[Intl] deprecate polyfills in favor of symfony/polyfill-intl-icu

[nicolas-grekas]

Q	A
Feature PR	symfony/symfony#38974
PR author(s)	@nicolas-grekas
Merged in	5.x

[javiereguiluz]

I'm closing this one as "nothing to fix" because, as mentioned in the original issue (symfony/symfony#37758):

The only impact would be on projects requiring symfony/polyfill-intl-icu and actually using the symfony/intl APIs without noticing they don't define a requirement for them, as symfony/intl might not be installed anymore. But the symfony/polyfill-intl-icu package does not document that these APIs become available due to the implementation details.

[Tobion]

I think https://symfony.com/doc/5.3/components/intl.html needs to be updated for this. So maybe it's good to reopen this.

[javiereguiluz]

I don't understand the changes we need to do in https://symfony.com/doc/5.3/components/intl.html:

• Instead of composer require symfony/intl we must tell developer to install symfony/polyfill-intl-icu?
• Should we tell them to install symfony/polyfill-intl-icu but only if they need to access to Country/Language/etc. data?
• Does this symfony/polyfill-intl-icu package must be installed but only optionally if you want to access to Country/Language/etc. data and your local PHP installation doesn't provide it?

Thanks!

[Tobion]

This component provides access to the localization data of the ICU library. It also provides a PHP replacement layer for the C intl extension.

Only the first sentence in the documentation is correct. The polyfill for the intl extension is deprecated and people should use symfony/polyfill-intl-icu instead.

So this part of the intl component doc can also be removed

If you install the component via Composer, the following classes and functions of the intl extension will be automatically provided if the intl extension is not loaded: ...