CachingIterator Class Reference

Inheritance diagram for CachingIterator:

Collaboration diagram for CachingIterator:

Public Member Functions
	__call ($func, $params)
	__construct (Iterator $it, $flags=self::CALL_TOSTRING)
	__toString ()
	current ()
	getInnerIterator ()
	hasNext ()
	key ()
	next ()
	rewind ()
	valid ()

Public Attributes
const	CALL_TOSTRING = 0x00000001
const	CATCH_GET_CHILD = 0x00000002
const	TOSTRING_USE_CURRENT = 0x00000020
const	TOSTRING_USE_KEY = 0x00000010

Private Attributes
	$current
	$it
	$key
	$strValue
	$valid

Detailed Description

Cached iteration over another Iterator.

Author

Marcus Boerger

Version

1.2

Since

PHP 5.0

This iterator wrapper does a one ahead iteration. This way it knows whether the inner iterator has one more element.

Note

If you want to convert the elements into strings and the inner Iterator is an internal Iterator then you need to provide the flag CALL_TOSTRING to do the conversion when the actual element is being fetched. Otherwise the conversion would happen with the already changed iterator. If you do not need this then it you should omit this flag because it costs unnecessary work and time.

Definition at line 28 of file cachingiterator.inc.

Constructor & Destructor Documentation

CachingIterator::__construct	(	Iterator	$it,
			$flags = self::CALL_TOSTRING
	)

Construct from another iterator.

Parameters

it	Iterator to cache
flags	Bitmask: CALL_TOSTRING (whether to call __toString() for every element)

Definition at line 47 of file cachingiterator.inc.

References $it, and next().

    {
        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();
    }

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Member Function Documentation

CachingIterator::__call	(		$func,
			$params
	)

Aggregate the inner iterator.

Parameters

func	Name of method to invoke
params	Array of parameters to pass to method

Definition at line 122 of file cachingiterator.inc.

    {
        return call_user_func_array(array($this->it, $func), $params);
    }

CachingIterator::__toString

(

)

Returns

the string represenatation that was generated for the current element

Exceptions

exception

when CALL_TOSTRING was not specified in constructor

Definition at line 131 of file cachingiterator.inc.

References $current, $key, and $strValue.

    {
        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;
    }

CachingIterator::current

(

)

Returns

the current element

Implements Iterator.

Definition at line 105 of file cachingiterator.inc.

References $current.

Referenced by next().

    {
        return $this->current;
    }

CachingIterator::getInnerIterator

(

)

Returns

The inner iterator

Implements OuterIterator.

Definition at line 151 of file cachingiterator.inc.

References $it.

    {
        return $this->it;
    }

CachingIterator::hasNext

(

)

Returns

whether there is one more element

Definition at line 98 of file cachingiterator.inc.

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

CachingIterator::key

(

)

Returns

the current key

Implements Iterator.

Definition at line 112 of file cachingiterator.inc.

References $key.

Referenced by next().

    {
        return $this->key;
    }

CachingIterator::next

(

)

Forward to the next element.

Implements Iterator.

Definition at line 69 of file cachingiterator.inc.

References current(), key(), and valid().

Referenced by __construct(), and rewind().

    {
        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();
    }

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CachingIterator::rewind

(

)

Rewind the Iterator.

Implements Iterator.

Definition at line 61 of file cachingiterator.inc.

References next().

    {
        $this->it->rewind();
        $this->next();
    }

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CachingIterator::valid

(

)

Returns

whether the iterator is valid

Implements Iterator.

Definition at line 91 of file cachingiterator.inc.

References $valid.

Referenced by next().

    {
        return $this->valid;
    }

Member Data Documentation

CachingIterator::$current

private

Definition at line 36 of file cachingiterator.inc.

Referenced by __toString(), and current().

CachingIterator::$it

private

Definition at line 35 of file cachingiterator.inc.

Referenced by __construct(), and getInnerIterator().

CachingIterator::$key

private

Definition at line 37 of file cachingiterator.inc.

Referenced by __toString(), and key().

CachingIterator::$strValue

private

Definition at line 39 of file cachingiterator.inc.

Referenced by __toString().

CachingIterator::$valid

private

Definition at line 38 of file cachingiterator.inc.

Referenced by valid().

const CachingIterator::CALL_TOSTRING = 0x00000001

Definition at line 30 of file cachingiterator.inc.

Referenced by DirectoryGraphIterator\__construct(), and DirectoryTreeIterator\__construct().

const CachingIterator::CATCH_GET_CHILD = 0x00000002

Definition at line 31 of file cachingiterator.inc.

Referenced by DirectoryGraphIterator\__construct(), and DirectoryTreeIterator\__construct().

const CachingIterator::TOSTRING_USE_CURRENT = 0x00000020

Definition at line 33 of file cachingiterator.inc.

const CachingIterator::TOSTRING_USE_KEY = 0x00000010

Definition at line 32 of file cachingiterator.inc.

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The documentation for this class was generated from the following file:

• cachingiterator.inc