如何在php SPL迭代器中跳过当前

Question

It must be a silly questions for experts but can't figure out how.

I have a csv of couple of thousands rows and some rows are empty. As I am implementing SPL Iterator it returns me the null rows as well, which breaks my array_combine .

My question is, what can I do to skip the empty rows using the Iterator.

class CSVIterator implements Iterator {

const ROW_LENGTH = 4096;
/**
 * csv file path to load 
 * @var string
 */
private $_filePointer;

/**
 * @var array
 */
private $_currentElement;

/**
 * @var integer
 */
private $_rowCounter;

/**
 * @var string
 */
private $_delimiter;

/**
 * @param string $file        path of csv file
 * @param array  $columnNames optional column headings
 * @param string $delimiter
 */
public function __construct($file, $columnNames=array(), $delimiter=',') {
    if (! file_exists($file)) {
        throw new InvalidArgumentException("The file $file cannot be read", 1);
    }
    $this->_filePointer = fopen($file, 'r');
    $this->_delimiter = $delimiter;
    $this->_columnNames = $columnNames;
}

/**
 * get column headings for array keys
 * @return void
 */
function rewind() {
    $this->_rowCounter = 0;
    rewind($this->_filePointer);
    // get array keys
    if (empty($this->_columnNames)) {
        $this->_columnNames = fgetcsv($this->_filePointer, self::ROW_LENGTH, $this->_delimiter);
    } else {
        // skip the header row
        fgetcsv($this->_filePointer, self::ROW_LENGTH, $this->_delimiter);
    }


}

/**
 * create key value pair with column headings and csv rows
 * @return array
 */
function current() {
    $this->_currentElement = 
        fgetcsv($this->_filePointer, self::ROW_LENGTH, $this->_delimiter);
    $this->_rowCounter ++;
    $keyValue = array_combine($this->_columnNames, $this->_currentElement);
    return $keyValue;
}

/**
 * @return integer
 */
function key() {
    return $this->_rowCounter;
}

/**
 * check if end of file
 * @return boolean
 */
function next() {
    return ! feof($this->_filePointer);
}

/**
 * close file if EOF
 * @return boolean
 */
function valid() {
    if (! $this->next()) {
        fclose($this->_filePointer);
        return FALSE;
    }
    return TRUE;
}

}

Answer 1

I actually figured out SPL Filter Iterator can do that for me. This is an abstract class which has an abstract accept method

public abstract bool accept ( void )

where I can specify my criteria to skip current .