Class Component

Base class for an individual Component. Components provide reusable bits of controller logic that can be composed into a controller. Components also provide request life-cycle callbacks for injecting logic at specific points.

Initialize hook

Like Controller and Table, this class has an initialize() hook that you can use to add custom 'constructor' logic. It is important to remember that each request (and sub-request) will only make one instance of any given component.

Life cycle callbacks

Components can provide several callbacks that are fired at various stages of the request cycle. The available callbacks are:

  • beforeFilter(Event $event) Called before the controller's beforeFilter method by default.
  • startup(Event $event) Called after the controller's beforeFilter method, and before the controller action is called.
  • beforeRender(Event $event) Called before the Controller beforeRender, and before the view class is loaded.
  • shutdown(Event $event) Called after the action is complete and the view has been rendered but before Controller::afterFilter().
  • beforeRedirect(Event $event $url, Response $response) Called before a redirect is done. Allows you to change the URL that will be redirected to by returning a Response instance with new URL set using Response::location(). Redirection can be prevented by stopping the event propagation.

While the controller is not an explicit argument for the callback methods it is the subject of each event and can be fetched using Event::getSubject().

Namespace: Cake\Controller

Properties summary

  • $_componentMap protected
    array

    A component lookup table used to lazy load component objects.

  • $_config protected
    array

    Runtime config

  • $_configInitialized protected
    bool

    Whether the config property has already been configured with defaults

  • $_defaultConfig protected
    array

    Default config

  • $_registry protected
    \Cake\Controller\ComponentRegistry

    Component registry class used to lazy load components.

  • $components public
    array

    Other Components this component uses.

  • $request public
    \Cake\Http\ServerRequest

    Request object

  • $response public
    \Cake\Http\Response

    Response object

Method Summary

  • __construct() public

    Constructor

  • __debugInfo() public

    Returns an array that can be used to describe the internal state of this object.

  • __get() public

    Magic method for lazy loading $components.

  • _configDelete() protected

    Deletes a single config key.

  • _configRead() protected

    Reads a config key.

  • _configWrite() protected

    Writes a config key.

  • config() public

    Gets/Sets the config.

  • configShallow() public

    Merge provided config with existing config. Unlike config() which does a recursive merge for nested keys, this method does a simple merge.

  • getConfig() public

    Returns the config.

  • getConfigOrFail() public

    Returns the config for this specific key.

  • getController() public

    Get the controller this component is bound to.

  • implementedEvents() public

    Get the Controller callbacks this Component is interested in.

  • initialize() public

    Constructor hook method.

  • log() public

    Convenience method to write a message to Log. See Log::write() for more information on writing to logs.

  • setConfig() public

    Sets the config.

Method Detail

__construct() public 

__construct(\Cake\Controller\ComponentRegistry $registry, array $config)

Constructor

Parameters

\Cake\Controller\ComponentRegistry $registry

A ComponentRegistry this component can use to lazy load its components

array $config optional

Array of configuration settings.

__debugInfo() public 

__debugInfo()

Returns an array that can be used to describe the internal state of this object.

Returns

array

__get() public 

__get(mixed $name)

Magic method for lazy loading $components.

Parameters

string $name

Name of component to get.

Returns

\Cake\Controller\Component|null

A Component object or null.

_configDelete() protected 

_configDelete(mixed $key)

Deletes a single config key.

Parameters

string $key

Key to delete.

Throws

Cake\Core\Exception\Exception
if attempting to clobber existing config

_configRead() protected 

_configRead(mixed $key)

Reads a config key.

Parameters

string|null $key

Key to read.

Returns

mixed

_configWrite() protected 

_configWrite(mixed $key, mixed $value, mixed $merge)

Writes a config key.

Parameters

string|array $key

Key to write to.

mixed $value

Value to write.

bool|string $merge optional

True to merge recursively, 'shallow' for simple merge, false to overwrite, defaults to false.

Throws

Cake\Core\Exception\Exception
if attempting to clobber existing config

config() public 

config(mixed $key, mixed $value, mixed $merge)

Gets/Sets the config.

Usage

Reading the whole config:

$this->config();

Reading a specific value:

$this->config('key');

Reading a nested value:

$this->config('some.nested.key');

Setting a specific value:

$this->config('key', $value);

Setting a nested value:

$this->config('some.nested.key', $value);

Updating multiple config settings at the same time:

$this->config(['one' => 'value', 'another' => 'value']);

Parameters

string|array|null $key optional

The key to get/set, or a complete array of configs.

mixed|null $value optional

The value to set.

bool $merge optional

Whether to recursively merge or overwrite existing config, defaults to true.

Returns

mixed

Config value being read, or the object itself on write operations.

Throws

Cake\Core\Exception\Exception
When trying to set a key that is invalid.

configShallow() public 

configShallow(mixed $key, mixed $value)

Merge provided config with existing config. Unlike config() which does a recursive merge for nested keys, this method does a simple merge.

Setting a specific value:

$this->configShallow('key', $value);

Setting a nested value:

$this->configShallow('some.nested.key', $value);

Updating multiple config settings at the same time:

$this->configShallow(['one' => 'value', 'another' => 'value']);

Parameters

string|array $key

The key to set, or a complete array of configs.

mixed|null $value optional

The value to set.

Returns

$this

getConfig() public 

getConfig(mixed $key, mixed $default)

Returns the config.

Usage

Reading the whole config:

$this->getConfig();

Reading a specific value:

$this->getConfig('key');

Reading a nested value:

$this->getConfig('some.nested.key');

Reading with default value:

$this->getConfig('some-key', 'default-value');

Parameters

string|null $key optional

The key to get or null for the whole config.

mixed|null $default optional

The return value when the key does not exist.

Returns

mixed|null

Configuration data at the named key or null if the key does not exist.

getConfigOrFail() public 

getConfigOrFail(mixed $key)

Returns the config for this specific key.

The config value for this key must exist, it can never be null.

Parameters

string|null $key

The key to get.

Returns

mixed

Configuration data at the named key

Throws

InvalidArgumentException

getController() public 

getController()

Get the controller this component is bound to.

Returns

\Cake\Controller\Controller

The bound controller.

implementedEvents() public 

implementedEvents()

Get the Controller callbacks this Component is interested in.

Uses Conventions to map controller events to standard component callback method names. By defining one of the callback methods a component is assumed to be interested in the related event.

Override this method if you need to add non-conventional event listeners. Or if you want components to listen to non-standard events.

Returns

array

initialize() public 

initialize(array $config)

Constructor hook method.

Implement this method to avoid having to overwrite the constructor and call parent.

Parameters

array $config

The configuration settings provided to this component.

log() public 

log(mixed $message, mixed $level, mixed $context)

Convenience method to write a message to Log. See Log::write() for more information on writing to logs.

Parameters

mixed $message

Log message.

int|string $level optional

Error level.

string|array $context optional

Additional log data relevant to this message.

Returns

bool

Success of log write.

setConfig() public 

setConfig(mixed $key, mixed $value, mixed $merge)

Sets the config.

Usage

Setting a specific value:

$this->setConfig('key', $value);

Setting a nested value:

$this->setConfig('some.nested.key', $value);

Updating multiple config settings at the same time:

$this->setConfig(['one' => 'value', 'another' => 'value']);

Parameters

string|array $key

The key to set, or a complete array of configs.

mixed|null $value optional

The value to set.

bool $merge optional

Whether to recursively merge or overwrite existing config, defaults to true.

Returns

$this

Throws

Cake\Core\Exception\Exception
When trying to set a key that is invalid.

Property Detail

$_componentMap protected

A component lookup table used to lazy load component objects.

Type

array

$_config protected

Runtime config

Type

array

$_configInitialized protected

Whether the config property has already been configured with defaults

Type

bool

$_defaultConfig protected

Default config

These are merged with user-provided config when the component is used.

Type

array

$_registry protected

Component registry class used to lazy load components.

Type

\Cake\Controller\ComponentRegistry

$components public

Other Components this component uses.

Type

array

$request public

Request object

Type

\Cake\Http\ServerRequest

$response public

Response object

Type

\Cake\Http\Response

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https://api.cakephp.org/3.9/class-Cake.Controller.Component.html