title('My Prompt') * ->argument('input', 'Input text', true) * ->handler(function(array $args): array { * return ['messages' => [...]]; * }); * * // Array configuration (WordPress-style) * $prompt = McpPrompt::fromArray([ * 'name' => 'my-prompt', * 'title' => 'My Prompt', * 'arguments' => [['name' => 'input', 'description' => 'Input text', 'required' => true]], * 'handler' => function(array $args): array { return [...]; }, * ]); * ``` * * This class remains functional for backward compatibility but will be * removed in a future major version. * * @see McpPrompt For the preferred prompt creation API. */ abstract class McpPromptBuilder implements McpPromptBuilderInterface { /** * The prompt name (unique identifier). * * @var string */ protected string $name = ''; /** * The prompt title (human-readable display name). * * @var string|null */ protected ?string $title = null; /** * The prompt description. * * @var string|null */ protected ?string $description = null; /** * The prompt arguments. * * @var list */ protected array $arguments = array(); /** * The prompt icons for UI display. * * @since 0.5.0 * * @var list, theme?: string}>|null */ protected ?array $icons = null; /** * Additional metadata passed through to MCP clients. * * Use this to attach purpose-specific metadata that MCP clients can consume. * Keys are passed through unchanged. * * @since 0.5.0 * * @var array */ protected array $meta = array(); /** * Constructor - automatically configures the prompt. * * Configuration happens exactly once during construction, ensuring * idempotent behavior. Subclasses should NOT override this constructor; * instead, implement the configure() method. * * @since 0.5.0 */ final public function __construct() { $this->configure(); } /** * Configure the prompt properties. * * Subclasses must implement this method to set the name, title, * description, and arguments for the prompt. This method is called * exactly once during construction. * * @return void */ abstract protected function configure(): void; /** * Build and return the Prompt DTO instance. * * This method converts the configured state into an MCP Prompt DTO. * Safe to call multiple times - always returns a fresh DTO based on * the current (immutable after construction) state. * * @return \WP\McpSchema\Server\Prompts\DTO\Prompt The built prompt DTO. */ public function build(): PromptDto { $argument_dtos = null; if ( ! empty( $this->arguments ) ) { $argument_dtos = array_map( static function ( array $arg ): PromptArgument { return PromptArgument::fromArray( array( 'name' => $arg['name'], 'title' => $arg['title'] ?? null, 'description' => $arg['description'] ?? null, 'required' => $arg['required'] ?? null, ) ); }, $this->arguments ); } // Validate and prepare icons if set. $valid_icons = null; if ( ! empty( $this->icons ) ) { $icons_result = McpValidator::validate_icons_array( $this->icons ); if ( ! empty( $icons_result['valid'] ) ) { $valid_icons = $icons_result['valid']; } } $prompt_data = array( 'name' => $this->name, 'title' => $this->title, 'description' => $this->description, 'arguments' => $argument_dtos, ); if ( ! empty( $this->meta ) ) { $prompt_data['_meta'] = $this->meta; } // Only include icons if valid ones exist. if ( null !== $valid_icons ) { $prompt_data['icons'] = $valid_icons; } return PromptDto::fromArray( $prompt_data ); } /** * Get the unique name for this prompt. * * @return string The prompt name. */ public function get_name(): string { return $this->name; } /** * Get the prompt title. * * @return string|null The prompt title. */ public function get_title(): ?string { return $this->title; } /** * Get the prompt description. * * @return string|null The prompt description. */ public function get_description(): ?string { return $this->description; } /** * Get the prompt arguments. * * @return list The prompt arguments. */ public function get_arguments(): array { return $this->arguments; } /** * Get the prompt icons. * * @return list, theme?: string}> The prompt icons. * @since 0.5.0 * */ public function get_icons(): array { return $this->icons ?? array(); } /** * Set the prompt icons for UI display. * * Icons are validated during build() using McpValidator::validate_icons_array(). * Invalid icons are filtered out with warnings (graceful degradation). * * Per MCP 2025-11-25: * - MUST support: image/png, image/jpeg, image/jpg * - SHOULD support: image/svg+xml, image/webp * * @param list, theme?: string}> $icons Array of icon definitions. * * @return self * @since 0.5.0 * */ protected function set_icons( array $icons ): self { $this->icons = $icons; return $this; } /** * Get the additional metadata. * * @return array The additional metadata. * @since 0.5.0 * */ public function get_meta(): array { return $this->meta; } /** * Set additional metadata. * * This metadata is passed through to MCP clients unchanged. * * @param array $meta Additional metadata key-value pairs. * * @return self * @since 0.5.0 * */ protected function set_meta( array $meta ): self { $this->meta = $meta; return $this; } /** * Handle the prompt execution when called. * * Subclasses must implement this method to handle the prompt logic. * * @param array $arguments The arguments passed to the prompt. * * @return array The prompt response. */ abstract public function handle( array $arguments ): array; /** * Check if the current user has permission to execute this prompt. * * Default implementation allows all executions. Override this method * to implement custom permission logic. * * @param array $arguments The arguments passed to the prompt. * * @return bool True if execution is allowed, false otherwise. */ public function has_permission( array $arguments ): bool { // Default: allow all executions // Override this method to implement custom permission logic return true; } /** * Helper method to add an argument to the prompt. * * @param string $name The argument name. * @param string|null $description Optional argument description. * @param bool $required Whether the argument is required. * * @return self */ protected function add_argument( string $name, ?string $description = null, bool $required = false ): self { $this->arguments[] = $this->create_argument( $name, $description, $required ); return $this; } /** * Helper method to create an argument definition. * * @param string $name The argument name. * @param string|null $description Optional argument description. * @param bool $required Whether the argument is required. * * @return array{name: string, description?: string, required?: true} The argument definition. */ protected function create_argument( string $name, ?string $description = null, bool $required = false ): array { $argument = array( 'name' => $name, ); if ( null !== $description ) { $argument['description'] = $description; } if ( $required ) { $argument['required'] = true; } return $argument; } }