。当一个行为被连接到一个组件，它的公共属性和方法可以通过访问 * 组件的直接组件，因为组件拥有这些属性和方法。 * To attach a behavior to a component, declare it in [[behaviors()]], or explicitly call [[attachBehavior]]. Behaviors * declared in [[behaviors()]] are automatically attached to the corresponding component. * * One can also attach a behavior to a component when configuring it with a configuration array. The syntax is like the * following: * * ~~~ * [ *     'as tree' => [ *         'class' => 'Tree', *     ], * ] * ~~~ * * where `as tree` stands for attaching a behavior named `tree`, and the array will be passed to [[\Yii::createObject()]] * to create the behavior object. * * @property Behavior[] $behaviors List of behaviors attached to this component. This property is read-only. * * @author Qiang Xue <[e-mail]> * @since 2.0 *///该类继承了Object类class Component extends Object{    /**     * @var array the attached event handlers (event name => handlers)     * 存储对象的事件处理程序，是一个数组     */    private $_events = [];    /**     * @var Behavior[]|null the attached behaviors (behavior name => behavior). This is `null` when not initialized.     * 赋值给对象的行为，默认值为null     */    private $_behaviors;    /**     * Returns the value of a component property.     * 得到属性值     * This method will check in the following order and act accordingly:     *     *  - a property defined by a getter: return the getter result     *  - a property of a behavior: return the behavior property value     *     * Do not call this method directly as it is a PHP magic method that     * 重写 Object 中的 getter 方法     * 返回一个组件的属性值。     * 这个方法将检查以下顺序并采取相应的行动：     *     * - 通过一个getter定义的属性：返回getter的结果     * - 一个行为的属性：返回的行为属性值     *     * 不要直接调用此方法，因为它是一个PHP魔术方法     * will be implicitly called when executing `$value = $component->property;`.     * @param string $name the property name    参数属性名     * @return mixed the property value or the value of a behavior's property 返回混合属性的值或行为属性的值     * @throws UnknownPropertyException if the property is not defined  如果没有定义，抛出信息     * @throws InvalidCallException if the property is write-only.  该属性是只写的     * @see __set()     */    public function __get($name)    {        $getter = 'get' . $name;    //定义$getter        if (method_exists($this, $getter)) {            // read property, e.g. getName()            //方法存在且被调用时，读取属性            return $this->$getter();        } else {            // behavior property            $this->ensureBehaviors(); //确保行为已经绑定            foreach ($this->_behaviors as $behavior) {                if ($behavior->canGetProperty($name)) {                    /**                     * 判断检查对象或类是否能够获取 $name 属性，                     * 如果 behavior 中含有该属性，就返回 behavior 中的这个属性                     * 第二个参数为 true（默认是true），则不局限于是否有 getter                     */                    return $behavior->$name;                }            }        }        if (method_exists($this, 'set' . $name)) {//方法存在且调用，返回true            throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);            //抛出只读属性        } else {            throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);            //错误扔出异常        }    }    /**     * Sets the value of a component property.  设置属性值     * This method will check in the following order and act accordingly:检查并执行     *     *  - a property defined by a setter: set the property value     *  - an event in the format of "on xyz": attach the handler to the event "xyz"     *  - a behavior in the format of "as xyz": attach the behavior named as "xyz"     *  - a property of a behavior: set the behavior property value     * 重写 Object 中的 setter 方法     * 由一个setter定义的属性:设置属性值。     * 如果 $name 是 'on xyz'，就会将 xyz 事件添加到该对象中     * 如果 $name 是 'as xyz'，就会将 xyz 行为添加到该对象中     * 添加对 behaviors 的处理，循环 behaviors，如果其中有相应的属性，就设置它     * Do not call this method directly as it is a PHP magic method that     * will be implicitly called when executing `$component->property = $value;`.     * @param string $name the property name or the event name 属性名或者事件名     * @param mixed $value the property value       属性值     * @throws UnknownPropertyException if the property is not defined  未定义扔出错误     * @throws InvalidCallException if the property is read-only.   抛出信息 只读     * @see __get()     */    public function __set($name, $value)    {        $setter = 'set' . $name;//在属性名前面加set构建setter方法        if (method_exists($this, $setter)) {            // set property            //如果setter方法存在返回true,没有返回false.    调用该方法设置属性值            $this->$setter($value);            return;        } elseif (strncmp($name, 'on ', 3) === 0) {//比较$name和'on '前3个字符，如果$name以on+空格开始，就添加事件            // on event: attach event handler            $this->on(trim(substr($name, 3)), $value);//执行on 方法，用来添加附加事件。            return;        } elseif (strncmp($name, 'as ', 3) === 0) {//如果$name以as+空格开始，就添加行为            // as behavior: attach behavior            $name = trim(substr($name, 3));//截取as后面的字符，用attachBehavior来添加附加行为。            //$value这个对象是Behavior类的一个实例，取$value为参数，否则静态调用Yii方法创造一个新的对象。            $this->attachBehavior($name, $value instanceof Behavior ? $value : Yii::createObject($value));            return;        } else {            // behavior property            $this->ensureBehaviors();//确保行为已经绑定            foreach ($this->_behaviors as $behavior) {                if ($behavior->canSetProperty($name)) {//遍历行为，如果行为中有可以设置的属性$name                    $behavior->$name = $value;//给该行为类中的属性设置属性值                        return;                }            }        }        if (method_exists($this, 'get' . $name)) {//如果'get'.$name这个方法存在，就抛出只读信息.            throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);        } else {            //如果不属于这个类，就抛出异常.            throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);        }    }    /**     * Checks if a property value is null.     * 属性是否为空     * This method will check in the following order and act accordingly:     *     *  - a property defined by a setter: return whether the property value is null     *  - a property of a behavior: return whether the property value is null     *  重写 Object 中的 isset 方法 通过一个setter定义的属性：返回属性是否设置     * 行为的属性:返回属性值是否设置     * Do not call this method directly as it is a PHP magic method that     * will be implicitly called when executing `isset($component->property)`.     * @param string $name the property name or the event name  属性名或事件名     * @return boolean whether the named property is null   　属性值是否被设置 返回true/boolean值。     */    public function __isset($name)    {        $getter = 'get' . $name;        if (method_exists($this, $getter)) {             // 判断是否有getter方法，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 {            // behavior property            $this->ensureBehaviors();//确定行为已经绑定            foreach ($this->_behaviors as $behavior) {//遍历行为                if ($behavior->canGetProperty($name)) {                    // 如果 behavior 中有 $name 属性，且不为 null，该属性存在 返回 true                    return $behavior->$name !== null;                }            }        }        return false;    }    /**     * Sets a component property to be null.     * 设置属性为null，即删除属性     * This method will check in the following order and act accordingly:     *     *  - a property defined by a setter: set the property value to be null     *  - a property of a behavior: set the property value to be null     * 重写 Object 中的 unset 方法，     * 通过setter定义的属性：设置该属性值为空      * 属性的行为：将属性值设为空     * Do not call this method directly as it is a PHP magic method that     * will be implicitly called when executing `unset($component->property)`.     * @param string $name the property name    属性名     * @throws InvalidCallException if the property is read only.   该属性只读，抛出异常     */    public function __unset($name)    {        $setter = 'set' . $name;        if (method_exists($this, $setter)) {            //如果$setter方法存在，通过setter方法把它设置为空            $this->$setter(null);            return;        } else {            // behavior property            $this->ensureBehaviors();            foreach ($this->_behaviors as $behavior) {//遍历行为                if ($behavior->canSetProperty($name)) {//存在$name值，设为空                    $behavior->$name = null;                    return;                }            }        }        //抛出异常        throw new InvalidCallException('Unsetting an unknown or read-only property: ' . get_class($this) . '::' . $name);    }    /**     * Calls the named method which is not a class method.     *      * This method will check if any attached behavior has     * the named method and will execute it if available.     * 调用方法名 重写 Object 中的 call 方法，添加对行为的处理，循环 behaviors，     * 如果其中有相应方法，就执行该 behavior 的方法     * 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 $params method parameters     * @return mixed the method return value     * @throws UnknownMethodException when calling unknown method     */    public function __call($name, $params)    {        $this->ensureBehaviors();        foreach ($this->_behaviors as $object) {            if ($object->hasMethod($name)) {                //行为中存在名为 $name 的方法，就执行它                //call_user_func_array 调用回调函数，并把一个数组参数作为回调函数的参数                return call_user_func_array([$object, $name], $params);            }        }        //抛出异常        throw new UnknownMethodException('Calling unknown method: ' . get_class($this) . "::$name()");    }    /**     * This method is called after the object is created by cloning an existing one.     * It removes all behaviors because they are attached to the old object.     * 通过克隆现有创建的对象后，此方法会被调用。　　 * 他将会消除所有的行为。所有的引用属性 仍然会是一个指向原来的变量的引用     */    public function __clone()    {        // 对象复制时，将它的 _events 设置为空数组，将 _behaviors 设置为 null        $this->_events = [];        $this->_behaviors = null;    }

/**     * 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;    }