Contributed by
Maxime Steinhausser
in #22554.

Symfony 3.4 will be released in November 2017, alongside Symfony 4.0. This is the first article of the series that shows the most important new features introduced by this Symfony version.

In Symfony 3.4, the web debug toolbar and the profiler will include a new panel for the Validator component operations:

Although the current Forms panel already includes validation information, there are other use-cases where you're likely to call the validator. The purpose of this panel is to collect every call made to the validator (e.g. ValidatorInterface::validate()) along with detailed information about them.

For example, when dealing with APIs and mobile apps, it's not always easy to get the response body to find out what's wrong with the call. This new panel makes much easier to get those details without accessing the API response.

Each validator call is shown as an entry in the new panel. This image shows a single successful entry fully expanded: