转换连续空格，回车和tab到单个空格或是指定字符串。
如果你希望转换模板文字内的空格，使用内置的
{strip} 函数。
Example 5.19. strip
<?php
$smarty->assign('articleTitle', "Grandmother of\neight makes\t hole in one.");
$smarty->display('index.tpl');
?>
模板：
{$articleTitle}
{$articleTitle|strip}
{$articleTitle|strip:' '}
输出：
Grandmother of eight makes hole in one. Grandmother of eight makes hole in one. Grandmother of eight makes hole in one.