* @link http://www.yiiframework.com/
* @copyright 2008-2013 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CChoiceFormat is a helper that chooses an appropriate message based on the specified number value.
* The candidate messages are given as a string in the following format:
*
* 'expr1#message1|expr2#message2|expr3#message3'
*
* where each expression should be a valid PHP expression with 'n' as the only variable.
* For example, 'n==1' and 'n%10==2 && n>10' are both valid expressions.
* The variable 'n' will take the given number value, and if an expression evaluates true,
* the corresponding message will be returned.
*
* For example, given the candidate messages 'n==1#one|n==2#two|n>2#others' and
* the number value 2, the resulting message will be 'two'.
*
* For expressions like 'n==1', we can also use a shortcut '1'. So the above example
* candidate messages can be simplified as '1#one|2#two|n>2#others'.
*
* In case the given number doesn't select any message, the last candidate message
* will be returned.
*
* The PHP expressions will be evaluated using {@link evaluate}.
*
* @author Qiang Xue
* @package system.i18n
*/
class CChoiceFormat
{
/**
* Formats a message according to the specified number value.
* @param string $messages the candidate messages in the format of 'expr1#message1|expr2#message2|expr3#message3'.
* See {@link CChoiceFormat} for more details.
* @param mixed $number the number value
* @return string the selected message
*/
public static function format($messages, $number)
{
$n=preg_match_all('/\s*([^#]*)\s*#([^\|]*)\|/',$messages.'|',$matches);
if($n===0)
return $messages;
for($i=0;$i<$n;++$i)
{
$expression=$matches[1][$i];
$message=$matches[2][$i];
if($expression===(string)(int)$expression)
{
if($expression==$number)
return $message;
}
elseif(self::evaluate(str_replace('n','$n',$expression),$number))
return $message;
}
return $message; // return the last choice
}
/**
* Evaluates a PHP expression with the given number value.
* @param string $expression the PHP expression
* @param mixed $n the number value
* @return boolean the expression result
*/
protected static function evaluate($expression,$n)
{
return @eval("return $expression;");
}
}