<?php
/**
 * @defgroup form_validation Form Validation
 */

/**
 * @file classes/form/validation/FormValidator.inc.php
 *
 * Copyright (c) 2014-2019 Simon Fraser University
 * Copyright (c) 2000-2019 John Willinsky
 * Distributed under the GNU GPL v2. For full terms see the file docs/COPYING.
 *
 * @class FormValidator
 * @ingroup form_validation
 *
 * @brief Class to represent a form validation check.
 */

// The two allowed states for the type field
define('FORM_VALIDATOR_OPTIONAL_VALUE', 'optional');
define('FORM_VALIDATOR_REQUIRED_VALUE', 'required');

class FormValidator {

	/** @var Form The Form associated with the check */
	var $_form;

	/** @var string The name of the field */
	var $_field;

	/** @var string The type of check ("required" or "optional") */
	var $_type;

	/** @var string The error message associated with a validation failure */
	var $_message;

	/** @var Validator The validator used to validate the field */
	var $_validator;

	/**
	 * Constructor.
	 * @param $form Form the associated form
	 * @param $field string the name of the associated field
	 * @param $type string the type of check, either "required" or "optional"
	 * @param $message string the error message for validation failures (i18n key)
	 * @param $validator Validator the validator used to validate this form field (optional)
	 */
	function __construct(&$form, $field, $type, $message, $validator = null) {
		$this->_form =& $form;
		$this->_field = $field;
		$this->_type = $type;
		$this->_message = $message;
		$this->_validator =& $validator;

		$form->cssValidation[$field] = array();
		if ($type == FORM_VALIDATOR_REQUIRED_VALUE) {
			array_push($form->cssValidation[$field], 'required');
		}
	}


	//
	// Setters and Getters
	//
	/**
	 * Get the field associated with the check.
	 * @return string
	 */
	function getField() {
		return $this->_field;
	}

	/**
	 * Get the error message associated with a failed validation check.
	 * @return string
	 */
	function getMessage() {
		return __($this->_message);
	}

	/**
	 * Get the form associated with the check
	 * @return Form
	 */
	function &getForm() {
		return $this->_form;
	}

	/**
	 * Get the validator associated with the check
	 * @return Validator
	 */
	function &getValidator() {
		return $this->_validator;
	}

	/**
	 * Get the type of the validated field ('optional' or 'required')
	 * @return string
	 */
	function getType() {
		return $this->_type;
	}


	//
	// Public methods
	//
	/**
	 * Check if field value is valid.
	 * Default check is that field is either optional or not empty.
	 * @return boolean
	 */
	function isValid() {
		if ($this->isEmptyAndOptional()) return true;

		$validator =& $this->getValidator();
		if (is_null($validator)) {
			// Default check: field must not be empty.
			$fieldValue = $this->getFieldValue();
			if (is_scalar($fieldValue)) {
				return $fieldValue !== '';
			} else {
				return $fieldValue !== array();
			}
		} else {
			// Delegate to the validator for the field value check.
			return $validator->isValid($this->getFieldValue());
		}
	}

	//
	// Protected helper methods
	//
	/**
	 * Get field value
	 * @return mixed
	 */
	function getFieldValue() {
		$form =& $this->getForm();
		$fieldValue = $form->getData($this->getField());
		if (is_null($fieldValue) || is_scalar($fieldValue)) $fieldValue = trim((string)$fieldValue);
		return $fieldValue;
	}

	/**
	 * Check if field value is empty and optional.
	 * @return boolean
	 */
	function isEmptyAndOptional() {
		if ($this->getType() != FORM_VALIDATOR_OPTIONAL_VALUE) return false;

		$fieldValue = $this->getFieldValue();
		if (is_scalar($fieldValue)) {
			return $fieldValue == '';
		} else {
			return empty($fieldValue);
		}
	}
}


