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Class yii\i18n\GettextMessageSource

Inheritanceyii\i18n\GettextMessageSource » yii\i18n\MessageSource » yii\base\Component » yii\base\BaseObject
Implementsyii\base\Configurable
Available since version2.0
Source Code https://github.com/yiisoft/yii2/blob/master/framework/i18n/GettextMessageSource.php

GettextMessageSource represents a message source that is based on GNU Gettext.

Each GettextMessageSource instance represents the message translations for a single domain. And each message category represents a message context in Gettext. Translated messages are stored as either a MO or PO file, depending on the $useMoFile property value.

All translations are saved under the $basePath directory.

Translations in one language are kept as MO or PO files under an individual subdirectory whose name is the language ID. The file name is specified via $catalog property, which defaults to 'messages'.

Public Properties

Hide inherited properties

Property Type Description Defined By
$basePath string Base directory of messages files yii\i18n\GettextMessageSource
$behaviors yii\base\Behavior[] List of behaviors attached to this component. yii\base\Component
$catalog string Sub-directory of messages files yii\i18n\GettextMessageSource
$forceTranslation boolean Whether to force message translation when the source and target languages are the same. yii\i18n\MessageSource
$sourceLanguage string|null The language that the original messages are in. yii\i18n\MessageSource
$useBigEndian boolean Whether to use big-endian when reading and writing an integer yii\i18n\GettextMessageSource
$useMoFile boolean Whether to use generated MO files yii\i18n\GettextMessageSource

Public Methods

Hide inherited methods

Method Description Defined By
__call() Calls the named method which is not a class method. yii\base\Component
__clone() This method is called after the object is created by cloning an existing one. yii\base\Component
__construct() Constructor. yii\base\BaseObject
__get() Returns the value of a component property. yii\base\Component
__isset() Checks if a property is set, i.e. defined and not null. yii\base\Component
__set() Sets the value of a component property. yii\base\Component
__unset() Sets a component property to be null. yii\base\Component
attachBehavior() Attaches a behavior to this component. yii\base\Component
attachBehaviors() Attaches a list of behaviors to the component. yii\base\Component
behaviors() Returns a list of behaviors that this component should behave as. yii\base\Component
canGetProperty() Returns a value indicating whether a property can be read. yii\base\Component
canSetProperty() Returns a value indicating whether a property can be set. yii\base\Component
className() Returns the fully qualified name of this class. yii\base\BaseObject
detachBehavior() Detaches a behavior from the component. yii\base\Component
detachBehaviors() Detaches all behaviors from the component. yii\base\Component
ensureBehaviors() Makes sure that the behaviors declared in behaviors() are attached to this component. yii\base\Component
getBehavior() Returns the named behavior object. yii\base\Component
getBehaviors() Returns all behaviors attached to this component. yii\base\Component
hasEventHandlers() Returns a value indicating whether there is any handler attached to the named event. yii\base\Component
hasMethod() Returns a value indicating whether a method is defined. yii\base\Component
hasProperty() Returns a value indicating whether a property is defined for this component. yii\base\Component
init() Initializes this component. yii\i18n\MessageSource
off() Detaches an existing event handler from this component. yii\base\Component
on() Attaches an event handler to an event. yii\base\Component
translate() Translates a message to the specified language. yii\i18n\MessageSource
trigger() Triggers an event. yii\base\Component

Protected Methods

Hide inherited methods

Method Description Defined By
getMessageFilePath() Returns message file path for the specified language and category. yii\i18n\GettextMessageSource
loadFallbackMessages() The method is normally called by loadMessages() to load the fallback messages for the language. yii\i18n\GettextMessageSource
loadMessages() Loads the message translation for the specified $language and $category. yii\i18n\GettextMessageSource
loadMessagesFromFile() Loads the message translation for the specified language and category or returns null if file doesn't exist. yii\i18n\GettextMessageSource
translateMessage() Translates the specified message. yii\i18n\MessageSource

Events

Hide inherited events

Event Type Description Defined By
EVENT_MISSING_TRANSLATION yii\i18n\MissingTranslationEvent An event that is triggered when a message translation is not found. yii\i18n\MessageSource

Constants

Hide inherited constants

Constant Value Description Defined By
MO_FILE_EXT '.mo' yii\i18n\GettextMessageSource
PO_FILE_EXT '.po' yii\i18n\GettextMessageSource

Property Details

Hide inherited properties

$basePath public property

Base directory of messages files

public string $basePath '@app/messages'
$catalog public property

Sub-directory of messages files

public string $catalog 'messages'
$useBigEndian public property

Whether to use big-endian when reading and writing an integer

public boolean $useBigEndian false
$useMoFile public property

Whether to use generated MO files

public boolean $useMoFile true

Method Details

Hide inherited methods

__call() public method

Defined in: yii\base\Component::__call()

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.

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.

public mixed __call ( $name, $params )
$name string

The method name

$params array

Method parameters

return mixed

The method return value

throws yii\base\UnknownMethodException

when calling unknown method

                public function __call($name, $params)
{
    $this->ensureBehaviors();
    foreach ($this->_behaviors as $object) {
        if ($object->hasMethod($name)) {
            return call_user_func_array([$object, $name], $params);
        }
    }
    throw new UnknownMethodException('Calling unknown method: ' . get_class($this) . "::$name()");
}

            
__clone() public method

Defined in: yii\base\Component::__clone()

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.

public void __clone ( )

                public function __clone()
{
    $this->_events = [];
    $this->_eventWildcards = [];
    $this->_behaviors = null;
}

            
__construct() public method

Defined in: yii\base\BaseObject::__construct()

Constructor.

The default implementation does two things:

  • Initializes the object with the given configuration $config.
  • 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.
public void __construct ( $config = [] )
$config array

Name-value pairs that will be used to initialize the object properties

                public function __construct($config = [])
{
    if (!empty($config)) {
        Yii::configure($this, $config);
    }
    $this->init();
}

            
__get() public method

Defined in: yii\base\Component::__get()

Returns the value of a component property.

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 will be implicitly called when executing $value = $component->property;.

See also __set().

public mixed __get ( $name )
$name string

The property name

return mixed

The property value or the value of a behavior's property

throws yii\base\UnknownPropertyException

if the property is not defined

throws yii\base\InvalidCallException

if the property is write-only.

                public function __get($name)
{
    $getter = 'get' . $name;
    if (method_exists($this, $getter)) {
        // read property, e.g. getName()
        return $this->$getter();
    }
    // behavior property
    $this->ensureBehaviors();
    foreach ($this->_behaviors as $behavior) {
        if ($behavior->canGetProperty($name)) {
            return $behavior->$name;
        }
    }
    if (method_exists($this, 'set' . $name)) {
        throw new InvalidCallException('Getting write-only property: ' . get_class($this) . '::' . $name);
    }
    throw new UnknownPropertyException('Getting unknown property: ' . get_class($this) . '::' . $name);
}

            
__isset() public method

Defined in: yii\base\Component::__isset()

Checks if a property is set, i.e. defined and not null.

This method will check in the following order and act accordingly:

  • a property defined by a setter: return whether the property is set
  • a property of a behavior: return whether the property is set
  • return false for non existing properties

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing isset($component->property).

See also https://www.php.net/manual/en/function.isset.php.

public boolean __isset ( $name )
$name string

The property name or the event name

return boolean

Whether the named property is set

                public function __isset($name)
{
    $getter = 'get' . $name;
    if (method_exists($this, $getter)) {
        return $this->$getter() !== null;
    }
    // behavior property
    $this->ensureBehaviors();
    foreach ($this->_behaviors as $behavior) {
        if ($behavior->canGetProperty($name)) {
            return $behavior->$name !== null;
        }
    }
    return false;
}

            
__set() public method

Defined in: yii\base\Component::__set()

Sets the value of a component property.

This method will check in the following order and act accordingly:

  • 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

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing $component->property = $value;.

See also __get().

public void __set ( $name, $value )
$name string

The property name or the event name

$value mixed

The property value

throws yii\base\UnknownPropertyException

if the property is not defined

throws yii\base\InvalidCallException

if the property is read-only.

                public function __set($name, $value)
{
    $setter = 'set' . $name;
    if (method_exists($this, $setter)) {
        // set property
        $this->$setter($value);
        return;
    } elseif (strncmp($name, 'on ', 3) === 0) {
        // on event: attach event handler
        $this->on(trim(substr($name, 3)), $value);
        return;
    } elseif (strncmp($name, 'as ', 3) === 0) {
        // as behavior: attach behavior
        $name = trim(substr($name, 3));
        $this->attachBehavior($name, $value instanceof Behavior ? $value : Yii::createObject($value));
        return;
    }
    // behavior property
    $this->ensureBehaviors();
    foreach ($this->_behaviors as $behavior) {
        if ($behavior->canSetProperty($name)) {
            $behavior->$name = $value;
            return;
        }
    }
    if (method_exists($this, 'get' . $name)) {
        throw new InvalidCallException('Setting read-only property: ' . get_class($this) . '::' . $name);
    }
    throw new UnknownPropertyException('Setting unknown property: ' . get_class($this) . '::' . $name);
}

            
__unset() public method

Defined in: yii\base\Component::__unset()

Sets a component property to be null.

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

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing unset($component->property).

See also https://www.php.net/manual/en/function.unset.php.

public void __unset ( $name )
$name string

The property name

throws yii\base\InvalidCallException

if the property is read only.

                public function __unset($name)
{
    $setter = 'set' . $name;
    if (method_exists($this, $setter)) {
        $this->$setter(null);
        return;
    }
    // behavior property
    $this->ensureBehaviors();
    foreach ($this->_behaviors as $behavior) {
        if ($behavior->canSetProperty($name)) {
            $behavior->$name = null;
            return;
        }
    }
    throw new InvalidCallException('Unsetting an unknown or read-only property: ' . get_class($this) . '::' . $name);
}

            
attachBehavior() public method

Defined in: yii\base\Component::attachBehavior()

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 attached to this component by calling the yii\base\Behavior::attach() method.

See also detachBehavior().

public yii\base\Behavior attachBehavior ( $name, $behavior )
$name string

The name of the behavior.

$behavior string|array|yii\base\Behavior

The behavior configuration. This can be one of the following:

return yii\base\Behavior

The behavior object

                public function attachBehavior($name, $behavior)
{
    $this->ensureBehaviors();
    return $this->attachBehaviorInternal($name, $behavior);
}

            
attachBehaviors() public method

Defined in: yii\base\Component::attachBehaviors()

Attaches a list of behaviors to the component.

Each behavior is indexed by its name and should be a yii\base\Behavior object, a string specifying the behavior class, or an configuration array for creating the behavior.

See also attachBehavior().

public void attachBehaviors ( $behaviors )
$behaviors array

List of behaviors to be attached to the component

                public function attachBehaviors($behaviors)
{
    $this->ensureBehaviors();
    foreach ($behaviors as $name => $behavior) {
        $this->attachBehaviorInternal($name, $behavior);
    }
}

            
behaviors() public method

Defined in: yii\base\Component::behaviors()

Returns a list of behaviors that this component should behave as.

Child classes may override this method to specify the behaviors they want to behave as.

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 yii\base\Behavior. Behaviors can be attached using a name or anonymously. When a name is used as the array key, using this name, the behavior can later be retrieved using getBehavior() or be detached using detachBehavior(). Anonymous behaviors can not be retrieved or detached.

Behaviors declared in this method will be attached to the component automatically (on demand).

public array behaviors ( )
return array

The behavior configurations.

                public function behaviors()
{
    return [];
}

            
canGetProperty() public method

Defined in: yii\base\Component::canGetProperty()

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).

See also canSetProperty().

public boolean canGetProperty ( $name, $checkVars true, $checkBehaviors true )
$name string

The property name

$checkVars boolean

Whether to treat member variables as properties

$checkBehaviors boolean

Whether to treat behaviors' properties as properties of this component

return boolean

Whether the property can be read

                public function canGetProperty($name, $checkVars = true, $checkBehaviors = true)
{
    if (method_exists($this, 'get' . $name) || $checkVars && property_exists($this, $name)) {
        return true;
    } elseif ($checkBehaviors) {
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canGetProperty($name, $checkVars)) {
                return true;
            }
        }
    }
    return false;
}

            
canSetProperty() public method

Defined in: yii\base\Component::canSetProperty()

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).

See also canGetProperty().

public boolean canSetProperty ( $name, $checkVars true, $checkBehaviors true )
$name string

The property name

$checkVars boolean

Whether to treat member variables as properties

$checkBehaviors boolean

Whether to treat behaviors' properties as properties of this component

return boolean

Whether the property can be written

                public function canSetProperty($name, $checkVars = true, $checkBehaviors = true)
{
    if (method_exists($this, 'set' . $name) || $checkVars && property_exists($this, $name)) {
        return true;
    } elseif ($checkBehaviors) {
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->canSetProperty($name, $checkVars)) {
                return true;
            }
        }
    }
    return false;
}

            
className() public static method
Deprecated since 2.0.14. On PHP >=5.5, use ::class instead.

Defined in: yii\base\BaseObject::className()

Returns the fully qualified name of this class.

public static string className ( )
return string

The fully qualified name of this class.

                public static function className()
{
    return get_called_class();
}

            
detachBehavior() public method

Defined in: yii\base\Component::detachBehavior()

Detaches a behavior from the component.

The behavior's yii\base\Behavior::detach() method will be invoked.

public yii\base\Behavior|null detachBehavior ( $name )
$name string

The behavior's name.

return yii\base\Behavior|null

The detached behavior. Null if the behavior does not exist.

                public function detachBehavior($name)
{
    $this->ensureBehaviors();
    if (isset($this->_behaviors[$name])) {
        $behavior = $this->_behaviors[$name];
        unset($this->_behaviors[$name]);
        $behavior->detach();
        return $behavior;
    }
    return null;
}

            
detachBehaviors() public method

Defined in: yii\base\Component::detachBehaviors()

Detaches all behaviors from the component.

public void detachBehaviors ( )

                public function detachBehaviors()
{
    $this->ensureBehaviors();
    foreach ($this->_behaviors as $name => $behavior) {
        $this->detachBehavior($name);
    }
}

            
ensureBehaviors() public method

Defined in: yii\base\Component::ensureBehaviors()

Makes sure that the behaviors declared in behaviors() are attached to this component.

public void ensureBehaviors ( )

                public function ensureBehaviors()
{
    if ($this->_behaviors === null) {
        $this->_behaviors = [];
        foreach ($this->behaviors() as $name => $behavior) {
            $this->attachBehaviorInternal($name, $behavior);
        }
    }
}

            
getBehavior() public method

Defined in: yii\base\Component::getBehavior()

Returns the named behavior object.

public yii\base\Behavior|null getBehavior ( $name )
$name string

The behavior name

return yii\base\Behavior|null

The behavior object, or null if the behavior does not exist

                public function getBehavior($name)
{
    $this->ensureBehaviors();
    return isset($this->_behaviors[$name]) ? $this->_behaviors[$name] : null;
}

            
getBehaviors() public method

Defined in: yii\base\Component::getBehaviors()

Returns all behaviors attached to this component.

public yii\base\Behavior[] getBehaviors ( )
return yii\base\Behavior[]

List of behaviors attached to this component

                public function getBehaviors()
{
    $this->ensureBehaviors();
    return $this->_behaviors;
}

            
getMessageFilePath() protected method

Returns message file path for the specified language and category.

protected string getMessageFilePath ( $language )
$language string

The target language

return string

Path to message file

                protected function getMessageFilePath($language)
{
    $language = (string) $language;
    if ($language !== '' && !preg_match('/^[a-z0-9_-]+$/i', $language)) {
        throw new InvalidArgumentException(sprintf('Invalid language code: "%s".', $language));
    }
    $messageFile = Yii::getAlias($this->basePath) . '/' . $language . '/' . $this->catalog;
    if ($this->useMoFile) {
        $messageFile .= self::MO_FILE_EXT;
    } else {
        $messageFile .= self::PO_FILE_EXT;
    }
    return $messageFile;
}

            
hasEventHandlers() public method

Defined in: yii\base\Component::hasEventHandlers()

Returns a value indicating whether there is any handler attached to the named event.

public boolean hasEventHandlers ( $name )
$name string

The event name

return boolean

Whether there is any handler attached to the event.

                public function hasEventHandlers($name)
{
    $this->ensureBehaviors();
    if (!empty($this->_events[$name])) {
        return true;
    }
    foreach ($this->_eventWildcards as $wildcard => $handlers) {
        if (!empty($handlers) && StringHelper::matchWildcard($wildcard, $name)) {
            return true;
        }
    }
    return Event::hasHandlers($this, $name);
}

            
hasMethod() public method

Defined in: yii\base\Component::hasMethod()

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).
public boolean hasMethod ( $name, $checkBehaviors true )
$name string

The property name

$checkBehaviors boolean

Whether to treat behaviors' methods as methods of this component

return boolean

Whether the method is defined

                public function hasMethod($name, $checkBehaviors = true)
{
    if (method_exists($this, $name)) {
        return true;
    } elseif ($checkBehaviors) {
        $this->ensureBehaviors();
        foreach ($this->_behaviors as $behavior) {
            if ($behavior->hasMethod($name)) {
                return true;
            }
        }
    }
    return false;
}

            
hasProperty() public method

Defined in: yii\base\Component::hasProperty()

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).

See also:

public boolean hasProperty ( $name, $checkVars true, $checkBehaviors true )
$name string

The property name

$checkVars boolean

Whether to treat member variables as properties

$checkBehaviors boolean

Whether to treat behaviors' properties as properties of this component

return boolean

Whether the property is defined

                public function hasProperty($name, $checkVars = true, $checkBehaviors = true)
{
    return $this->canGetProperty($name, $checkVars, $checkBehaviors) || $this->canSetProperty($name, false, $checkBehaviors);
}

            
init() public method

Defined in: yii\i18n\MessageSource::init()

Initializes this component.

public void init ( )

                public function init()
{
    parent::init();
    if ($this->sourceLanguage === null) {
        $this->sourceLanguage = Yii::$app->sourceLanguage;
    }
}

            
loadFallbackMessages() protected method (available since version 2.0.7)

The method is normally called by loadMessages() to load the fallback messages for the language.

Method tries to load the $category messages for the $fallbackLanguage and adds them to the $messages array.

protected array loadFallbackMessages ( $category, $fallbackLanguage, $messages, $originalMessageFile )
$category string

The message category

$fallbackLanguage string

The target fallback language

$messages array

The array of previously loaded translation messages. The keys are original messages, and the values are the translated messages.

$originalMessageFile string

The path to the file with messages. Used to log an error message in case when no translations were found.

return array

The loaded messages. The keys are original messages, and the values are the translated messages.

                protected function loadFallbackMessages($category, $fallbackLanguage, $messages, $originalMessageFile)
{
    $fallbackMessageFile = $this->getMessageFilePath($fallbackLanguage);
    $fallbackMessages = $this->loadMessagesFromFile($fallbackMessageFile, $category);
    if (
        $messages === null && $fallbackMessages === null
        && $fallbackLanguage !== $this->sourceLanguage
        && strpos($this->sourceLanguage, $fallbackLanguage) !== 0
    ) {
        Yii::error("The message file for category '$category' does not exist: $originalMessageFile "
            . "Fallback file does not exist as well: $fallbackMessageFile", __METHOD__);
    } elseif (empty($messages)) {
        return $fallbackMessages;
    } elseif (!empty($fallbackMessages)) {
        foreach ($fallbackMessages as $key => $value) {
            if (!empty($value) && empty($messages[$key])) {
                $messages[$key] = $value;
            }
        }
    }
    return (array) $messages;
}

            
loadMessages() protected method

Loads the message translation for the specified $language and $category.

If translation for specific locale code such as en-US isn't found it tries more generic en. When both are present, the en-US messages will be merged over en. See loadFallbackMessages() for details. If the $language is less specific than $sourceLanguage, the method will try to load the messages for $sourceLanguage. For example: $sourceLanguage is en-GB, $language is en. The method will load the messages for en and merge them over en-GB.

See also:

protected array loadMessages ( $category, $language )
$category string

The message category

$language string

The target language

return array

The loaded messages. The keys are original messages, and the values are translated messages.

                protected function loadMessages($category, $language)
{
    $messageFile = $this->getMessageFilePath($language);
    $messages = $this->loadMessagesFromFile($messageFile, $category);
    $fallbackLanguage = substr($language, 0, 2);
    $fallbackSourceLanguage = substr($this->sourceLanguage, 0, 2);
    if ($fallbackLanguage !== '' && $fallbackLanguage !== $language) {
        $messages = $this->loadFallbackMessages($category, $fallbackLanguage, $messages, $messageFile);
    } elseif ($fallbackSourceLanguage !== '' && $language === $fallbackSourceLanguage) {
        $messages = $this->loadFallbackMessages($category, $this->sourceLanguage, $messages, $messageFile);
    } elseif ($messages === null) {
        Yii::error("The message file for category '$category' does not exist: $messageFile", __METHOD__);
    }
    return (array) $messages;
}

            
loadMessagesFromFile() protected method

Loads the message translation for the specified language and category or returns null if file doesn't exist.

protected array|null loadMessagesFromFile ( $messageFile, $category )
$messageFile string

Path to message file

$category string

The message category

return array|null

Array of messages or null if file not found

                protected function loadMessagesFromFile($messageFile, $category)
{
    if (is_file($messageFile)) {
        if ($this->useMoFile) {
            $gettextFile = new GettextMoFile(['useBigEndian' => $this->useBigEndian]);
        } else {
            $gettextFile = new GettextPoFile();
        }
        $messages = $gettextFile->load($messageFile, $category);
        if (!is_array($messages)) {
            $messages = [];
        }
        return $messages;
    }
    return null;
}

            
off() public method

Defined in: yii\base\Component::off()

Detaches an existing event handler from this component.

This method is the opposite of on().

Note: in case wildcard pattern is passed for event name, only the handlers registered with this wildcard will be removed, while handlers registered with plain names matching this wildcard will remain.

See also on().

public boolean off ( $name, $handler null )
$name string

Event name

$handler callable|null

The event handler to be removed. If it is null, all handlers attached to the named event will be removed.

return boolean

If a handler is found and detached

                public function off($name, $handler = null)
{
    $this->ensureBehaviors();
    if (empty($this->_events[$name]) && empty($this->_eventWildcards[$name])) {
        return false;
    }
    if ($handler === null) {
        unset($this->_events[$name], $this->_eventWildcards[$name]);
        return true;
    }
    $removed = false;
    // plain event names
    if (isset($this->_events[$name])) {
        foreach ($this->_events[$name] as $i => $event) {
            if ($event[0] === $handler) {
                unset($this->_events[$name][$i]);
                $removed = true;
            }
        }
        if ($removed) {
            $this->_events[$name] = array_values($this->_events[$name]);
            return true;
        }
    }
    // wildcard event names
    if (isset($this->_eventWildcards[$name])) {
        foreach ($this->_eventWildcards[$name] as $i => $event) {
            if ($event[0] === $handler) {
                unset($this->_eventWildcards[$name][$i]);
                $removed = true;
            }
        }
        if ($removed) {
            $this->_eventWildcards[$name] = array_values($this->_eventWildcards[$name]);
            // remove empty wildcards to save future redundant regex checks:
            if (empty($this->_eventWildcards[$name])) {
                unset($this->_eventWildcards[$name]);
            }
        }
    }
    return $removed;
}

            
on() public method

Defined in: yii\base\Component::on()

Attaches an event handler to an event.

The event handler must be a valid PHP callback. The following are 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 yii\base\Event object which includes parameters associated with the event.

Since 2.0.14 you can specify event name as a wildcard pattern:

$component->on('event.group.*', function ($event) {
    Yii::trace($event->name . ' is triggered.');
});

See also off().

public void on ( $name, $handler, $data null, $append true )
$name string

The event name

$handler callable

The event handler

$data mixed

The data to be passed to the event handler when the event is triggered. When the event handler is invoked, this data can be accessed via yii\base\Event::$data.

$append boolean

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.

                public function on($name, $handler, $data = null, $append = true)
{
    $this->ensureBehaviors();
    if (strpos($name, '*') !== false) {
        if ($append || empty($this->_eventWildcards[$name])) {
            $this->_eventWildcards[$name][] = [$handler, $data];
        } else {
            array_unshift($this->_eventWildcards[$name], [$handler, $data]);
        }
        return;
    }
    if ($append || empty($this->_events[$name])) {
        $this->_events[$name][] = [$handler, $data];
    } else {
        array_unshift($this->_events[$name], [$handler, $data]);
    }
}

            
translate() public method

Defined in: yii\i18n\MessageSource::translate()

Translates a message to the specified language.

Note that unless $forceTranslation is true, if the target language is the same as the source language, the message will NOT be translated.

If a translation is not found, a missingTranslation event will be triggered.

public string|boolean translate ( $category, $message, $language )
$category string

The message category

$message string

The message to be translated

$language string

The target language

return string|boolean

The translated message or false if translation wasn't found or isn't required

                public function translate($category, $message, $language)
{
    if ($this->forceTranslation || $language !== $this->sourceLanguage) {
        return $this->translateMessage($category, $message, $language);
    }
    return false;
}

            
translateMessage() protected method

Defined in: yii\i18n\MessageSource::translateMessage()

Translates the specified message.

If the message is not found, a missingTranslation event will be triggered. If there is an event handler, it may provide a fallback translation. If no fallback translation is provided this method will return false.

protected string|boolean translateMessage ( $category, $message, $language )
$category string

The category that the message belongs to.

$message string

The message to be translated.

$language string

The target language.

return string|boolean

The translated message or false if translation wasn't found.

                protected function translateMessage($category, $message, $language)
{
    $key = $language . '/' . $category;
    if (!isset($this->_messages[$key])) {
        $this->_messages[$key] = $this->loadMessages($category, $language);
    }
    if (isset($this->_messages[$key][$message]) && $this->_messages[$key][$message] !== '') {
        return $this->_messages[$key][$message];
    } elseif ($this->hasEventHandlers(self::EVENT_MISSING_TRANSLATION)) {
        $event = new MissingTranslationEvent([
            'category' => $category,
            'message' => $message,
            'language' => $language,
        ]);
        $this->trigger(self::EVENT_MISSING_TRANSLATION, $event);
        if ($event->translatedMessage !== null) {
            return $this->_messages[$key][$message] = $event->translatedMessage;
        }
    }
    return $this->_messages[$key][$message] = false;
}

            
trigger() public method

Defined in: yii\base\Component::trigger()

Triggers an event.

This method represents the happening of an event. It invokes all attached handlers for the event including class-level handlers.

public void trigger ( $name, yii\base\Event $event null )
$name string

The event name

$event yii\base\Event|null

The event instance. If not set, a default yii\base\Event object will be created.

                public function trigger($name, Event $event = null)
{
    $this->ensureBehaviors();
    $eventHandlers = [];
    foreach ($this->_eventWildcards as $wildcard => $handlers) {
        if (StringHelper::matchWildcard($wildcard, $name)) {
            $eventHandlers[] = $handlers;
        }
    }
    if (!empty($this->_events[$name])) {
        $eventHandlers[] = $this->_events[$name];
    }
    if (!empty($eventHandlers)) {
        $eventHandlers = call_user_func_array('array_merge', $eventHandlers);
        if ($event === null) {
            $event = new Event();
        }
        if ($event->sender === null) {
            $event->sender = $this;
        }
        $event->handled = false;
        $event->name = $name;
        foreach ($eventHandlers as $handler) {
            $event->data = $handler[1];
            call_user_func($handler[0], $event);
            // stop further handling if the event is handled
            if ($event->handled) {
                return;
            }
        }
    }
    // invoke class-level attached handlers
    Event::trigger($this, $name, $event);
}