string cant be null error

[MrFastDie]

fix for

[2021-05-18 13:57:54] app.CRITICAL: An exception occurred. {"exception":"[object] (Symfony\Component\Debug\Exception\FatalThrowableError(code: 0): Type error: Argument 2 passed to Hofff\Contao\SocialTags\EventListener\Hook\NewsReaderListener::onGetContentElement() must be of the type string, null given, called in /var/www/html/staging/vendor/contao/core-bundle/src/Resources/contao/library/Contao/Controller.php on line 484 at /var/www/html/staging/vendor/hofff/contao-social-tags/src/EventListener/Hook/NewsReaderListener.php:43)"} []

[dmolineus]

A content element should always generate a string, so I don't think the fix is needed. Furthermore the broken content element has to be fixed.

[MrFastDie]

A content element should always generate a string, so I don't think the fix is needed. Furthermore the broken content element has to be fixed.

I don't fully agree here

Because first of all I don't get any information about which element needs to get fixed

And that problem occured on a client system which I don't maintain. But thinking of that creating a content element without a string is posible - so I would like to see that fix in anyways.

I think we both could aggree on "it should always have" declarations are not a habit.

[dmolineus]

Following the type documentation of a frontend module and content element, it must generate a string. (See https://github.com/contao/contao/blob/e44fcbcc25bacde033e9919a079b777105381cdf/core-bundle/src/Resources/contao/modules/Module.php#L204-L208). I know it's a weak type information, as it's part of the legacy code of Contao. But still implementations has to stick to it, otherwise it will lead to unforseen errors like this one.

[MrFastDie]

The major difference is that Contao is using phpdoc to create typehints.

This file on the other hand is using declare(strict_types=1); - which makes the hints to be forced to explicit types. As Contao is not using this feature it's still possible to get this error...

So we should either remove the strict_types according to the contao code, or adjust the string to actually be null.

[fritzmg]

I agree with @dmolineus, the Content Element in question needs to be fixed to return a string.

[dmolineus]

Thanks for your PR. I won't merge it as it would avoid symptoms but not fixing the root issue,