[DomCrawler] Added argument $default to method Crawler::attr()

[Rastishka]

Q	A
Branch?	6.4
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	no
License	MIT
Doc PR	symfony/symfony-docs#...

Added argument $default to method ->attr() like ->text() and ->html() have.

[nicolas-grekas]

Do we really need this? My feeling is that we now have the ?? operator and it's nicer to use.

[antonkomarev]

I'd prefer to use native ??. It feels more obvious about the result.

[Rastishka]

Do we really need this? My feeling is that we now have the ?? operator and it's nicer to use.

Yes we need, because setting default value also prevents throwing exception when node does not exist (methods text() and html() act similar).

So this code:

try {
    $value = $dom->filter('a.someclass')->attr('href');
} catch (\InvalidArgumentException $e) {
    $value = '';
}

can be simplifies to
$value = $dom->filter('a.someclass')->attr('href', '');

[nicolas-grekas]

Thanks for the explanation. Works for me.

[nicolas-grekas]

Please also update the UPGRADE-6.4.md file, and please rebase to get rid of merge commits (PRs shouldn't contain any).

[nicolas-grekas]

Thank you @Rastishka.