# Class yii\behaviors\SluggableBehavior

Inheritance | yii\behaviors\SluggableBehavior » yii\behaviors\AttributeBehavior » yii\base\Behavior » yii\base\BaseObject
Implements | yii\base\Configurable
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/behaviors/SluggableBehavior.php

SluggableBehavior automatically fills the specified attribute with a value that can be used a slug in a URL.

Note: This behavior relies on php-intl extension for transliteration. If it is not installed it falls back to replacements defined in yii\helpers\Inflector::$transliteration.

To use SluggableBehavior, insert the following code to your ActiveRecord class:

    use yii\behaviors\SluggableBehavior;

    public function behaviors()
    {
        return [
            [
                'class' => SluggableBehavior::className(),
                'attribute' => 'title',
                // 'slugAttribute' => 'slug',
            ],
        ];
    }

By default, SluggableBehavior will fill the `slug` attribute with a value that can be used a slug in a URL when the associated AR object is being validated.

Because attribute values will be set automatically by this behavior, they are usually not user input and should therefore not be validated, i.e. the `slug` attribute should not appear in the rules() method of the model.

If your attribute name is different, you may configure the $slugAttribute property like the following:

    public function behaviors()
    {
        return [
            [
                'class' => SluggableBehavior::className(),
                'slugAttribute' => 'alias',
            ],
        ];
    }

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$attribute | string|array|null | The attribute or list of attributes whose value will be converted into a slug or `null` meaning that the `$value` property will be used to generate a slug. | yii\behaviors\SluggableBehavior
$attributes | array | List of attributes that are to be automatically filled with the value specified via $value. | yii\behaviors\AttributeBehavior
$ensureUnique | boolean | Whether to ensure generated slug value to be unique among owner class records. | yii\behaviors\SluggableBehavior
$immutable | boolean | Whether to generate a new slug if it has already been generated before. | yii\behaviors\SluggableBehavior
$owner | yii\base\Component|null | The owner of this behavior | yii\base\Behavior
$preserveNonEmptyValues | boolean | Whether to preserve non-empty attribute values. | yii\behaviors\AttributeBehavior
$skipOnEmpty | boolean | Whether to skip slug generation if $attribute is null or an empty string. | yii\behaviors\SluggableBehavior
$skipUpdateOnClean | boolean | Whether to skip this behavior when the `$owner` has not been modified | yii\behaviors\AttributeBehavior
$slugAttribute | string | The attribute that will receive the slug value | yii\behaviors\SluggableBehavior
$uniqueSlugGenerator | callable | Slug unique value generator. | yii\behaviors\SluggableBehavior
$uniqueValidator | array | Configuration for slug uniqueness validator. | yii\behaviors\SluggableBehavior
$value | callable|string|null | The value that will be used as a slug. | yii\behaviors\SluggableBehavior

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\BaseObject
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of an object property. | yii\base\BaseObject
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\BaseObject
__set() | Sets value of an object property. | yii\base\BaseObject
__unset() | Sets an object property to null. | yii\base\BaseObject
attach() | Attaches the behavior object to the component. | yii\base\Behavior
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\BaseObject
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\BaseObject
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
detach() | Detaches the behavior object from the component. | yii\base\Behavior
evaluateAttributes() | Evaluates the attribute value and assigns it to the current attributes. | yii\behaviors\AttributeBehavior
events() | Declares event handlers for the $owner's events. | yii\base\Behavior
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\BaseObject
hasProperty() | Returns a value indicating whether a property is defined. | yii\base\BaseObject
init() | Initializes the object. | yii\behaviors\SluggableBehavior

## Protected Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
generateSlug() | This method is called by getValue() to generate the slug. | yii\behaviors\SluggableBehavior
generateUniqueSlug() | Generates slug using configured callback or increment of iteration. | yii\behaviors\SluggableBehavior
getValue() | Returns the value for the current attributes. | yii\behaviors\SluggableBehavior
isEmpty() | Checks if $slugPart is empty string or null. | yii\behaviors\SluggableBehavior
isNewSlugNeeded() | Checks whether the new slug generation is needed This method is called by getValue() to check whether the new slug generation is needed. | yii\behaviors\SluggableBehavior
makeUnique() | This method is called by getValue() when $ensureUnique is true to generate the unique slug. | yii\behaviors\SluggableBehavior
validateSlug() | Checks if given slug value is unique. | yii\behaviors\SluggableBehavior

## Property Details

$attribute public property

The attribute or list of attributes whose value will be converted into a slug or `null` meaning that the `$value` property will be used to generate a slug.

public string|array|null $attribute = null
$ensureUnique public property

Whether to ensure generated slug value to be unique among owner class records. If enabled behavior will validate slug uniqueness automatically. If validation fails it will attempt generating unique slug value from based one until success.

public boolean $ensureUnique = false
$immutable public property (available since version 2.0.2)

Whether to generate a new slug if it has already been generated before. If true, the behavior will not generate a new slug even if $attribute is changed.

public boolean $immutable = false
$skipOnEmpty public property (available since version 2.0.13)

Whether to skip slug generation if $attribute is null or an empty string. If true, the behaviour will not generate a new slug if $attribute is null or an empty string.

public boolean $skipOnEmpty = false
$slugAttribute public property

The attribute that will receive the slug value

public string $slugAttribute = 'slug'
$uniqueSlugGenerator public property

Slug unique value generator. It is used in case $ensureUnique enabled and generated slug is not unique. This should be a PHP callable with following signature:

    function ($baseSlug, $iteration, $model)
    {
        // return uniqueSlug
    }

If not set unique slug will be generated adding incrementing suffix to the base slug.

public callable $uniqueSlugGenerator = null
$uniqueValidator public property

Configuration for slug uniqueness validator. Parameter 'class' may be omitted - by default yii\validators\UniqueValidator will be used.

See also yii\validators\UniqueValidator.

public array $uniqueValidator = []
$value public property

The value that will be used as a slug. This can be an anonymous function or an arbitrary value or null. If the former, the return value of the function will be used as a slug. If `null` then the `$attribute` property will be used to generate a slug. The signature of the function should be as follows,

    function ($event)
    {
        // return slug
    }

public callable|string|null $value = null

## Method Details

generateSlug() protected method

This method is called by getValue() to generate the slug.

You may override it to customize slug generation. The default implementation calls yii\helpers\Inflector::slug() on the input strings concatenated by dashes (`-`).

protected string generateSlug ( $slugParts )
$slugParts | array | An array of strings that should be concatenated and converted to generate the slug value.
return | string | The conversion result.

generateUniqueSlug() protected method

Generates slug using configured callback or increment of iteration.

protected string generateUniqueSlug ( $baseSlug, $iteration )
$baseSlug | string | Base slug value
$iteration | integer | Iteration number
return | string | New slug value
throws | yii\base\InvalidConfigException |

getValue() protected method

Returns the value for the current attributes.

This method is called by evaluateAttributes(). Its return value will be assigned to the attributes corresponding to the triggering event.

protected mixed getValue ( $event )
$event | yii\base\Event | The event that triggers the current attribute updating.
return | mixed | The attribute value

init() public method

Initializes the object.

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

public void init ( )

isEmpty() protected method (available since version 2.0.13)

Checks if $slugPart is empty string or null.

protected boolean isEmpty ( $slugPart )
$slugPart | string | One of attributes that is used for slug generation.
return | boolean | Whether $slugPart empty or not.

isNewSlugNeeded() protected method (available since version 2.0.7)

Checks whether the new slug generation is needed This method is called by getValue() to check whether the new slug generation is needed.

You may override it to customize checking.

protected boolean isNewSlugNeeded ( )

makeUnique() protected method (available since version 2.0.7)

This method is called by getValue() when $ensureUnique is true to generate the unique slug.

Calls generateUniqueSlug() until generated slug is unique and returns it.

See also:

- getValue()
- generateUniqueSlug()

protected string makeUnique ( $slug )
$slug | string | Basic slug value
return | string | Unique slug

validateSlug() protected method

Checks if given slug value is unique.

protected boolean validateSlug ( $slug )
$slug | string | Slug value
return | boolean | Whether slug is unique.