Execute your code before a request is handled.
Every Vely request goes through a request dispatcher (i.e.
vely_dispatch_request() function), which is auto-generated. In order to specify your code to execute before a request is handled, create a source file "_before.v" and implement a function "void _before()", which will be automatically picked up and compiled with your application.
If no request executes (for example if your application does not handle a given
request), before-request handler does not execute either.
Here is a simple implementation of before-request trigger that just outputs "Getting Started!!":
#include <vely.h>
void _before()
{
out-header default
@Getting Started!!
}