yii2-bootstrap/framework/assets/yii.validation.js

/**
 * Yii validation module.
 *
 * This is the JavaScript widget used by the yii\widgets\ActiveForm widget.
 *
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */

yii.validation = (function ($) {
	var isEmpty = function (value, trim) {
		return value === null || value === undefined || value == []
			|| value === '' || trim && $.trim(value) === '';
	};

	return {
		required: function (value, messages, options) {
			var valid  = false;
			if (options.requiredValue === undefined) {
				if (options.strict && value !== undefined || !options.strict && !isEmpty(value, true)) {
					valid = true;
				}
			} else if (!options.strict && value == options.requiredValue || options.strict && value === options.requiredValue) {
				valid = true;
			}

			valid || messages.push(options.message);
		},

		boolean: function (value, messages, options) {
			if (options.skipOnEmpty && isEmpty(value)) {
				return;
			}
			var valid = !options.strict && (value == options.trueValue || value == options.falseValue)
				|| options.strict && (value === options.trueValue || value === options.falseValue);

			valid || messages.push(options.message);
		}
	};
})(jQuery);