Validation (vs) Sanitization in Symfony2+Twig?

1. You should not worry at all about input sanitization, Doctrine is immune to sql injection

2. By default, all output is escaped. So even if $text has script tags, it will be escaped; visible as text but not executed by browser. And if you want to have http://example.com clickable, there are jquery plugins that can do that for you.

3. I would only put validation, there is

   new Symfony\Component\Validator\Constraints\Url() ;
   

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