Fluent builder for constructing AI prompts, returning WP_Error on failure.
Description
This class provides a fluent interface for building prompts with various content types and model configurations. It wraps the PHP AI Client SDK’s PromptBuilder and adds WordPress-specific behavior including WP_Error handling instead of exceptions, snake_case method naming, and integration with the Abilities API.
Only the generating methods will return a WP_Error, to not break the fluent interface. As soon as any exception is caught in a chain of method calls, the returned instance will be in an error state, and all subsequent method calls will be no-ops that just return the same error state instance. Only when a generating method is called, the WP_Error will be returned.
Methods
| Name | Description |
|---|---|
| WP_AI_Client_Prompt_Builder::__call | Magic method to proxy snake_case method calls to their PHP AI Client camelCase counterparts. |
| WP_AI_Client_Prompt_Builder::__construct | Constructor. |
| WP_AI_Client_Prompt_Builder::exception_to_wp_error | Converts an exception into a WP_Error with a structured error code and message. |
| WP_AI_Client_Prompt_Builder::get_builder_callable | Retrieves a callable for a given PHP AI Client SDK prompt builder method name. |
| WP_AI_Client_Prompt_Builder::is_generating_method | Checks if a method name is a generating method (generate_*, convert_text_to_speech*). |
| WP_AI_Client_Prompt_Builder::is_support_check_method | Checks if a method name is a support check method (is_supported*). |
| WP_AI_Client_Prompt_Builder::snake_to_camel_case | Converts snake_case to camelCase. |
| WP_AI_Client_Prompt_Builder::using_abilities | Registers WordPress abilities as function declarations for the AI model. |
Source
class WP_AI_Client_Prompt_Builder {
/**
* Wrapped prompt builder instance from the PHP AI Client SDK.
*
* @since 7.0.0
* @var PromptBuilder
*/
private PromptBuilder $builder;
/**
* WordPress error instance, if any error occurred during method calls.
*
* @since 7.0.0
* @var WP_Error|null
*/
private ?WP_Error $error = null;
/**
* List of methods that generate a result from the prompt.
*
* Structured as a map for faster lookups.
*
* @since 7.0.0
* @var array<string, bool>
*/
private static array $generating_methods = array(
'generate_result' => true,
'generate_text_result' => true,
'generate_image_result' => true,
'generate_speech_result' => true,
'convert_text_to_speech_result' => true,
'generate_video_result' => true,
'generate_text' => true,
'generate_texts' => true,
'generate_image' => true,
'generate_images' => true,
'convert_text_to_speech' => true,
'convert_text_to_speeches' => true,
'generate_speech' => true,
'generate_speeches' => true,
'generate_video' => true,
'generate_videos' => true,
);
/**
* List of methods that check whether the prompt is supported.
*
* Structured as a map for faster lookups.
*
* @since 7.0.0
* @var array<string, bool>
*/
private static array $support_check_methods = array(
'is_supported' => true,
'is_supported_for_text_generation' => true,
'is_supported_for_image_generation' => true,
'is_supported_for_text_to_speech_conversion' => true,
'is_supported_for_video_generation' => true,
'is_supported_for_speech_generation' => true,
'is_supported_for_music_generation' => true,
'is_supported_for_embedding_generation' => true,
);
/**
* Constructor.
*
* @since 7.0.0
*
* @param ProviderRegistry $registry The provider registry for finding suitable models.
* @param Prompt $prompt Optional. Initial prompt content.
* A string for simple text prompts,
* a MessagePart or Message object for
* structured content, an array for a
* message array shape, or a list of
* parts or messages for multi-turn
* conversations. Default null.
*/
public function __construct( ProviderRegistry $registry, $prompt = null ) {
try {
$this->builder = new PromptBuilder( $registry, $prompt, AiClient::getEventDispatcher() );
} catch ( Exception $e ) {
$this->builder = new PromptBuilder( $registry, null, AiClient::getEventDispatcher() );
$this->error = $this->exception_to_wp_error( $e );
}
$default_timeout = 30.0;
/**
* Filters the default request timeout in seconds for AI Client HTTP requests.
*
* @since 7.0.0
*
* @param float $default_timeout The default timeout in seconds.
*/
$filtered_default_timeout = apply_filters( 'wp_ai_client_default_request_timeout', $default_timeout );
if ( is_numeric( $filtered_default_timeout ) && (float) $filtered_default_timeout >= 0.0 ) {
$default_timeout = (float) $filtered_default_timeout;
} else {
_doing_it_wrong(
__METHOD__,
sprintf(
/* translators: %s: wp_ai_client_default_request_timeout */
__( 'The %s filter must return a non-negative number.' ),
'<code>wp_ai_client_default_request_timeout</code>'
),
'7.0.0'
);
}
$this->builder->usingRequestOptions(
RequestOptions::fromArray(
array(
RequestOptions::KEY_TIMEOUT => $default_timeout,
)
)
);
}
/**
* Registers WordPress abilities as function declarations for the AI model.
*
* Converts each WP_Ability to a FunctionDeclaration using the wpab__ prefix
* naming convention and passes them to the underlying prompt builder.
*
* @since 7.0.0
*
* @param WP_Ability|string ...$abilities The abilities to register, either as WP_Ability objects or ability name strings.
* @return self The current instance for method chaining.
*/
public function using_abilities( ...$abilities ): self {
$declarations = array();
foreach ( $abilities as $ability ) {
if ( is_string( $ability ) ) {
$ability_name = $ability;
$ability = wp_get_ability( $ability );
if ( ! $ability ) {
_doing_it_wrong(
__METHOD__,
sprintf(
/* translators: %s: string value of the ability name. */
__( 'The ability %s was not found.' ),
'<code>' . esc_html( $ability_name ) . '</code>'
),
'7.0.0'
);
continue;
}
}
// This is only here as a sanity check, the method signature should ensure this already.
if ( ! $ability instanceof WP_Ability ) {
continue;
}
$function_name = WP_AI_Client_Ability_Function_Resolver::ability_name_to_function_name( $ability->get_name() );
$input_schema = $ability->get_input_schema();
$declarations[] = new FunctionDeclaration(
$function_name,
$ability->get_description(),
! empty( $input_schema ) ? $input_schema : null
);
}
if ( ! empty( $declarations ) ) {
return $this->using_function_declarations( ...$declarations );
}
return $this;
}
/**
* Magic method to proxy snake_case method calls to their PHP AI Client camelCase counterparts.
*
* This allows WordPress developers to use snake_case naming conventions. It catches
* any exceptions thrown, stores them, and returns a WP_Error when a terminate method
* is called.
*
* @since 7.0.0
*
* @param string $name The method name in snake_case.
* @param array<int, mixed> $arguments The method arguments.
* @return mixed The result of the method call.
*/
public function __call( string $name, array $arguments ) {
/*
* If an error occurred in a previous method call, either return the error for terminate methods,
* or return the same instance for other methods to maintain the fluent interface.
*/
if ( null !== $this->error ) {
if ( self::is_generating_method( $name ) ) {
return $this->error;
}
if ( self::is_support_check_method( $name ) ) {
return false;
}
return $this;
}
// Check if the prompt should be prevented for is_supported* and generate_*/convert_text_to_speech* methods.
if ( self::is_support_check_method( $name ) || self::is_generating_method( $name ) ) {
// If AI is not supported, then there's no need to apply the filter as the prompt will be prevented anyway.
$is_ai_disabled = ! wp_supports_ai();
$prevent = $is_ai_disabled;
if ( ! $prevent ) {
/**
* Filters whether to prevent the prompt from being executed.
*
* @since 7.0.0
*
* @param bool $prevent Whether to prevent the prompt. Default false.
* @param WP_AI_Client_Prompt_Builder $builder A clone of the prompt builder instance (read-only).
*/
$prevent = (bool) apply_filters( 'wp_ai_client_prevent_prompt', false, clone $this );
}
if ( $prevent ) {
// For is_supported* methods, return false.
if ( self::is_support_check_method( $name ) ) {
return false;
}
$error_message = $is_ai_disabled
? __( 'AI features are not supported in this environment.' )
: __( 'Prompt execution was prevented by a filter.' );
// For generate_* and convert_text_to_speech* methods, create a WP_Error.
$this->error = new WP_Error(
'prompt_prevented',
$error_message,
array(
'status' => 503,
)
);
if ( self::is_generating_method( $name ) ) {
return $this->error;
}
return $this;
}
}
try {
$callable = $this->get_builder_callable( $name );
$result = $callable( ...$arguments );
// If the result is a PromptBuilder, return the current instance to allow method chaining.
if ( $result instanceof PromptBuilder ) {
return $this;
}
return $result;
} catch ( Exception $e ) {
$this->error = $this->exception_to_wp_error( $e );
if ( self::is_generating_method( $name ) ) {
return $this->error;
}
return $this;
}
}
/**
* Converts an exception into a WP_Error with a structured error code and message.
*
* This method maps different exception types to specific WP_Error codes and HTTP status codes.
* The presence of the status codes means these WP_Error objects can be easily used in REST API responses
* or other contexts where HTTP semantics are relevant.
*
* @since 7.0.0
*
* @param Exception $e The exception to convert.
* @return WP_Error The resulting WP_Error object.
*/
private function exception_to_wp_error( Exception $e ): WP_Error {
if ( $e instanceof NetworkException ) {
$error_code = 'prompt_network_error';
$status_code = 503;
} elseif ( $e instanceof ClientException ) {
// `ClientException` uses HTTP status codes as exception codes, so we can rely on them.
$error_code = 'prompt_client_error';
$status_code = $e->getCode() ? $e->getCode() : 400;
} elseif ( $e instanceof ServerException ) {
// `ServerException` uses HTTP status codes as exception codes, so we can rely on them.
$error_code = 'prompt_upstream_server_error';
$status_code = $e->getCode() ? $e->getCode() : 500;
} elseif ( $e instanceof TokenLimitReachedException ) {
$error_code = 'prompt_token_limit_reached';
$status_code = 400;
} elseif ( $e instanceof InvalidArgumentException ) {
$error_code = 'prompt_invalid_argument';
$status_code = 400;
} else {
$error_code = 'prompt_builder_error';
$status_code = 500;
}
return new WP_Error(
$error_code,
$e->getMessage(),
array(
'status' => $status_code,
'exception_class' => get_class( $e ),
)
);
}
/**
* Checks if a method name is a support check method (is_supported*).
*
* @since 7.0.0
*
* @param string $name The method name.
* @return bool True if the method is a support check method, false otherwise.
*/
private static function is_support_check_method( string $name ): bool {
return isset( self::$support_check_methods[ $name ] );
}
/**
* Checks if a method name is a generating method (generate_*, convert_text_to_speech*).
*
* @since 7.0.0
*
* @param string $name The method name.
* @return bool True if the method is a generating method, false otherwise.
*/
private static function is_generating_method( string $name ): bool {
return isset( self::$generating_methods[ $name ] );
}
/**
* Retrieves a callable for a given PHP AI Client SDK prompt builder method name.
*
* @since 7.0.0
*
* @param string $name The method name in snake_case.
* @return callable The callable for the specified method.
*
* @throws BadMethodCallException If the method does not exist.
*/
protected function get_builder_callable( string $name ): callable {
$camel_case_name = $this->snake_to_camel_case( $name );
$method = array( $this->builder, $camel_case_name );
if ( ! is_callable( $method ) ) {
throw new BadMethodCallException(
sprintf(
/* translators: 1: Method name. 2: Class name. */
__( 'Method %1$s does not exist on %2$s.' ),
$name, // phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped
get_class( $this->builder ) // phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped
)
);
}
return $method;
}
/**
* Converts snake_case to camelCase.
*
* @since 7.0.0
*
* @param string $snake_case The snake_case string.
* @return string The camelCase string.
*/
private function snake_to_camel_case( string $snake_case ): string {
$parts = explode( '_', $snake_case );
$camel_case = $parts[0];
$parts_count = count( $parts );
for ( $i = 1; $i < $parts_count; $i++ ) {
$camel_case .= ucfirst( $parts[ $i ] );
}
return $camel_case;
}
}
Changelog
| Version | Description |
|---|---|
| 7.0.0 | Introduced. |
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