Title: PromptBuilder::normalizePreferenceIdentifier
Published: May 20, 2026

---

# PromptBuilder::normalizePreferenceIdentifier( mixed $value, string $emptyMessage = 'Model preference identifiers cannot be empty.' ): string

## In this article

 * [Parameters](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#parameters)
 * [Return](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#return)
 * [Source](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#wp--skip-link--target)

This function’s access is marked private. This means it is not intended for use 
by plugin or theme developers, only by core. It is listed here for completeness.

Normalizes and validates a preference identifier string.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#parameters)󠁿

 `$value`mixedrequired

The value to normalize.

`$emptyMessage`stringoptional

The message for empty or invalid values.

Default:`'Model preference identifiers cannot be empty.'`

## 󠀁[Return](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#return)󠁿

 string The normalized identifier.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#source)󠁿

    ```php
    private function normalizePreferenceIdentifier($value, string $emptyMessage = 'Model preference identifiers cannot be empty.'): string
    {
        if (!is_string($value)) {
            throw new InvalidArgumentException($emptyMessage);
        }
        $trimmed = trim($value);
        if ($trimmed === '') {
            throw new InvalidArgumentException($emptyMessage);
        }
        return $trimmed;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/php-ai-client/src/builders/promptbuilder.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-includes/php-ai-client/src/Builders/PromptBuilder.php#L1265)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-includes/php-ai-client/src/Builders/PromptBuilder.php#L1265-L1275)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#related)󠁿

| Used by | Description | 
| [PromptBuilder::usingModelPreference()](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/usingmodelpreference/)`wp-includes/php-ai-client/src/Builders/PromptBuilder.php` |

Sets preferred models to evaluate in order.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wordpress-aiclient-builders-promptbuilder/normalizepreferenceidentifier/?output_format=md#changelog)󠁿

| Version | Description | 
| [0.2.0](https://developer.wordpress.org/reference/since/0.2.0/) | Introduced. |

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