Thanks for the response!

Try send_error() instead. If it works, it’s more sensible anyway.

It doesn't appear to work. Same error as 'pass' and 'forward'. It seems maybe send_error() is not allowed within a before_hook.

You should be caching database connections. Re-opening it on each and every hit is a bit expensive, even for a localhost connection.

Hmmm does this code not do that? I'm using the Dancer Database plugin (and not the old plain DBI), just setting the database dynamically (based on $client) instead of from the typical ./config.yml. I assumed each database would be cached automatically by the plugin.

Why 404?

Because the routes are named /:client /:client/foo /:client/bar /:client/foo/bar/foobar etc... so, if a database for /:client doesn't exist, it means (within the context of my app) the URI doesn't exist. -----Original Message----- From: Warren Young Sent: Monday, November 09, 2015 9:57 PM To: Perl Dancer users mailing list Subject: Re: [dancer-users] Triggering 404 error from a hook On Nov 9, 2015, at 6:35 PM, Hermann Calabria <hermann@ivouch.com> wrote:

# Figure out client, if any my $client = param('client') || ''; unless ($client =~ /^[a-z0-9]{2,20}$/) { $client = ''; }

# If $client, get client dbh if ($client) {

Two lines replaces all that: my $client = param('client') || ‘'; if ($client =~ /^[a-z0-9]{2,20}$/) {

eval { var dbh => database({ driver => "mysql", host => "localhost", dbi_params => ... database => "s_".$client, ... }); }

You should be caching database connections. Re-opening it on each and every hit is a bit expensive, even for a localhost connection.

I’d like Dancer to gracefully fall through to a 404 error

Why 404? That means the URI names a nonexistent resource, which is more appropriate for something like SELECT … = 0 records. This feels more like a 500 error. Unless, that is, “missing customer DB” is something you expect your users to run into.

I’ve tried “pass” and “forward”, but I receive a cryptic “Internal Server Error” which I assume is because these keywords are not valid within hooks, but I’m not sure.

Try send_error() instead. If it works, it’s more sensible anyway. _______________________________________________ dancer-users mailing list dancer-users@dancer.pm http://lists.preshweb.co.uk/mailman/listinfo/dancer-users

We use redirect() for similar purposes here on D1, and it works. Maybe that will suffice for you.

Tried it, still got the same error. We're also using D1. However, I think I cracked it. This appears to work: if (!$client) { request->path_info('/error/notfound'); return; } Then I can either define '/error/notfound' or not, in which case no routes match which gets treated like a 404 error anyway. Perfect!

netstat -na | grep 3306.*ESTA | wc -l or sudo lsof -n | grep mysql.sock | wc -l

Thank you. Very useful trick to keep in the toolbox!

Redirecting to a login or home page is probably a more common response to that sort of error, since a 404 page doesn’t help the user fix the problem.

We have a bunch of different "clients" and they're all completely separate companies. Think "https://payroll.com/microsoft", "https://payroll.com/ibm", "https://payroll.com/apple", etc. We don't really want anyone knowing who the clients are, etc. So if they can't find their particular '/client' page, a 404 is perfect. Again, just the nuances of my particular business logic. Thanks for your help! -----Original Message----- From: Warren Young Sent: Tuesday, November 10, 2015 12:05 PM To: Perl Dancer users mailing list Subject: Re: [dancer-users] Triggering 404 error from a hook On Nov 9, 2015, at 11:16 PM, Hermann Calabria <hermann@ivouch.com> wrote:

It seems maybe send_error() is not allowed within a before_hook.

We use redirect() for similar purposes here on D1, and it works. Maybe that will suffice for you.

...

You should be caching database connections.

Hmmm does this code not do that? I'm using the Dancer Database plugin (and not the old plain DBI),

I had no idea where database() came from when I wrote that, and I don’t use that plugin anyway. If you force it to use a TCP connection by giving a host name, you can probably find out if it creates a new connection for each page load with: netstat -na | grep 3306.*ESTA | wc -l or sudo lsof -n | grep mysql.sock | wc -l (The first for TCP, the second for the Unix domain socket.)

...

Why 404?

Because the routes are named /:client /:client/foo /:client/bar /:client/foo/bar/foobar etc...

so, if a database for /:client doesn't exist, it means (within the context of my app) the URI doesn't exist.

Redirecting to a login or home page is probably a more common response to that sort of error, since a 404 page doesn’t help the user fix the problem. 404 would be appropriate if a logged-in user tried to go to /:client/foo/qux, for example: i.e. a clear case of a dead bookmark, or bogus hand-hacking of the URL. _______________________________________________ dancer-users mailing list dancer-users@dancer.pm http://lists.preshweb.co.uk/mailman/listinfo/dancer-users

On Nov 11, 2015, at 6:31 PM, Hermann Calabria <hermann@ivouch.com> wrote:

is there a way to pass parameters by modifying the request within a hook?

It sounds like you don’t yet know about the Dancer DSL “var” keyword. It will let you pass a value determined in the “before” hook down to the route handler.

And just as a reminder, this is D1, and 'forward' does not appear to work within hooks…

I don’t think you want to use “forward” here anyway. That’s for chaining route handlers, so that the route the client went to is actually handled by some other route, without redirecting the client. So, /client/lsi could actually be handled by /client/dell, and your users wouldn’t know it. I did some testing, and if this cryptic “Internal Server Error” you’re getting is just that, three words and nothing else, then never mind my previous comment. (I thought you were getting the detailed development-mode Dancer error page.) I see it here, too, but only on D1. In D2, “forward” from the “before” hook works! Replace the “get” handler in a “dancer2 -a fwdtest” app’s main module with this: hook before => sub { if (request->path =~ m{^/client}) { forward '/login' if request->path !~ m{/initech}; } }; get '/' => sub { forward '/login'; }; get '/login' => sub { template 'index'; }; get '/client/:client' => sub { return join(' ', "I am a client:", param 'client'); }; This is the sort of scheme I’m recommending. The “before” hook verifies that the client is one of the known clients, and if so, it redirects/forwards the caller to /login if it isn’t. The current “forward” code means that if you go to /client/bob, you get the login page (really, the default index page) but the URL in the browser’s Location bar remains /client/bob. If you change it to a redirect call, the browser loads /login itself, which I think makes more sense; plus, it works on D1. By the way, I had to move :client underneath /client to avoid a redirect loop here, since a variable at the top level basically matches everything. You need to give Dancer’s route handler some unique bit to avoid this.