public function cacheExists()
    {
        $cacheFile = $this->getCacheFile();
        if (file_exists($cacheFile) && filemtime($cacheFile) > (time()-$this->cachePeriod)) {
            return(true);
        } else {
            return(false);
        }
    }
public function cacheExists()
    {
        $cacheFile = $this->getCacheFile();
        if (file_exists($cacheFile) && filemtime($cacheFile) > (time()-$this->cachePeriod)) {
            return(true);
        } else {
            return(false);
        }
    }
public function cacheExists ( ) { $ cacheFile = $ this -> getCacheFile ( ) ; if ( file_exists ( $ cacheFile ) && filemtime ( $ cacheFile ) > ( time ( ) - $ this -> cachePeriod ) ) { return ( true ) ; } else { return ( false ) ; } }
Check whether a cache file exists and is not expired.

@return bool
Check whether a cache file exists and is not expired .