<?php

class Str{
	public static function truncate($str, $len, $symbols = null){
		if($str && $len){
			if(mb_strlen($str) > $len){
				$str = mb_substr($str, 0, $len, "UTF-8");
				if($symbols)
					$str .= $symbols;
			}
		}
		
		return $str;
	}
	
	public static function split($str, $len){
		if(strlen($str) > $len){
			$str = strrev($str);
			$str = str_split($str, $len);
			$arr = array();
			foreach($str as $val){
				array_unshift($arr, strrev($val));
			}
			$str = $arr;
		}
		else
			$str = array($str);
		
		return $str;
	}
	
	public static function rsplit($str, $len){
		if(strlen($str) > $len){
			$str = strrev($str);
			$str = str_split($str, $len);
			$arr = array();
			foreach($str as $val){
				$arr[] = strrev($val);
			}
			$str = $arr;
		}
		else
			$str = array($str);
		
		return $str;
	}
	
	public static function isBlank($str){
		$str = trim($str);
		
		return empty($str) && $str !== 0 && $str !== "0" ? true : false;
	}
}