Conditional profiling

Symfony profiler provides an immense amount of debug information to quickly find
the cause of any problem. However, that comes at a price, because the profiler
must collect all that information while serving the request. This can slowdown
the application even for requests where you don’t look at the profiler
information (which are most of them).

In Symfony 5.4 you can enable the profiler conditionally. To do that, add
these two new config options:

The collect: false option disables the profiler by default and the
collect_parameter: profile option enables it for requests that include the
profile query parameter.

You can freely choose the query parameter name and you can also enable the
profiler by submitting a form field with that name (useful for POST requests)
and even a request attribute.

More security information in the profiler

First, the web debug toolbar now shows all the security roles of the logged in
user. This way you can quickly check both the roles assigned directly to the
user and the roles assigned to them via security roles inheritance:

Second, the security profiler panel includes a new tab called „Authenticators“
where you can check the security authenticators that were called during the
request:

HTML email preview

The Symfony profiler includes an „Emails“ panel where you can inspect the details
of the emails sent during the processing of the request. When the email is complex,
checking its HTML contents is not practical. In Symfony 5.4 we’re improving this
panel to also preview the rendered HTML contents of the email: