<?php
namespace yii\base;
class Component
{
private $_e;
private $_b;
/**
* Returns a property value, an event handler list or a behavior based on its name.
* Do not call this method. This is a PHP magic method that we override
* to allow using the following syntax to read a property or obtain event handlers:
* <pre>
* $value=$component->propertyName;
* $handlers=$component->eventName;
* </pre>
* @param string $name the property name or event name
* @return mixed the property value, event handlers attached to the event, or the named behavior (since version 1.0.2)
* @throws CException if the property or event is not defined
* @see __set
*/
public function __get($name)
{
$getter = 'get' . $name;
if (method_exists($this, $getter)) { // read property, e.g. getName()
return $this->$getter();
}
elseif (method_exists($this, $name) && strncasecmp($name, 'on', 2) === 0) { // event, e.g. onClick()
$name = strtolower($name);
if (!isset($this->_e[$name])) {
$this->_e[$name] = new \yii\collections\Vector;
}
return $this->_e[$name];
}
elseif (isset($this->_b[$name])) { // behavior
return $this->_b[$name];
}
elseif (is_array($this->_b)) { // a behavior property
foreach ($this->_b as $object) {
if ($object->getEnabled() && $object->canGetProperty($name)) {
return $object->$name;
}
}
}
throw new Exception('Getting unknown property: ' . get_class($this) . '.' $name);
}
/**
* Sets value of a component property.
* Do not call this method. This is a PHP magic method that we override
* to allow using the following syntax to set a property or attach an event handler
* <pre>
* $this->propertyName=$value;
* $this->eventName=$callback;
* </pre>
* @param string $name the property name or the event name
* @param mixed $value the property value or callback
* @throws CException if the property/event is not defined or the property is read only.
* @see __get
*/
public function __set($name, $value)
{
$setter = 'set' . $name;
if (method_exists($this, $setter)) {
return $this->$setter($value);
}
elseif (method_exists($this, $name) && strncasecmp($name, 'on', 2) === 0) {
$name = strtolower($name);
if (!isset($this->_e[$name])) {
$this->_e[$name] = new \yii\collections\Vector;
}
return $this->_e[$name]->add($value);
}
elseif (is_array($this->_b)) {
foreach ($this->_b as $object) {
if ($object->getEnabled() && $object->canSetProperty($name)) {
return $object->$name = $value;
}
}
}
if (method_exists($this, 'get' . $name)) {
throw new Exception('Setting read-only property: ' . get_class($this) . '.' $name);
}
else {
throw new Exception('Setting unknown property: ' . get_class($this) . '.' $name);
}
}
/**
* Checks if a property value is null.
* Do not call this method. This is a PHP magic method that we override
* to allow using isset() to detect if a component property is set or not.
* @param string $name the property name or the event name
* @since 1.0.1
*/
public function __isset($name)
{
$getter = 'get' . $name;
if (method_exists($this, $getter)) { // property is not null
return $this->$getter() !== null;
}
elseif (method_exists($this, $name) && strncasecmp($name, 'on', 2) === 0) { // has event handler
$name = strtolower($name);
return isset($this->_e[$name]) && $this->_e[$name]->getCount();
}
elseif (isset($this->_b[$name])) { // has behavior
return true;
}
elseif (is_array($this->_b)) {
foreach ($this->_b as $object) {
if ($object->getEnabled() && $object->canGetProperty($name)) {
return $object->$name !== null;
}
}
}
return false;
}
/**
* Sets a component property to be null.
* Do not call this method. This is a PHP magic method that we override
* to allow using unset() to set a component property to be null.
* @param string $name the property name or the event name
* @throws CException if the property is read only.
* @since 1.0.1
*/
public function __unset($name)
{
$setter = 'set' . $name;
if (method_exists($this, $setter)) {
$this->$setter(null);
}
elseif (method_exists($this, $name) && strncasecmp($name, 'on', 2) === 0) {
unset($this->_e[strtolower($name)]);
}
elseif (isset($this->_b[$name])) {
$this->detachBehavior($name);
}
elseif (is_array($this->_b)) {
foreach ($this->_b as $object)
{
if ($object->getEnabled() && $object->canSetProperty($name)) {
return $object->$name = null;
}
}
}
elseif (method_exists($this, 'get' . $name))
throw new Exception('Unsetting read-only property: ' . get_class($this) . '.' $name);
}
/**
* Calls the named method which is not a class method.
* Do not call this method. This is a PHP magic method that we override
* to implement the behavior feature.
* @param string $name the method name
* @param array $parameters method parameters
* @return mixed the method return value
* @since 1.0.2
*/
public function __call($name, $parameters)
{
if ($this->_b !== null)
{
foreach ($this->_b as $object)
{
if ($object->getEnabled() && method_exists($object, $name)) {
return call_user_func_array(array($object, $name), $parameters);
}
}
}
if ($this->canGetProperty($name)) {
$func = $this->$name;
if ($func instanceof \Closure) {
return call_user_func_array($func, $parameters);
}
}
throw new Exception('Unknown method: ' . get_class($this) . '::' $name . '()');
}
/**
* Returns the named behavior object.
* The name 'asa' stands for 'as a'.
* @param string $behavior the behavior name
* @return IBehavior the behavior object, or null if the behavior does not exist
* @since 1.0.2
*/
public function asa($behavior)
{
return isset($this->_b[$behavior]) ? $this->_b[$behavior] : null;
}
/**
* Attaches a list of behaviors to the component.
* Each behavior is indexed by its name and should be an instance of
* {@link IBehavior}, a string specifying the behavior class, or an
* array of the following structure:
* <pre>
* array(
* 'class'=>'path.to.BehaviorClass',
* 'property1'=>'value1',
* 'property2'=>'value2',
* )
* </pre>
* @param array $behaviors list of behaviors to be attached to the component
* @since 1.0.2
*/
public function attachBehaviors($behaviors)
{
foreach ($behaviors as $name => $behavior)
$this->attachBehavior($name, $behavior);
}
/**
* Detaches all behaviors from the component.
* @since 1.0.2
*/
public function detachBehaviors()
{
if ($this->_b !== null)
{
foreach ($this->_b as $name => $behavior)
$this->detachBehavior($name);
$this->_b = null;
}
}
/**
* Attaches a behavior to this component.
* This method will create the behavior object based on the given
* configuration. After that, the behavior object will be initialized
* by calling its {@link IBehavior::attach} method.
* @param string $name the behavior's name. It should uniquely identify this behavior.
* @param mixed $behavior the behavior configuration. This is passed as the first
* parameter to {@link YiiBase::createComponent} to create the behavior object.
* @return IBehavior the behavior object
* @since 1.0.2
*/
public function attachBehavior($name, $behavior)
{
if (!($behavior instanceof IBehavior))
$behavior = Yii::createComponent($behavior);
$behavior->setEnabled(true);
$behavior->attach($this);
return $this->_b[$name] = $behavior;
}
/**
* Detaches a behavior from the component.
* The behavior's {@link IBehavior::detach} method will be invoked.
* @param string $name the behavior's name. It uniquely identifies the behavior.
* @return IBehavior the detached behavior. Null if the behavior does not exist.
* @since 1.0.2
*/
public function detachBehavior($name)
{
if (isset($this->_b[$name]))
{
$this->_b[$name]->detach($this);
$behavior = $this->_b[$name];
unset($this->_b[$name]);
return $behavior;
}
}
/**
* Enables all behaviors attached to this component.
* @since 1.0.2
*/
public function enableBehaviors()
{
if ($this->_b !== null)
{
foreach ($this->_b as $behavior)
$behavior->setEnabled(true);
}
}
/**
* Disables all behaviors attached to this component.
* @since 1.0.2
*/
public function disableBehaviors()
{
if ($this->_b !== null)
{
foreach ($this->_b as $behavior)
$behavior->setEnabled(false);
}
}
/**
* Enables an attached behavior.
* A behavior is only effective when it is enabled.
* A behavior is enabled when first attached.
* @param string $name the behavior's name. It uniquely identifies the behavior.
* @since 1.0.2
*/
public function enableBehavior($name)
{
if (isset($this->_b[$name]))
$this->_b[$name]->setEnabled(true);
}
/**
* Disables an attached behavior.
* A behavior is only effective when it is enabled.
* @param string $name the behavior's name. It uniquely identifies the behavior.
* @since 1.0.2
*/
public function disableBehavior($name)
{
if (isset($this->_b[$name]))
$this->_b[$name]->setEnabled(false);
}
/**
* Determines whether a property is defined.
* A property is defined if there is a getter or setter method
* defined in the class. Note, property names are case-insensitive.
* @param string $name the property name
* @param boolean $checkVar whether to check class properties. If false, only properties declared by getters will be checked.
* @return boolean whether the property is defined
* @see canGetProperty
* @see canSetProperty
*/
public function hasProperty($name, $checkVar = true)
{
return method_exists($this, 'get' . $name) || method_exists($this, 'set' . $name) || property_exists($this, $name);
}
/**
* Determines whether a property can be read.
* A property can be read if the class has a getter method
* for the property name. Note, property name is case-insensitive.
* @param string $name the property name
* @param boolean $checkVar whether to check class properties. If false, only properties declared by getters will be checked.
* @return boolean whether the property can be read
* @see canSetProperty
*/
public function canGetProperty($name, $checkVar = true)
{
return method_exists($this, 'get' . $name) || $checkVar && property_exists($this, $name);
}
/**
* Determines whether a property can be set.
* A property can be written if the class has a setter method
* for the property name. Note, property name is case-insensitive.
* @param string $name the property name
* @param boolean $checkVar whether to check class properties. If false, only properties declared by setters will be checked.
* @return boolean whether the property can be written
* @see canGetProperty
*/
public function canSetProperty($name, $checkVar = true)
{
return method_exists($this, 'set' . $name) || $checkVar && property_exists($this, $name);
}
/**
* Determines whether an event is defined.
* An event is defined if the class has a method named like 'onXXX'.
* Note, event name is case-insensitive.
* @param string $name the event name
* @return boolean whether an event is defined
*/
public function hasEvent($name)
{
return !strncasecmp($name, 'on', 2) && method_exists($this, $name);
}
/**
* Checks whether the named event has attached handlers.
* @param string $name the event name
* @return boolean whether an event has been attached one or several handlers
*/
public function hasEventHandler($name)
{
$name = strtolower($name);
return isset($this->_e[$name]) && $this->_e[$name]->getCount() > 0;
}
/**
* Returns the list of attached event handlers for an event.
* @param string $name the event name
* @return CList list of attached event handlers for the event
* @throws CException if the event is not defined
*/
public function getEventHandlers($name)
{
if ($this->hasEvent($name))
{
$name = strtolower($name);
if (!isset($this->_e[$name]))
$this->_e[$name] = new CList;
return $this->_e[$name];
}
else
throw new CException(Yii::t('yii', 'Event "{class}.{event}" is not defined.',
array('{class}' => get_class($this), '{event}' => $name)));
}
/**
* Attaches an event handler to an event.
*
* An event handler must be a valid PHP callback, i.e., a string referring to
* a global function name, or an array containing two elements with
* the first element being an object and the second element a method name
* of the object.
*
* An event handler must be defined with the following signature,
* <pre>
* function handlerName($event) {}
* </pre>
* where $event includes parameters associated with the event.
*
* This is a convenient method of attaching a handler to an event.
* It is equivalent to the following code:
* <pre>
* $component->getEventHandlers($eventName)->add($eventHandler);
* </pre>
*
* Using {@link getEventHandlers}, one can also specify the excution order
* of multiple handlers attaching to the same event. For example:
* <pre>
* $component->getEventHandlers($eventName)->insertAt(0,$eventHandler);
* </pre>
* makes the handler to be invoked first.
*
* @param string $name the event name
* @param callback $handler the event handler
* @throws CException if the event is not defined
* @see detachEventHandler
*/
public function attachEventHandler($name, $handler)
{
$this->getEventHandlers($name)->add($handler);
}
/**
* Detaches an existing event handler.
* This method is the opposite of {@link attachEventHandler}.
* @param string $name event name
* @param callback $handler the event handler to be removed
* @return boolean if the detachment process is successful
* @see attachEventHandler
*/
public function detachEventHandler($name, $handler)
{
if ($this->hasEventHandler($name))
return $this->getEventHandlers($name)->remove($handler) !== false;
else
return false;
}
/**
* Raises an event.
* This method represents the happening of an event. It invokes
* all attached handlers for the event.
* @param string $name the event name
* @param CEvent $event the event parameter
* @throws CException if the event is undefined or an event handler is invalid.
*/
public function raiseEvent($name, $event)
{
$name = strtolower($name);
if (isset($this->_e[$name]))
{
foreach ($this->_e[$name] as $handler)
{
if (is_string($handler))
call_user_func($handler, $event);
elseif (is_callable($handler, true))
{
if (is_array($handler))
{
// an array: 0 - object, 1 - method name
list($object, $method) = $handler;
if (is_string($object)) // static method call
call_user_func($handler, $event);
elseif (method_exists($object, $method))
$object->$method($event);
else
throw new CException(Yii::t('yii', 'Event "{class}.{event}" is attached with an invalid handler "{handler}".',
array('{class}' => get_class($this), '{event}' => $name, '{handler}' => $handler[1])));
}
else // PHP 5.3: anonymous function
call_user_func($handler, $event);
}
else
throw new CException(Yii::t('yii', 'Event "{class}.{event}" is attached with an invalid handler "{handler}".',
array('{class}' => get_class($this), '{event}' => $name, '{handler}' => gettype($handler))));
// stop further handling if param.handled is set true
if (($event instanceof CEvent) && $event->handled)
return;
}
}
elseif (YII_DEBUG && !$this->hasEvent($name))
throw new CException(Yii::t('yii', 'Event "{class}.{event}" is not defined.',
array('{class}' => get_class($this), '{event}' => $name)));
}
/**
* Evaluates a PHP expression or callback under the context of this component.
*
* Valid PHP callback can be class method name in the form of
* array(ClassName/Object, MethodName), or anonymous function (only available in PHP 5.3.0 or above).
*
* If a PHP callback is used, the corresponding function/method signature should be
* <pre>
* function foo($param1, $param2, ..., $component) { ... }
* </pre>
* where the array elements in the second parameter to this method will be passed
* to the callback as $param1, $param2, ...; and the last parameter will be the component itself.
*
* If a PHP expression is used, the second parameter will be "extracted" into PHP variables
* that can be directly accessed in the expression. See {@link http://us.php.net/manual/en/function.extract.php PHP extract}
* for more details. In the expression, the component object can be accessed using $this.
*
* @param mixed $_expression_ a PHP expression or PHP callback to be evaluated.
* @param array $_data_ additional parameters to be passed to the above expression/callback.
* @return mixed the expression result
* @since 1.1.0
*/
public function evaluateExpression($_expression_, $_data_ = array())
{
if (is_string($_expression_))
{
extract($_data_);
return eval('return ' . $_expression_ . ';');
}
else
{
$_data_[] = $this;
return call_user_func_array($_expression_, $_data_);
}
}
}