/**
 * @module FormValidator
 * Form validation with support for native HTML5 validation and error summaries.
 * Provides automatic validation on submit with customizable behavior.
 *
 * @example
 * // Basic usage with submit callback
 * const form = document.querySelector('form');
 * const validator = new FormValidator(form, {
 *     submitCallback: () => saveData()
 * });
 *
 * @example
 * // With auto-validation on input
 * const validator = new FormValidator(form, {
 *     autoValidate: true,
 *     useSummary: true
 * });
 */
/**
 * Configuration options for FormValidator.
 */
export interface ValidatorOptions {
    /** Validate on every input event, not just submit */
    autoValidate?: boolean;
    /** Show errors in a summary element instead of browser tooltips */
    useSummary?: boolean;
    /** Custom validation function called before native validation */
    customChecks?: (form: HTMLFormElement) => void;
    /** Always prevent default form submission */
    preventDefault?: boolean;
    /** Prevent default on validation failure (default: true) */
    preventDefaultOnFailed?: boolean;
    /** Callback invoked when form passes validation */
    submitCallback?: () => void;
}
/**
 * Form validation helper that integrates with HTML5 validation.
 * Supports error summaries, auto-validation, and custom submit handling.
 *
 * @example
 * // Prevent submission and handle manually
 * class MyComponent extends HTMLElement {
 *     private validator: FormValidator;
 *
 *     connectedCallback() {
 *         const form = this.querySelector('form');
 *         this.validator = new FormValidator(form, {
 *             submitCallback: () => this.handleSubmit()
 *         });
 *     }
 *
 *     private async handleSubmit() {
 *         const data = readData(this.form);
 *         await fetch('/api/save', { method: 'POST', body: JSON.stringify(data) });
 *     }
 * }
 *
 * @example
 * // With error summary display
 * const validator = new FormValidator(form, {
 *     useSummary: true,
 *     autoValidate: true
 * });
 */
export declare class FormValidator {
    private form;
    private options?;
    private errorSummary;
    constructor(form: HTMLFormElement, options?: ValidatorOptions);
    /**
     * Validates all form fields.
     * Uses native HTML5 validation and optionally displays an error summary.
     *
     * @returns true if form is valid, false otherwise
     */
    validateForm(): boolean;
    /**
     * Displays a list of error messages in the summary element.
     *
     * @param messages - Array of error messages to display
     */
    displayErrorSummary(messages: string[]): void;
    private createErrorSummary;
    /**
     * Adds a single error to the summary display.
     *
     * @param fieldName - The name of the field with the error
     * @param message - The error message
     */
    addErrorToSummary(fieldName: string, message: string): void;
    /**
     * Clears all errors from the summary display.
     */
    clearErrorSummary(): void;
    private focusFirstErrorElement;
    /**
     * Finds a form element relative to the given element.
     * Searches parent first, then direct children.
     *
     * @param element - The element to search from
     * @returns The found form element
     * @throws Error if no form is found
     *
     * @example
     * class MyComponent extends HTMLElement {
     *     connectedCallback() {
     *         const form = FormValidator.FindForm(this);
     *         new FormValidator(form);
     *     }
     * }
     */
    static FindForm(element: HTMLElement): HTMLFormElement;
}