[TYPO3-dev] [TYPO3-ect] PHP5 and SPL

[Rainer Kuhn]

Elmar Hinz wrote:
> One of the most impressing and usefull parts that found their way into
> PHP5 is SPL. So that we can base our work on it. SPL is the akronym
> for Standard PHP Library and currently deals with arrays, objects and
> iterators. [3]
> 
> What does SPL do? To abstract it: It defines and implements two or
> three important interfaces:
> 
> Iterator: [4]
> 
>  	current ()
>  	key ()
>  	next ()
>  	rewind ()
>  	valid ()
> 
> ArrayAccess: [5][8]
> 
>  	offsetExists ($offset)
>  	offsetGet ($offset)
>  	offsetSet ($offset, $value)
>  	offsetUnset ($offset)
>         ( append($value) )
> 
> If your object implements Iterator you can iterate it in foreach in
> PHP5, just like a usual array.
> 
> foreach($myObject as $key => $value){
> 	do something ...
> }

There's one more very interesting alternative to iterate an object in
SPL: the IteratorAggregate Interface from the Zend engine classes
(http://www.php.net/~helly/php/ext/spl/interfaceIteratorAggregate.html).

If you would rather implement the Iterator separately from your
"collection" object, implementing Iterator Aggregate will allow you to
delegate the work of iteration to a separate class, while still enabling
you to use the collection inside a foreach loop. It only has one method
to implement, getIterator() (this returns an external Iterator for the
implementing object), and once it's implemented, any object can be
"iteratable".



Cheers,
Rainer

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