2009/5/7 Richard Quadling <rquadling@xxxxxxxxxxxxxx>:
> 2009/4/30 Olivier Lalonde <olalonde@xxxxxxxxx>:
>> Hi all,
>>
>> Since I can't do $this = new Class(); within my class (it gives an
>> error), I was looking for ways to get the same result by other means.
>>
>> I am actually working on an ORM and trying to implement lazy loading.
>>
>> $book = $orm->getBook('id'); // returns an Orm object
>> $book->load();
>>
>> // $book should now be a Book instead instead of an Orm instance
>>
>> Of course, I oversimplified the problem. $book = $orm->getBook('id');
>> doesn't return a Book instance right ahead because it is a chained
>> method (i.e. $orm->getBook()->where(...)->prefetch(...)->etc....
>> Therefore, it _has_ to return an Orm instance.
>>
>> Now, why not simply add ->load() at the end of the chain? Because it
>> adds an extra step for developers that doesn't bring meaningful
>> information. Instead of doing $book = $orm->getBook('id');, it would
>> mean having to do $book = $orm->getBook('id')->load(); (which is
>> longer to type :p). That's why I wanted to implement "lazy loading".
>>
>> $book = $dorm->getBook('id');
>> echo $book->title; // title should be trapped by __set() and it should
>> dynamically replace $book by an actual Book instance
>>
>> I tried doing the following, but PHP doesn't allow it:
>>
>> class A {
>> public function transform() {
>> $this = new B();
>> }
>> }
>>
>> class B {}
>>
>> $var = new A();
>> $var->transform();
>>
>> This is not currently supported by PHP and I was wondering if there
>> was anyway of getting around the problem, that doesn't involve
>> 1) passing $var to the A class i.e:$var->var = $var;
>> 2) looping $GLOBALS[]
>> 3) using __call,__get and __set to proxy everything to the actual Book object
>>
>> PS1: don't lecture me about how I'm doing this all wrong. I've looked
>> at the problem from every possible angle and this is the only
>> solution.
>> PS2: Another alternative would be to subclass the Orm object with
>> Book, (class Orm extends Book {}), overload all properties/methods so
>> we can catch when to load the object... but that would be an extreme
>> pain in the ass.
>> PS3: Another alternative would be to have a parameter that
>> enables/disables chaining.
>> $dorm->getBook('id', true); // chain (you now have to add ->load() at
>> the end of the chain)
>> $dorm->getBook('id', false); // dont chain, this returns a Book instance
>>
>> The point of all this is to keep the most friendly interface !
>>
>> Cheers,
>> Olivier
>>
>> --
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>>
>>
>
> In $orm->getBook('id') should be something similar to ...
>
> $book = new ClassBook('id');
> $book->load;
> return $book;
>
> surely?
>
> --
> -----
> Richard Quadling
> Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731
> "Standing on the shoulders of some very clever giants!"
>
Oops.
$book->load();
Sorry.
--
-----
Richard Quadling
Zend Certified Engineer : http://zend.com/zce.php?c=ZEND002498&r=213474731
"Standing on the shoulders of some very clever giants!"
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