>PHP has interfaces for this kind of thing, and they're clearer/cleaner
>to use than the code you've posted (for this case at least).
Interfaces don't really provide this sort of functionality - take a look at c#,
java or ruby to see
better examples than mine of how attributes are used.
I suppose you can think of interfaces as providing a sort of binary-valued
attribute system for classes,
but they don't work for properties or methods.
Doing this with docblocks would be *horribly* inefficient. I know historically
we've used docblocks in php to add
metadata to things, but that came about because we didn't have a visibility
mechanism or type hints on parameters.
And anyway we don't store docblocks for properties.
[Aside]
In the present engine method docblocks are stored, but this is not really
necessary since the line and file the
method is defined in is also stored and could be used to pull the comments from
the source on-the fly.
A look-aside caching mechanism could be used to export these for encoded files.
[/Aside]
I agree that my example is not the best example of how attributes can be used,
it was more to show syntax.
That said it would make the job of automating object-relational type code much
easier. Example below.
The only way to do this currently is to implement some sort of properties()
method on a class
which returns e.g. a list of Property objects containing the name of the
property each relates to, and a further list of
that property's attributes. That's bad because the attributes then don't belong
to the property.
The implementation in the Zend engine is to store the attributes as a string in
the zend_property_info, so they would take little extra space.
!-------- example (all sorts of problems with this, but you get the idea)
------------!
class DBObject {
public $dbid;
function save() {
$db = DB::handle();
$values="";
$comma="";
foreach($this as $propname => $prop) {
if($propname=="dbid") continue;
$rp = new
ReflectionProperty(get_class($this),$propname);
if(!$rp->getAttributeValue("persist")) continue;
$s = $rp->getAttributeValue("serialize);
if(!is_null($s)) {
$val = $prop->toString();
} else {
$val = $prop;
}
$query.="$comma$propname='".addslashes($val)."'";
$comma=",";
}
$db->query("UPDATE ".$this->tableName()." SET $values WHERE
dbid=$this->dbid");
}
}
class Person extends DBObject {
[persist:true] public $firstName; // string value
[persist:true] public $lastName; // string value
[persist:true; serialize:true] public $dateOfBirth; // CDate
function __construct() {
$this->dateOfBirth = new CDate();
}
}
!------------- /example -----------!
--
-----------------------------------------------------------------
Duncan McIntyre
Director
Calligram Ltd
71 Madeley Road
Ealing, London W5 2LT
[EMAIL PROTECTED]
(+44) 208 997 6241 - Office
(+44) 7919 050 239 - Mobile
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