cachingiterator.inc

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<?php

class CachingIterator implements OuterIterator
{
    const CALL_TOSTRING        = 0x00000001;
    const CATCH_GET_CHILD      = 0x00000002;
    const TOSTRING_USE_KEY     = 0x00000010;
    const TOSTRING_USE_CURRENT = 0x00000020;

    private $it;
    private $current;
    private $key;
    private $valid;
    private $strValue;

    function __construct(Iterator $it, $flags = self::CALL_TOSTRING)
    {
        if ((($flags & self::CALL_TOSTRING) && ($flags & (self::TOSTRING_USE_KEY|self::TOSTRING_USE_CURRENT)))
        || ((flags & (self::CIT_TOSTRING_USE_KEY|self::CIT_TOSTRING_USE_CURRENT)) == (self::CIT_TOSTRING_USE_KEY|self::CIT_TOSTRING_USE_CURRENT)))
        {
            throw new InvalidArgumentException('Flags must contain only one of CIT_CALL_TOSTRING, CIT_TOSTRING_USE_KEY, CIT_TOSTRING_USE_CURRENT');
        }
        $this->it = $it;
        $this->flags = $flags & (0x0000FFFF);
        $this->next();
    }

    function rewind()
    {
        $this->it->rewind();
        $this->next();
    }
    
    function next()
    {
        if ($this->valid = $this->it->valid()) {
            $this->current = $this->it->current();
            $this->key = $this->it->key();
            if ($this->flags & self::CALL_TOSTRING) {
                if (is_object($this->current)) {
                    $this->strValue = $this->current->__toString();
                } else {
                    $this->strValue = (string)$this->current;
                }
            }
        } else {
            $this->current = NULL;
            $this->key = NULL;
            $this->strValue = NULL;
        }
        $this->it->next();
    }
    
    function valid()
    {
        return $this->valid;
    }

    function hasNext()
    {
        return $this->it->valid();
    }
    
    function current()
    {
        return $this->current;
    }

    function key()
    {
        return $this->key;
    }

    function __call($func, $params)
    {
        return call_user_func_array(array($this->it, $func), $params);
    }
    
    function __toString()
    {
        if ($this->flags & self::TOSTRING_USE_KEY)
        {
            return $this->key;
        }
        else if ($this->flags & self::TOSTRING_USE_CURRENT)
        {
            return $this->current;
        }
        if (!$this->flags & self::CALL_TOSTRING)
        {
            throw new exception('CachingIterator does not fetch string value (see CachingIterator::__construct)');
        }
        return $this->strValue;
    }
    
    function getInnerIterator()
    {
        return $this->it;
    }
}

?>