Edit report at http://bugs.php.net/bug.php?id=49526&edit=1
ID: 49526
Comment by: rayro at gmx dot de
Reported by: president at basnetworks dot net
Summary: C# style property get/set syntax
Status: Open
Type: Feature/Change Request
Package: Feature/Change Request
PHP Version: 6SVN-2009-09-11 (SVN)
Block user comment: N
New Comment:
I also recommend this but i have a little idea too:
1. Most of the time i use get<VariableName>() syntax and I have to write
new functions for that (or using __call or __set), because i protect the
properties with private or protected to protect for writing them.
2. Most of all the code is ugly or has limitations using
readonly/writeonly properties with __get(&$v) or __set($v,&$c) by
reference.
3. It is not perfectly clean to write less code with __get or
getter/setter if only want to protecting them... And less code matters!
I would like to see a new, or 2 new keywords, e.g. "readonly" and
"writonly", because the code will look smoother and i dont have to make
the use of magic methods... Or some own designed errors for that...
Now an simple example:
======================
<?php
class A
{
/** the following syntax is just invented **/
static readable protected $foo = 1;
static writable protected $bar = 2;
}
A::$foo++; // raises error "variable is not writeable from this
context"
echo(A::$foo); // will simple echo $foo
A::$bar++; // will increment $bar to 3
echo(A::$bar); // raises error "variable is not readable from this
context"
?>
( what about is_readable() or is_writable() for that? )
I dont think that these functions will be used, so only Reflection
should be extended...
and now, instead of the current syntax:
======================================
<?php
class A
{
static protected $foo = 1;
static protected $bar = 1;
function __get($v) {
if ($v == 'bar') {
trigger_error('$bar is not readble from this
context',E_USER_ERROR);
}
return $this->$v;
}
function __set($v, $c)
{
if ($v == 'foo') {
trigger_error('$foo is not writable from this
context',E_USER_ERROR);
}
$this->$v = $c;
return true;
}
}
?>
get/set syntax will be nice but also nasty if only read/writablity is
desired...
this can be confusing as this:
==============================
<?php
class A
{
/** the following syntax is just invented **/
static protected $foo {
function __get() {
return $this->foo;
}
function __set() {
trigger_error('$foo is not writable from this
context',E_USER_ERROR);
}
} = 1;
static protected $bar {
function __get() {
trigger_error('$bar is not readable from this
context',E_USER_ERROR);
}
function __set() {
$this->bar = 1;
return true;
}
} = 2;
}
?>
think about it... many developers will waive the old way or functions
like getVarname and setVarname... and for all other, getter/setter will
be nice as described in the rfc...
Previous Comments:
------------------------------------------------------------------------
[2009-09-13 19:56:24] president at basnetworks dot net
For reference, the RFC for this feature request now exists at this URL:
http://wiki.php.net/rfc/propertygetsetsyntax
------------------------------------------------------------------------
[2009-09-13 04:24:08] president at basnetworks dot net
Hi Kalle,
Thanks for the information. I will follow your instructions and start
working on the RFC over the next week(s). Also, thanks for the link
about the Developer Summit, but it does not show the outcome of the
discussion, am I able to find that anywhere?
------------------------------------------------------------------------
[2009-09-12 12:22:19] ka...@php.net
Hey
The best way to request this feature is to write an RFC in our wiki at:
http://wiki.php.net/rfc/
Request an account at:
http://wiki.php.net/start?do=register
And then send an email to the webmaster list
(php-webmas...@lists.php.net) requesting write access to the rfc
namespace and repost this feature request as an RFC. When you are done,
start a new thread on internals (intern...@lists.php.net) explaining
your RFC.
As for reference, this idea was discussed at the last PDM in May, see:
http://wiki.php.net/summits/pdmnotesmay09#php_6 point #16
------------------------------------------------------------------------
[2009-09-11 01:02:26] president at basnetworks dot net
Description:
------------
I would like to request a C# style get/set syntax (called a property in
C#) for PHP. Basically, it looks and acts like a class member/variable
from outside the class, but it is actually a set of two methods. It can
be used to provide only read or write access to a class member, do pre
or post processing on a member, or be completely dynamic like a set of
class methods.
A property contains two methods between braces, named get and set. get
must always have a return statement, while set has a magic variable
"value" or "$value" which is the variable that was passed to the
property. Either method can be omitted to make the property read-only
or write-only.
The same effect can be achieved by creating a GetVar() and SetVar()
method to create a sudo-property "var", although it is by far much
clumsier and less intuitive.
I also realize the same effect received outside the class can be
achieved using the __get() and __set() methods, but these methods are
only really useful in a small instance of situations, like giving access
to an internal array as though each index is a property. These magic
methods are not at all useful for using on an individual property basis,
and it gets worse when inheritance is introduced.
The C# syntax is as follows:
class TimePeriod
{
private double seconds;
public double Hours
{
get { return seconds / 3600; }
set { seconds = value * 3600; }
}
}
The PHP syntax would be similar to the following:
class TimePeriod
{
private $seconds;
public property Hours
{
get { return $this->seconds / 3600; }
set { $this->seconds = $value * 3600; }
}
}
You would use it exactly the same as a public class member:
$time = new TimePeriod();
$time->Hours = 24;
echo $time->Hours;
As opposed to the alternative:
$time = new TimePeriod();
$time->SetHours(24);
echo $time->GetHours();
Additionally, the get and set methods can have separate visibilities
like in the following example where get is public and set is protected:
public property Name
{
get { return $this->name; }
protected set { $this->name = $value; }
}
There is another ticket that is similar but not the same thing here:
http://bugs.php.net/bug.php?id=34194
It suggests separate getter/setter methods, which in my opinion are much
less intuitive. I believe that following the C# format would help to
keep a standard format, and would be the least confusing.
The poster of that bug also fails to realize that separate visibility
levels can be achieved for properties using the C# syntax, as shown
above.
The C# documentation on properties is available here:
http://msdn.microsoft.com/en-us/library/x9fsa0sw%28VS.80%29.aspx
The C# documentation on Asymmetric Accessor Accessibility for properties
is available here:
http://msdn.microsoft.com/en-us/library/75e8y5dd%28VS.80%29.aspx
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=49526&edit=1
