# [RFC] Phasing out Serializable

- Thread: https://externals.io/message/112454
- Original archive: https://news-web.php.net/php.internals/112454
- Started by Nikita Popov on 2020-12-07T14:11:07+00:00
- Messages: 9
- RFC: Phasing out Serializable (Accepted) — https://externals.io/rfc/phase_out_serializable.md
- RFC: New custom object serialization mechanism (Implemented (PHP 7.4)) — https://externals.io/rfc/custom_object_serialization.md
- Reply by email to internals@lists.php.net
- More for agents: search with https://externals.io/search.md?q={query} · RFCs at https://externals.io/rfc.md · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt

---

## #112454 — Nikita Popov — 2020-12-07T14:11:07+00:00

URL: https://externals.io/message/112454#112454

Hi internals,

Picking up a loose thread:
https://wiki.php.net/rfc/custom_object_serialization introduced a
replacement for Serializable in PHP 7.4, so it's time to think about
deprecating and removing the old mechanism:

https://wiki.php.net/rfc/phase_out_serializable

This RFC follows a rather conversative approach. In PHP 8.1 there will be a
deprecation warning if Serializable is implemented without also
implementing __serialize() and __unserialize(). In PHP 9.0, support for
Serializable is dropped internally, and only the interface retained. In PHP
10.0 the interface is dropped as well.

Regards,
Nikita

---

## #112455 — bjorn.x.larsson@telia.com — 2020-12-07T14:49:04+00:00

URL: https://externals.io/message/112454#112455 · In reply to: #112454

Den 2020-12-07 kl. 15:11, skrev Nikita Popov:

> Hi internals,
>
> Picking up a loose thread:
> https://wiki.php.net/rfc/custom_object_serialization introduced a
> replacement for Serializable in PHP 7.4, so it's time to think about
> deprecating and removing the old mechanism:
>
> https://wiki.php.net/rfc/phase_out_serializable
>
> This RFC follows a rather conversative approach. In PHP 8.1 there will be a
> deprecation warning if Serializable is implemented without also
> implementing __serialize() and __unserialize(). In PHP 9.0, support for
> Serializable is dropped internally, and only the interface retained. In PHP
> 10.0 the interface is dropped as well.
>
> Regards,
> Nikita

Given that 10.0 lies maybe ten years in the future if we have a similar 
timeline
like for 7.0 to 8.0. Is it then realistic to have such a long-term 
planning? For me
it feels a bit more prudent to remove it completely in 9.0.

Otherwise +1!

r//Björn L

---

## #112458 — Nikita Popov — 2020-12-07T15:49:53+00:00

URL: https://externals.io/message/112454#112458 · In reply to: #112455

On Mon, Dec 7, 2020 at 3:49 PM Björn Larsson <bjorn.x.larsson@telia.com>
wrote:

> Den 2020-12-07 kl. 15:11, skrev Nikita Popov:
>
> > […]
> be a
> > […]
> PHP
> > […]
>

I had to slightly extend this RFC to also deprecate & remove the
PDO::FETCH_SERIALIZE mode, which is based on Serializable. Doesn't seem to
be a big loss, as this fetch mode isn't working correctly in the first
place...


> Given that 10.0 lies maybe ten years in the future if we have a similar
> timeline
> like for 7.0 to 8.0. Is it then realistic to have such a long-term
> planning? For me
> it feels a bit more prudent to remove it completely in 9.0.
>
> Otherwise +1!
>

I'd be also okay with dropping it entirely in PHP 9. That would mean that
there is no prior deprecation warning if you implement it together with
__serialize() and __unserialize() though, which is why I went with the
proposed timeline. From my own (technical) perspective, the case is closed
in PHP 9 either way, because that's where we can rip out support in
 `unserialize()`.

Nikita

---

## #112497 — Nicolas Grekas — 2020-12-14T17:40:22+00:00

URL: https://externals.io/message/112454#112497 · In reply to: #112458

Hi Nikita,


> > […]
>

thank you for the RFC, I fully support it!



> I had to slightly extend this RFC to also deprecate & remove the
> PDO::FETCH_SERIALIZE mode, which is based on Serializable. Doesn't seem to
> be a big loss, as this fetch mode isn't working correctly in the first
> place...
>
>
> > […]
>
> I'd be also okay with dropping it entirely in PHP 9. That would mean that
> there is no prior deprecation warning if you implement it together with
> __serialize() and __unserialize() though, which is why I went with the
> proposed timeline. From my own (technical) perspective, the case is closed
> in PHP 9 either way, because that's where we can rip out support in
> `unserialize()`.
>

I think it's critical to create a smooth path, and the one you propose is
very sensible to me. We're not in a hurry to remove the interface. It
should just be super clear what the direction is, and this path with a
deprecation works well IMHO.

Nicolas

---

## #112509 — bjorn.x.larsson@telia.com — 2020-12-14T23:13:44+00:00

URL: https://externals.io/message/112454#112509 · In reply to: #112458

Den 2020-12-07 kl. 16:49, skrev Nikita Popov:
> On Mon, Dec 7, 2020 at 3:49 PM Björn Larsson <bjorn.x.larsson@telia.com>
> wrote:
> 
> > […]
> 
> I had to slightly extend this RFC to also deprecate & remove the
> PDO::FETCH_SERIALIZE mode, which is based on Serializable. Doesn't seem to
> be a big loss, as this fetch mode isn't working correctly in the first
> place...
> 
> 
> > […]
> 
> I'd be also okay with dropping it entirely in PHP 9. That would mean that
> there is no prior deprecation warning if you implement it together with
> __serialize() and __unserialize() though, which is why I went with the
> proposed timeline. From my own (technical) perspective, the case is closed
> in PHP 9 either way, because that's where we can rip out support in
> `unserialize()`.
> 
> Nikita
> 
Not sure I understand why no deprecation warning is needed in 8.1,
if removing completely in 9.0?

Anyway, my main objection towards the proposed timeline is not so
much about the functionality removed. It's more related with that
I think an RFC that mandates what should happen in 10.0, maybe
10 years into the future feels a bit farfetched.

Of course there could be exceptions for RFC's targeting PHP 10.0,
but then I think it should be for something big, like replacing
the SPL library etc.

r//Björn L

---

## #112511 — Paul Crovella — 2020-12-15T00:17:52+00:00

URL: https://externals.io/message/112454#112511 · In reply to: #112509

> an RFC that mandates what should happen in 10.0, maybe
> 10 years into the future feels a bit farfetched.

It's more of a default unless another RFC changes the plan rather than
a mandate. Given the plan here it seems a reasonable default.

---

## #112784 — Nikita Popov — 2021-01-06T16:51:24+00:00

URL: https://externals.io/message/112454#112784 · In reply to: #112509

On Tue, Dec 15, 2020 at 12:14 AM Björn Larsson <bjorn.x.larsson@telia.com>
wrote:

> Den 2020-12-07 kl. 16:49, skrev Nikita Popov:
> > […]
> to
> > […]
> closed
> > […]
> Not sure I understand why no deprecation warning is needed in 8.1,
> if removing completely in 9.0?
>

The current proposed timeline only removes in PHP 9.0 what was deprecated
in PHP 8.1. Possibly I'm misunderstanding what you have in mind here.

Anyway, my main objection towards the proposed timeline is not so
> much about the functionality removed. It's more related with that
> I think an RFC that mandates what should happen in 10.0, maybe
> 10 years into the future feels a bit farfetched.
>
> Of course there could be exceptions for RFC's targeting PHP 10.0,
> but then I think it should be for something big, like replacing
> the SPL library etc.
>

I'm not sure I understand what your actual concern here is. Yes, it's a
long-term plan, but why is that a problem? Why should long-term planning
only be limited to major changes? Even a simple deprecation already works
on a 5 year timeline, between deprecation and removal. Of course, I have no
idea whether I'll still be involved with the PHP project in ten years time,
but I suspect there will always be someone who enjoys deleting deprecated
code to carry out the will ;)

Regards,
Nikita

---

## #112807 — bjorn.x.larsson@telia.com — 2021-01-07T23:23:27+00:00

URL: https://externals.io/message/112454#112807 · In reply to: #112784

Den 2021-01-06 kl. 17:51, skrev Nikita Popov:

> On Tue, Dec 15, 2020 at 12:14 AM Björn Larsson 
> <bjorn.x.larsson@telia.com <mailto:bjorn.x.larsson@telia.com>> wrote:
>
>     Den 2020-12-07 kl. 16:49, skrev Nikita Popov:
> > […]
>     <bjorn.x.larsson@telia.com <mailto:bjorn.x.larsson@telia.com>>
> > […]
>     <https://wiki.php.net/rfc/custom_object_serialization> introduced a
> > […]
>     about
> > […]
>     <https://wiki.php.net/rfc/phase_out_serializable>
> > […]
>     there will
> > […]
>     support for
> > […]
>     retained. In
> > […]
>     Doesn't seem to
> > […]
>     first
> > […]
>     similar
> > […]
>     such a
> > […]
>     mean that
> > […]
>     together with
> > […]
>     with the
> > […]
>     is closed
> > […]
>     Not sure I understand why no deprecation warning is needed in 8.1,
>     if removing completely in 9.0?
>
> The current proposed timeline only removes in PHP 9.0 what was 
> deprecated in PHP 8.1. Possibly I'm misunderstanding what you have in 
> mind here.

Ok, then I read it wrong, completely fine with above.
>
>     Anyway, my main objection towards the proposed timeline is not so
>     much about the functionality removed. It's more related with that
>     I think an RFC that mandates what should happen in 10.0, maybe
>     10 years into the future feels a bit farfetched.
>
>     Of course there could be exceptions for RFC's targeting PHP 10.0,
>     but then I think it should be for something big, like replacing
>     the SPL library etc.
>
>
> I'm not sure I understand what your actual concern here is. Yes, it's 
> a long-term plan, but why is that a problem? Why should long-term 
> planning only be limited to major changes? Even a simple deprecation 
> already works on a 5 year timeline, between deprecation and removal. 
> Of course, I have no idea whether I'll still be involved with the PHP 
> project in ten years time, but I suspect there will always be someone 
> who enjoys deleting deprecated code to carry out the will ;)


Not sure we had RFC's earlier with a ten year lifespan. So I have
a concern about how realistic it would be ;-) The RFC is targetting
two major versions, think it would be cleaner to target only one
of them, not two.

Now we have this RFC for 8.1 and we remove it it in the first step in
9.0 followed by removing it completely in 10.0. One motive for this
as I understand it, is the <7.4 support.

Anyway, come to think on the RFC "Remove PHP 4 Constructors"
which targeted 7.0 and then it was removed completely in 8.0.
Also thinking on the 7.4 deprecation RFC, where the items was
removed in 8.0.

So is it by having this RFC targeting 8.1, we get five extra years
or is it the <7.4 support?

r//Björn L

---

## #112851 — bjorn.x.larsson@telia.com — 2021-01-12T16:22:15+00:00

URL: https://externals.io/message/112454#112851 · In reply to: #112807

Den 2021-01-08 kl. 00:23, skrev Björn Larsson:

> Den 2021-01-06 kl. 17:51, skrev Nikita Popov:
>
> > […]
>
> Ok, then I read it wrong, completely fine with above.
> > […]
>
>
> Not sure we had RFC's earlier with a ten year lifespan. So I have
> a concern about how realistic it would be ;-) The RFC is targetting
> two major versions, think it would be cleaner to target only one
> of them, not two.
>
> Now we have this RFC for 8.1 and we remove it it in the first step in
> 9.0 followed by removing it completely in 10.0. One motive for this
> as I understand it, is the <7.4 support.
>
> Anyway, come to think on the RFC "Remove PHP 4 Constructors"
> which targeted 7.0 and then it was removed completely in 8.0.
> Also thinking on the 7.4 deprecation RFC, where the items was
> removed in 8.0.
>
> So is it by having this RFC targeting 8.1, we get five extra years
> or is it the <7.4 support?
>
> r//Björn L
>
After thinking a bit more my objection is twofold. One is the long 
timeline, targetting 10.0 and at least for me it's not clear why not 
having 9.0 as the endpoint is good enough.

Secondly, we introduce a three step approach, targetting both 8.1, 9.0 
and 10.0. Is this something that also could come into play for other 
deprecations and what is then the criteria for it?

Like the planned 8.1 deprecations:
- https://wiki.php.net/rfc/deprecations_php_8_0

r//Björn L
