www.mikescher.com/framework/validators/CStringValidator.php

<?php
/**
 * CStringValidator class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright 2008-2013 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CStringValidator validates that the attribute value is of certain length.
 *
 * Note, this validator should only be used with string-typed attributes.
 *
 * In addition to the {@link message} property for setting a custom error message,
 * CStringValidator has a couple custom error messages you can set that correspond to different
 * validation scenarios. For defining a custom message when the string is too short,
 * you may use the {@link tooShort} property. Similarly with {@link tooLong}. The messages may contain
 * placeholders that will be replaced with the actual content. In addition to the "{attribute}"
 * placeholder, recognized by all validators (see {@link CValidator}), CStringValidator allows for the following
 * placeholders to be specified:
 * <ul>
 * <li>{min}: when using {@link tooShort}, replaced with minimum length, {@link min}, if set.</li>
 * <li>{max}: when using {@link tooLong}, replaced with the maximum length, {@link max}, if set.</li>
 * <li>{length}: when using {@link message}, replaced with the exact required length, {@link is}, if set.</li>
 * </ul>
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.validators
 * @since 1.0
 */
class CStringValidator extends CValidator
{
	/**
	 * @var integer maximum length. Defaults to null, meaning no maximum limit.
	 */
	public $max;
	/**
	 * @var integer minimum length. Defaults to null, meaning no minimum limit.
	 */
	public $min;
	/**
	 * @var integer exact length. Defaults to null, meaning no exact length limit.
	 */
	public $is;
	/**
	 * @var string user-defined error message used when the value is too short.
	 */
	public $tooShort;
	/**
	 * @var string user-defined error message used when the value is too long.
	 */
	public $tooLong;
	/**
	 * @var boolean whether the attribute value can be null or empty. Defaults to true,
	 * meaning that if the attribute is empty, it is considered valid.
	 */
	public $allowEmpty=true;
	/**
	 * @var string the encoding of the string value to be validated (e.g. 'UTF-8').
	 * This property is used only when mbstring PHP extension is enabled.
	 * The value of this property will be used as the 2nd parameter of the
	 * mb_strlen() function. If this property is not set, the application charset
	 * will be used.
	 * If this property is set false, then strlen() will be used even if mbstring is enabled.
	 * @since 1.1.1
	 */
	public $encoding;

	/**
	 * Validates the attribute of the object.
	 * If there is any error, the error message is added to the object.
	 * @param CModel $object the object being validated
	 * @param string $attribute the attribute being validated
	 */
	protected function validateAttribute($object,$attribute)
	{
		$value=$object->$attribute;
		if($this->allowEmpty && $this->isEmpty($value))
			return;

		if(is_array($value))
		{
			// https://github.com/yiisoft/yii/issues/1955
			$this->addError($object,$attribute,Yii::t('yii','{attribute} is invalid.'));
			return;
		}

		if(function_exists('mb_strlen') && $this->encoding!==false)
			$length=mb_strlen($value, $this->encoding ? $this->encoding : Yii::app()->charset);
		else
			$length=strlen($value);

		if($this->min!==null && $length<$this->min)
		{
			$message=$this->tooShort!==null?$this->tooShort:Yii::t('yii','{attribute} is too short (minimum is {min} characters).');
			$this->addError($object,$attribute,$message,array('{min}'=>$this->min));
		}
		if($this->max!==null && $length>$this->max)
		{
			$message=$this->tooLong!==null?$this->tooLong:Yii::t('yii','{attribute} is too long (maximum is {max} characters).');
			$this->addError($object,$attribute,$message,array('{max}'=>$this->max));
		}
		if($this->is!==null && $length!==$this->is)
		{
			$message=$this->message!==null?$this->message:Yii::t('yii','{attribute} is of the wrong length (should be {length} characters).');
			$this->addError($object,$attribute,$message,array('{length}'=>$this->is));
		}
	}

	/**
	 * Returns the JavaScript needed for performing client-side validation.
	 * @param CModel $object the data object being validated
	 * @param string $attribute the name of the attribute to be validated.
	 * @return string the client-side validation script.
	 * @see CActiveForm::enableClientValidation
	 * @since 1.1.7
	 */
	public function clientValidateAttribute($object,$attribute)
	{
		$label=$object->getAttributeLabel($attribute);

		if(($message=$this->message)===null)
			$message=Yii::t('yii','{attribute} is of the wrong length (should be {length} characters).');
		$message=strtr($message, array(
			'{attribute}'=>$label,
			'{length}'=>$this->is,
		));

		if(($tooShort=$this->tooShort)===null)
			$tooShort=Yii::t('yii','{attribute} is too short (minimum is {min} characters).');
		$tooShort=strtr($tooShort, array(
			'{attribute}'=>$label,
			'{min}'=>$this->min,
		));

		if(($tooLong=$this->tooLong)===null)
			$tooLong=Yii::t('yii','{attribute} is too long (maximum is {max} characters).');
		$tooLong=strtr($tooLong, array(
			'{attribute}'=>$label,
			'{max}'=>$this->max,
		));

		$js='';
		if($this->min!==null)
		{
			$js.="
if(value.length<{$this->min}) {
	messages.push(".CJSON::encode($tooShort).");
}
";
		}
		if($this->max!==null)
		{
			$js.="
if(value.length>{$this->max}) {
	messages.push(".CJSON::encode($tooLong).");
}
";
		}
		if($this->is!==null)
		{
			$js.="
if(value.length!={$this->is}) {
	messages.push(".CJSON::encode($message).");
}
";
		}

		if($this->allowEmpty)
		{
			$js="
if(jQuery.trim(value)!='') {
	$js
}
";
		}

		return $js;
	}
}