HumHub Documentation (unofficial)

ServiceLocator extends Component
in package

Application

ServiceLocator implements a [service locator](https://en.wikipedia.org/wiki/Service_locator_pattern).

To use ServiceLocator, you first need to register component IDs with the corresponding component definitions with the locator by calling [[set()]] or [[setComponents()]]. You can then call [[get()]] to retrieve a component with the specified ID. The locator will automatically instantiate and configure the component according to the definition.

For example,

$locator = new \yii\di\ServiceLocator;
$locator->setComponents([
    'db' => [
        'class' => 'yii\db\Connection',
        'dsn' => 'sqlite:path/to/file.db',
    ],
    'cache' => [
        'class' => 'yii\caching\DbCache',
        'db' => 'db',
    ],
]);

$db = $locator->get('db');  // or $locator->db
$cache = $locator->get('cache');  // or $locator->cache

Because [[\yii\base\Module]] extends from ServiceLocator, modules and the application are all service locators. Modules add tree traversal for service resolution.

For more details and usage information on ServiceLocator, see the guide article on service locators.

Properties

$behaviors : array<string|int, Behavior>
$components : array<string|int, mixed>
$_behaviors : array<string|int, Behavior>|null
$_components : array<string|int, mixed>
$_definitions : array<string|int, mixed>
$_events : array<string|int, mixed>
$_eventWildcards : array<string|int, mixed>

Methods

__call() : mixed: Calls the named method which is not a class method.
__clone() : mixed: This method is called after the object is created by cloning an existing one.
__construct() : mixed: Constructor.
__get() : mixed: Getter magic method.
__isset() : bool: Checks if a property value is null.
__set() : mixed: Sets the value of a component property.
__unset() : mixed: Sets a component property to be null.
attachBehavior() : Behavior: Attaches a behavior to this component.
attachBehaviors() : mixed: Attaches a list of behaviors to the component.
behaviors() : array<string|int, mixed>: Returns a list of behaviors that this component should behave as.
canGetProperty() : bool: Returns a value indicating whether a property can be read.
canSetProperty() : bool: Returns a value indicating whether a property can be set.
className() : string: Returns the fully qualified name of this class.
clear() : mixed: Removes the component from the locator.
detachBehavior() : Behavior|null: Detaches a behavior from the component.
detachBehaviors() : mixed: Detaches all behaviors from the component.
ensureBehaviors() : mixed: Makes sure that the behaviors declared in [[behaviors()]] are attached to this component.
get() : object|null: Returns the component instance with the specified ID.
getBehavior() : Behavior|null: Returns the named behavior object.
getBehaviors() : array<string|int, Behavior>: Returns all behaviors attached to this component.
getComponents() : array<string|int, mixed>: Returns the list of the component definitions or the loaded component instances.
has() : bool: Returns a value indicating whether the locator has the specified component definition or has instantiated the component.
hasEventHandlers() : bool: Returns a value indicating whether there is any handler attached to the named event.
hasMethod() : bool: Returns a value indicating whether a method is defined.
hasProperty() : bool: Returns a value indicating whether a property is defined for this component.
init() : mixed: Initializes the object.
off() : bool: Detaches an existing event handler from this component.
on() : mixed: Attaches an event handler to an event.
set() : mixed: Registers a component definition with this locator.
setComponents() : mixed: Registers a set of component definitions in this locator.
trigger() : mixed: Triggers an event.
attachBehaviorInternal() : Behavior: Attaches a behavior to this component.

$behaviors read-only


    public
        array<string|int, Behavior>
    $behaviors

List of behaviors attached to this component.

$components


    public
        array<string|int, mixed>
    $components

The list of the component definitions or the loaded component instances (ID => definition or instance).

$_behaviors


    private
        array<string|int, Behavior>|null
    $_behaviors

the attached behaviors (behavior name => behavior). This is null when not initialized.

$_components


    private
        array<string|int, mixed>
    $_components
     = []

shared component instances indexed by their IDs

$_definitions


    private
        array<string|int, mixed>
    $_definitions
     = []

component definitions indexed by their IDs

$_events


    private
        array<string|int, mixed>
    $_events
     = []

the attached event handlers (event name => handlers)

$_eventWildcards


    private
        array<string|int, mixed>
    $_eventWildcards
     = []

the event handlers attached for wildcard patterns (event name wildcard => handlers)

__call()

Calls the named method which is not a class method.


    public
                    __call(string $name, array<string|int, mixed> $params) : mixed

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.

Parameters

$name : string: the method name
$params : array<string|int, mixed>: method parameters

Return values

mixed —

the method return value

__clone()

This method is called after the object is created by cloning an existing one.


    public
                    __clone() : mixed

It removes all behaviors because they are attached to the old object.

__construct()

Constructor.


    public
                    __construct([array<string|int, mixed> $config = [] ]) : mixed

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.

Parameters

$config : array<string|int, mixed> = []: name-value pairs that will be used to initialize the object properties

__get()

Getter magic method.


    public
                    __get(string $name) : mixed

This method is overridden to support accessing components like reading properties.

Parameters

$name : string: component or property name

Return values

mixed —

the named property value

__isset()

Checks if a property value is null.


    public
                    __isset(string $name) : bool

This method overrides the parent implementation by checking if the named component is loaded.

Parameters

$name : string: the property name or the event name

Return values

bool —

whether the property value is null

__set()

Sets the value of a component property.


    public
                    __set(string $name, mixed $value) : mixed

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;.

Parameters

$name : string: the property name or the event name
$value : mixed: the property value

__unset()

Sets a component property to be null.


    public
                    __unset(string $name) : mixed

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).

Parameters

$name : string: the property name

attachBehavior()

Attaches a behavior to this component.


    public
                    attachBehavior(string $name, string|array<string|int, mixed>|Behavior $behavior) : Behavior

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.

Parameters

$name : string

the name of the behavior.

$behavior : string|array<string|int, mixed>|Behavior

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

a [[Behavior]] object
a string specifying the behavior class
an object configuration array that will be passed to [[Yii::createObject()]] to create the behavior object.

Return values

Behavior —

the behavior object

attachBehaviors()

Attaches a list of behaviors to the component.


    public
                    attachBehaviors(array<string|int, mixed> $behaviors) : mixed

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.

Parameters

$behaviors : array<string|int, mixed>: list of behaviors to be attached to the component

behaviors()

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


    public
                    behaviors() : array<string|int, mixed>

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 [[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).

Return values

array<string|int, mixed> —

the behavior configurations.

canGetProperty()

Returns a value indicating whether a property can be read.


    public
                    canGetProperty(string $name[, bool $checkVars = true ][, bool $checkBehaviors = true ]) : bool

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).

Parameters

$name : string: the property name
$checkVars : bool = true: whether to treat member variables as properties
$checkBehaviors : bool = true: whether to treat behaviors' properties as properties of this component

Return values

bool —

whether the property can be read

canSetProperty()

Returns a value indicating whether a property can be set.


    public
                    canSetProperty(string $name[, bool $checkVars = true ][, bool $checkBehaviors = true ]) : bool

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).

Parameters

$name : string: the property name
$checkVars : bool = true: whether to treat member variables as properties
$checkBehaviors : bool = true: whether to treat behaviors' properties as properties of this component

Return values

bool —

whether the property can be written

className()

Returns the fully qualified name of this class.


    public
            static        className() : string

Return values

string —

the fully qualified name of this class.

clear()

Removes the component from the locator.


    public
                    clear(string $id) : mixed

Parameters

$id : string: the component ID

detachBehavior()

Detaches a behavior from the component.


    public
                    detachBehavior(string $name) : Behavior|null

The behavior's [[Behavior::detach()]] method will be invoked.

Parameters

$name : string: the behavior's name.

Return values

Behavior|null —

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

detachBehaviors()

Detaches all behaviors from the component.


    public
                    detachBehaviors() : mixed

ensureBehaviors()

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


    public
                    ensureBehaviors() : mixed

get()

Returns the component instance with the specified ID.


    public
                    get(string $id[, bool $throwException = true ]) : object|null

Parameters

$id : string: component ID (e.g. db).
$throwException : bool = true: whether to throw an exception if $id is not registered with the locator before.

Return values

object|null —

the component of the specified ID. If $throwException is false and $id is not registered before, null will be returned.

getBehavior()

Returns the named behavior object.


    public
                    getBehavior(string $name) : Behavior|null

Parameters

$name : string: the behavior name

Return values

Behavior|null —

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

getBehaviors()

Returns all behaviors attached to this component.


    public
                    getBehaviors() : array<string|int, Behavior>

Return values

array<string|int, Behavior> —

list of behaviors attached to this component

getComponents()

Returns the list of the component definitions or the loaded component instances.


    public
                    getComponents([bool $returnDefinitions = true ]) : array<string|int, mixed>

Parameters

$returnDefinitions : bool = true: whether to return component definitions instead of the loaded component instances.

Return values

array<string|int, mixed> —

the list of the component definitions or the loaded component instances (ID => definition or instance).

has()

Returns a value indicating whether the locator has the specified component definition or has instantiated the component.


    public
                    has(string $id[, bool $checkInstance = false ]) : bool

This method may return different results depending on the value of $checkInstance.

If $checkInstance is false (default), the method will return a value indicating whether the locator has the specified component definition.
If $checkInstance is true, the method will return a value indicating whether the locator has instantiated the specified component.

Parameters

$id : string: component ID (e.g. db).
$checkInstance : bool = false: whether the method should check if the component is shared and instantiated.

Return values

bool —

whether the locator has the specified component definition or has instantiated the component.

hasEventHandlers()

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


    public
                    hasEventHandlers(string $name) : bool

Parameters

$name : string: the event name

Return values

bool —

whether there is any handler attached to the event.

hasMethod()

Returns a value indicating whether a method is defined.


    public
                    hasMethod(string $name[, bool $checkBehaviors = true ]) : bool

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).

Parameters

$name : string: the property name
$checkBehaviors : bool = true: whether to treat behaviors' methods as methods of this component

Return values

bool —

whether the method is defined

hasProperty()

Returns a value indicating whether a property is defined for this component.


    public
                    hasProperty(string $name[, bool $checkVars = true ][, bool $checkBehaviors = true ]) : bool

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).

Parameters

$name : string: the property name
$checkVars : bool = true: whether to treat member variables as properties
$checkBehaviors : bool = true: whether to treat behaviors' properties as properties of this component

Return values

bool —

whether the property is defined

init()

Initializes the object.


    public
                    init() : mixed

This method is invoked at the end of the constructor after the object is initialized with the given configuration.

off()

Detaches an existing event handler from this component.


    public
                    off(string $name[, callable|null $handler = null ]) : bool

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.

Parameters

$name : string: event name
$handler : callable|null = null: the event handler to be removed. If it is null, all handlers attached to the named event will be removed.

Return values

bool —

if a handler is found and detached

on()

Attaches an event handler to an event.


    public
                    on(string $name, callable $handler[, mixed $data = null ][, bool $append = true ]) : mixed

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 [[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.');
});

Parameters

$name : string: the event name
$handler : callable: the event handler
$data : mixed = null: 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 [[Event::data]].
$append : bool = true: 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.

set()

Registers a component definition with this locator.


    public
                    set(string $id, mixed $definition) : mixed

For example,

// a class name
$locator->set('cache', 'yii\caching\FileCache');

// a configuration array
$locator->set('db', [
    'class' => 'yii\db\Connection',
    'dsn' => 'mysql:host=127.0.0.1;dbname=demo',
    'username' => 'root',
    'password' => '',
    'charset' => 'utf8',
]);

// an anonymous function
$locator->set('cache', function ($params) {
    return new \yii\caching\FileCache;
});

// an instance
$locator->set('cache', new \yii\caching\FileCache);

If a component definition with the same ID already exists, it will be overwritten.

Parameters

$id : string

component ID (e.g. db).

$definition : mixed

the component definition to be registered with this locator. It can be one of the following:

a class name
a configuration array: the array contains name-value pairs that will be used to initialize the property values of the newly created object when [[get()]] is called. The class element is required and stands for the the class of the object to be created.
a PHP callable: either an anonymous function or an array representing a class method (e.g. ['Foo', 'bar']). The callable will be called by [[get()]] to return an object associated with the specified component ID.
an object: When [[get()]] is called, this object will be returned.

setComponents()

Registers a set of component definitions in this locator.


    public
                    setComponents(array<string|int, mixed> $components) : mixed

This is the bulk version of [[set()]]. The parameter should be an array whose keys are component IDs and values the corresponding component definitions.

For more details on how to specify component IDs and definitions, please refer to [[set()]].

If a component definition with the same ID already exists, it will be overwritten.

The following is an example for registering two component definitions:

[
    'db' => [
        'class' => 'yii\db\Connection',
        'dsn' => 'sqlite:path/to/file.db',
    ],
    'cache' => [
        'class' => 'yii\caching\DbCache',
        'db' => 'db',
    ],
]

Parameters

$components : array<string|int, mixed>: component definitions or instances

trigger()

Triggers an event.


    public
                    trigger(string $name[, Event|null $event = null ]) : mixed

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

Parameters

$name : string: the event name
$event : Event|null = null: the event instance. If not set, a default [[Event]] object will be created.

attachBehaviorInternal()

Attaches a behavior to this component.


    private
                    attachBehaviorInternal(string|int $name, string|array<string|int, mixed>|Behavior $behavior) : Behavior

Parameters

$name : string|int: 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.
$behavior : string|array<string|int, mixed>|Behavior: the behavior to be attached

Return values

Behavior —

the attached behavior.

ServiceLocator extends Component in package Application

Tags

Table of Contents

Properties

Methods

Properties

$behaviors read-only

$components

$_behaviors

$_components

$_definitions

$_events

$_eventWildcards

Tags

Methods

__call()

Parameters

Tags

Return values

__clone()

__construct()

Parameters

__get()

Parameters

Return values

__isset()

Parameters

Return values

__set()

Parameters

Tags

__unset()

Parameters

Tags

attachBehavior()

Parameters

Tags

Return values

attachBehaviors()

Parameters

Tags

behaviors()

Return values

canGetProperty()

Parameters

Tags

Return values

canSetProperty()

Parameters

Tags

Return values

className()

Tags

Return values

clear()

Parameters

detachBehavior()

Parameters

Return values

detachBehaviors()

ensureBehaviors()

get()

Parameters

Tags

Return values

getBehavior()

Parameters

Return values

getBehaviors()

Return values

getComponents()

Parameters

Return values

ServiceLocator extends Component
in package

Application