Comments on: I want enums in PHP

By: dagfinn

dagfinn — Fri, 23 May 2008 13:26:02 +0000

Thanks. I see your point; it does feel wrong. My point is avoiding bugs that are hard to find. That’s why I want to get a hard, loud error message when I misspell the role name. Using error_reporting() as someone suggested is not quite strong enough.

By: stereofrog

stereofrog — Fri, 23 May 2008 12:43:12 +0000

finally got time to click your sig on sitepoint. Nice blog you have here!

I understand your concerns about strings vs constants. I don't think the problem with "if($role == 'administrator')" is that is can be misspelled (so can the constant too), but it just "feels" wrong. "Look, it's quoted, it a literal value and we dont like literals in our code". What actually would be helpful here is a rubys interning operator (colon). :foobar in ruby basically says "I dont care how exactly this is stored, the point is when I'm using this here and there I'm referring to the same thing"

By: tawfiq

tawfiq — Wed, 21 May 2008 08:48:52 +0000

if(ereg("ADMINISTRATOR",$roles))

please go to be enums in php
and than go to the hell

By: dagfinn

dagfinn — Tue, 13 May 2008 06:35:10 +0000

One (probably last) comment to the off-topic discussion started by Derick. Expressions like “meaningless” and “do your homework” give (me, and probably others) an impression of implied critcism. If that was the intention, it’s not clear and specific enough to be useful to me as such. So I will choose to assume that the impression is a misunderstanding, and that Derick’s intention was simply to give information.

By: Jeff Ray

Jeff Ray — Tue, 13 May 2008 06:31:28 +0000

I agree with Nick Lo that promoting discussion is a good way to "do your homework". Just because someone hasn't submitted a bug or change request yet, that doesn't mean they won't eventually submit one after having some good pier review of the concern. Lay off guys...

On topic, I thing Enums would be a handy thing as well. Is it critical? No. Would it be useful in some situations? Yes.

I would say that there are multiple ways to get around enums not being present, and there are probably more times than not that a constant or a static constant class would be an equally functional fit. But there are times when you can just tell as a programmer, that a situation is ideal for enums, and finding a workaround just seems awquard.

It would be good to have them. Does the absence of enums detract from the functionality of the language? Probably not.

By: Nick Lo

Nick Lo — Mon, 12 May 2008 23:29:57 +0000

@Derick: “Your blog has no meaning for the PHP developers, as they’re way to busy with other things – remember that.” Similarly many developers (and I don’t just mean PHP developers) have little time for the PHP internals as they’re way too busy with other things!

I think it was quite clear that Dagfinn was merely raising a topic of conversation which in many ways IS a way to “do your homework” by inviting different ideas.

By: Nick

Nick — Mon, 12 May 2008 15:55:30 +0000

Instead of using an object just for that - which is an extra overhead to the server - you can use constants. Here is an example :

define ( 'ADMINISTRATOR', 1 );
define ( 'REGULAR', 2 );

if ( $user == ADMINISTRATOR ){
....
}

By: dagfinn

dagfinn — Mon, 12 May 2008 06:43:31 +0000

@Ben Ramsey: I can see I need to think more about how I would want enums to actually work in PHP. I may be giving the impression that I have strong opinions while actually I’m just thinking out loud.

By: Philip Olson

Philip Olson — Mon, 12 May 2008 04:10:01 +0000

These days some people write blog posts instead of using official means like writing an RFC, a mailing list, and/or filling out a bug report. I think all Derick is saying is don't expect this feature request to be remembered without using official means.

And on a related topic, what bugs me [and likely others] most is when people blog about a bug and essentially scream "I found a bug! I found a bug! I found a bug!!!" which ends up on PHP Planet and, well, it's annoying. Not that you did that... but just saying.

By: Ben Ramsey

Ben Ramsey — Mon, 12 May 2008 01:00:48 +0000

I also meant to point out that, while it may be obvious to many, not everyone will notice that this is what an enum is essentially doing. When you do this:

public enum Role { REGULAR, WEBMASTER, ADMINISTRATOR };

Think of it like this:

constant REGULAR = new Role(0);
constant WEBMASTER = new Role(1);
constant ADMINISTRATOR = new Role(2);

Obviously, this isn’t possible in PHP right now, but it illustrates how to think of enums.

You would now have constants that have been initialized as the Role “class,” and you can statically call them on the class and access their methods:

MyProject_Authorization_RBAC_Role::REGULAR->getPerms()

Perhaps I should’ve written my own blog post since my response has turned out to be pretty long.