Some important implications I forgot to mention:

* No more global state is used

* No more semi-dependency from DataModel on lib

* getPrefixedId is no longer evil and thus not deprecated any more

* EntityId and derivatives no longer expose the id format. A FooIdDerivative that has a md5 in it can be created if that'd make sense

* One can type hint against ItemId or PropertyId, which are guaranteed to be valid ids for the correct entity type

To help understand the usage changes, here are 2 examples:

1. When constructing an id programmatically:

Old way: $itemId = new EntityId( 'item', 42 );
New way: $itemId = new ItemId( 'q42' );

2. When deserializing an item id (for instance in an API module):

Old way: $idParser = getParserSomehow(); $itemId = $idParser->parse( $serialization );

New way: $itemId = new ItemId( $serialization );

(Error handling omitted for readability, as its the same in both cases anyway.)

Cheers

--
Jeroen De Dauw
http://www.bn2vs.com
Don't panic. Don't be evil. ~=[,,_,,]:3
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