2013/5/2 Bernhard Schussek <bschus...@gmail.com> > 2013/5/1 Rasmus Schultz <ras...@mindplay.dk> > > > > One could > > > write a PropertyReference class right now with literally the only > > > difference being the lack of a builtin operator (ie new > > > PropertyReference($obj, 'prop') versus ^$obj->prop): the fact that > > > nobody seems to have done this in a major framework I know of suggests > > > that there isn't a strong need for encapsulating the indirection > > > beyond the $obj->$prop syntax that's worked forever. > > > > > > > Look at the Symfony form-builder example - encapsulating the indirection > is > > *precisely* what they're doing: the object reference is stored in the > > form-builder, and property-names are added subsequently. > > > > As the developer of the Symfony Form component, I would like to clarify > that this is not true. At the time the property reference is stored, the > object it refers to is not (necessarily) known. You could build an abstract > form definition for "Author" instances, but only later instantiate a form > for that definition with a concrete object. So to be really useful in a > form context, property references need to be separated from object > instances (something like "^Author::$firstName" could work). > > Second, it is important that references can span multiple nodes in an > object/array graph. In Symfony, we built the PropertyAccess component for > that [1] which allows references like > > "authors[0].personalDetails[firstName]" > > which translates to > > ->getAuthors()[0]->getPersonalDetails()['firstName'] > > or > > ->authors[0]->getPersonalDetails()['firstName'] > >
I have an idea regarding the syntax. The suggested ^ operator is troublesome, because it does not make clear that whatever follows will not be evaluated. This becomes even more confusing when dealing with multiple nodes, as the example above, where part of the expression has to be evaluated. Let's have something different: $obj~>property MyClass::~property This syntax can be easily applied to multiple nodes, without confusion: ->getAuthors()[0]->getPersonalDetails()~>firstName And it can be applied statically: Author::~firstName Lazare Inepologlou Ingénieur Logiciel
