# Abstract Class yii\log\Target

Inheritance | yii\log\Target » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable
Subclasses | yii\debug\LogTarget, yii\elasticsearch\ElasticsearchTarget, yii\log\DbTarget, yii\log\EmailTarget, yii\log\FileTarget, yii\log\SyslogTarget, yii\mongodb\log\MongoDbTarget
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/log/Target.php

Target is the base class for all log target classes.

A log target object will filter the messages logged by yii\log\Logger according to its $levels and $categories properties. It may also export the filtered messages to specific destination defined by the target, such as emails, files.

Level filter and category filter are combinatorial, i.e., only messages satisfying both filter conditions will be handled. Additionally, you may specify $except to exclude messages of certain categories.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$categories | array | List of message categories that this target is interested in. | yii\log\Target
$enabled | boolean | Indicates whether this log target is enabled. Defaults to true. Note that the type of this property differs in getter and setter. See getEnabled() and setEnabled() for details. | yii\log\Target
$except | array | List of message categories that this target is NOT interested in. | yii\log\Target
$exportInterval | integer | How many messages should be accumulated before they are exported. | yii\log\Target
$levels | integer | The message levels that this target is interested in. This is a bitmap of level values. Defaults to 0, meaning all available levels. Note that the type of this property differs in getter and setter. See getLevels() and setLevels() for details. For more details and usage information on Target, see the guide article on logging & targets. | yii\log\Target
$logVars | array | List of the PHP predefined variables that should be logged in a message. | yii\log\Target
$maskVars | array | List of the PHP predefined variables that should NOT be logged "as is" and should always be replaced with a mask `***` before logging, when exist. | yii\log\Target
$messages | array | The messages that are retrieved from the logger so far by this log target. | yii\log\Target
$microtime | boolean | Whether to log time with microseconds. | yii\log\Target
$prefix | callable | A PHP callable that returns a string to be prefixed to every exported message. | yii\log\Target

## 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
collect() | Processes the given log messages. | yii\log\Target
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
export() | Exports log $messages to a specific destination. | yii\log\Target
filterMessages() | Filters the given messages according to their categories and levels. | yii\log\Target
formatMessage() | Formats a log message for display as a string. | yii\log\Target
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getEnabled() | Check whether the log target is enabled. | yii\log\Target
getLevels() |  | yii\log\Target
getMessagePrefix() | Returns a string to be prefixed to the given message. | yii\log\Target
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 the object. | yii\base\BaseObject
off() | Detaches an existing event handler from this component. | yii\base\Component
on() | Attaches an event handler to an event. | yii\base\Component
setEnabled() | Sets a value indicating whether this log target is enabled. | yii\log\Target
setLevels() | Sets the message levels that this target is interested in. | yii\log\Target
trigger() | Triggers an event. | yii\base\Component

## Protected Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
getContextMessage() | Generates the context information to be logged. | yii\log\Target
getTime() | Returns formatted ('Y-m-d H:i:s') timestamp for message. | yii\log\Target

## Property Details

$categories public property

List of message categories that this target is interested in. Defaults to empty, meaning all categories. You can use an asterisk at the end of a category so that the category may be used to match those categories sharing the same common prefix. For example, 'yii\db*' will match categories starting with 'yii\db\', such as 'yii\db\Connection'.

public array $categories = []
$enabled public property

Indicates whether this log target is enabled. Defaults to true. Note that the type of this property differs in getter and setter. See getEnabled() and setEnabled() for details.

public boolean $enabled = null
$except public property

List of message categories that this target is NOT interested in. Defaults to empty, meaning no uninteresting messages. If this property is not empty, then any category listed here will be excluded from $categories. You can use an asterisk at the end of a category so that the category can be used to match those categories sharing the same common prefix. For example, 'yii\db*' will match categories starting with 'yii\db\', such as 'yii\db\Connection'.

See also $categories.

public array $except = []
$exportInterval public property

How many messages should be accumulated before they are exported. Defaults to 1000. Note that messages will always be exported when the application terminates. Set this property to be 0 if you don't want to export messages until the application terminates.

public integer $exportInterval = 1000
$levels public property

The message levels that this target is interested in. This is a bitmap of level values. Defaults to 0, meaning all available levels. Note that the type of this property differs in getter and setter. See getLevels() and setLevels() for details.

For more details and usage information on Target, see the guide article on logging & targets.

public integer $levels = null
$logVars public property

List of the PHP predefined variables that should be logged in a message. Note that a variable must be accessible via `$GLOBALS`. Otherwise it won't be logged.

Defaults to `['_GET', '_POST', '_FILES', '_COOKIE', '_SESSION', '_SERVER']`.

Since version 2.0.9 additional syntax can be used: Each element could be specified as one of the following:

- `var` - `var` will be logged.
- `var.key` - only `var[key]` key will be logged.
- `!var.key` - `var[key]` key will be excluded.

Note that if you need $_SESSION to logged regardless if session was used you have to open it right at the start of your request.

See also yii\helpers\ArrayHelper::filter().

public array $logVars = ['_GET', '_POST', '_FILES', '_COOKIE', '_SESSION', '_SERVER']
$maskVars public property (available since version 2.0.16)

List of the PHP predefined variables that should NOT be logged "as is" and should always be replaced with a mask `***` before logging, when exist.

Defaults to `[ '_SERVER.HTTP_AUTHORIZATION', '_SERVER.PHP_AUTH_USER', '_SERVER.PHP_AUTH_PW']`

Each element could be specified as one of the following:

- `var` - `var` will be logged as `***`
- `var.key` - only `var[key]` will be logged as `***`

public array $maskVars = ['_SERVER.HTTP_AUTHORIZATION', '_SERVER.PHP_AUTH_USER', '_SERVER.PHP_AUTH_PW']
$messages public property

The messages that are retrieved from the logger so far by this log target. Please refer to yii\log\Logger::$messages for the details about the message structure.

public array $messages = []
$microtime public property (available since version 2.0.13)

Whether to log time with microseconds. Defaults to false.

public boolean $microtime = false
$prefix public property

A PHP callable that returns a string to be prefixed to every exported message.

If not set, getMessagePrefix() will be used, which prefixes the message with context information such as user IP, user ID and session ID.

The signature of the callable should be `function ($message)`.

public callable $prefix = null

## Method Details

collect() public method

Processes the given log messages.

This method will filter the given messages with $levels and $categories. And if requested, it will also export the filtering result to specific medium (e.g. email).

public void collect ( $messages, $final )
$messages | array | Log messages to be processed. See yii\log\Logger::$messages for the structure of each message.
$final | boolean | Whether this method is called at the end of the current application

export() public abstract method

Exports log $messages to a specific destination.

Child classes must implement this method.

public abstract void export ( )

filterMessages() public static method

Filters the given messages according to their categories and levels.

public static array filterMessages ( $messages, $levels = 0, $categories = [], $except = [] )
$messages | array | Messages to be filtered. The message structure follows that in yii\log\Logger::$messages.
$levels | integer | The message levels to filter by. This is a bitmap of level values. Value 0 means allowing all levels.
$categories | array | The message categories to filter by. If empty, it means all categories are allowed.
$except | array | The message categories to exclude. If empty, it means all categories are allowed.
return | array | The filtered messages.

formatMessage() public method

Formats a log message for display as a string.

public string formatMessage ( $message )
$message | array | The log message to be formatted. The message structure follows that in yii\log\Logger::$messages.
return | string | The formatted message

getContextMessage() protected method

Generates the context information to be logged.

The default implementation will dump user information, system variables, etc.

protected string getContextMessage ( )
return | string | The context information. If an empty string, it means no context information.

getEnabled() public method

Check whether the log target is enabled.

public boolean getEnabled ( )
return | boolean | A value indicating whether this log target is enabled.

getLevels() public method

public integer getLevels ( )
return | integer | The message levels that this target is interested in. This is a bitmap of level values. Defaults to 0, meaning all available levels.

getMessagePrefix() public method

Returns a string to be prefixed to the given message.

If $prefix is configured it will return the result of the callback. The default implementation will return user IP, user ID and session ID as a prefix.

public string getMessagePrefix ( $message )
$message | array | The message being exported. The message structure follows that in yii\log\Logger::$messages.
return | string | The prefix string

getTime() protected method (available since version 2.0.13)

Returns formatted ('Y-m-d H:i:s') timestamp for message.

If $microtime is configured to true it will return format 'Y-m-d H:i:s.u'.

protected string getTime ( $timestamp )
$timestamp | float |

setEnabled() public method

Sets a value indicating whether this log target is enabled.

public void setEnabled ( $value )
$value | boolean|callable | A boolean value or a callable to obtain the value from. The callable value is available since version 2.0.13. A callable may be used to determine whether the log target should be enabled in a dynamic way. For example, to only enable a log if the current user is logged in you can configure the target as follows:
    'enabled' => function() {
        return !Yii::$app->user->isGuest;
    }

setLevels() public method

Sets the message levels that this target is interested in.

The parameter can be either an array of interested level names or an integer representing the bitmap of the interested level values. Valid level names include: 'error', 'warning', 'info', 'trace' and 'profile'; valid level values include: yii\log\Logger::LEVEL_ERROR, yii\log\Logger::LEVEL_WARNING, yii\log\Logger::LEVEL_INFO, yii\log\Logger::LEVEL_TRACE and yii\log\Logger::LEVEL_PROFILE.

For example,

    ['error', 'warning']
    // which is equivalent to:
    Logger::LEVEL_ERROR | Logger::LEVEL_WARNING

public void setLevels ( $levels )
$levels | array|integer | Message levels that this target is interested in.
throws | yii\base\InvalidConfigException | if $levels value is not correct.