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In-Reply-To: <alpine.DEB.2.23.453.2103150917420.2842@singlemalt.home.derickrethans.nl>
Date: Mon, 15 Mar 2021 10:22:56 +0100
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 <alpine.DEB.2.23.453.2103150917420.2842@singlemalt.home.derickrethans.nl>
To: Derick Rethans <derick@php.net>
Subject: Re: [PHP-DEV] Add __toString() to DateInterval
From: m@9dev.de (Moritz Friedrich)

I would assume the moment I call some kind of ISO conversion or =
serialization method on a dynamic interval, I=E2=80=99d receive output =
relative to now. `createFromDateString` creates the interval relative to =
now, so why shouldn=E2=80=99t the reverse hold true?

Regards,
Moritz

> Am 15.03.2021 um 10:18 schrieb Derick Rethans <derick@php.net>:
>=20
> On Wed, 3 Mar 2021, Moritz Friedrich wrote:
>=20
>> I would like to propose adding a `__toString()` method to the=20
>> `DateInterval` class that should return a valid ISO8601 interval=20
>> (https://en.wikipedia.org/wiki/ISO_8601#Time_intervals). As it =
stands,=20
>> the class supports creating instances from such interval strings=20
>> passed to its constructor, but the reverse isn=E2=80=99t true: The =
only way to=20
>> build a string representation of the interval is by querying the=20
>> `DateInterval::format` method for the individual durations multiple=20=

>> times (see=20
>> =
https://stackoverflow.com/questions/33787039/format-dateinterval-as-iso860=
1#answers=20
>> for examples).
>=20
> The DateInterval class can also contain intervals that can't be=20
> represented with such an ISO string. For example, how are you going to=20=

> do:
>=20
> $dt =3D DateInterval::createFromDateString( "next weekday" );
>=20
> or
>=20
> $dt =3D DateInterval::createFromDateString( 'next Monday 02:00' );
>=20
> __toString needs to work in every case, and I don't think you can do=20=

> that with ISO 8601 interval strings.
>=20
> cheers,
> Derick
>=20
> --=20
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