[Dancer-users] App responding differently to ajax calls under plackup than Apache - possibly bug

[Naveed Massjouni]

On Tue, Nov 15, 2011 at 3:52 AM, Stephen Fenwick-Paul
<stephen at activeg.org> wrote:
> Hi,
> I'm moving to plackup because of the well know contamination problem under
> Dancer when running multiple apps with  Plack::Handler::Apache2.
> My app.psgi is basically a copy of the one in the documentation - ta for
> that.
> $ plackup  -s Starman --workers=10 -p 5000 -a app.psgi
> My apache cfg is basically
>  <VirtualHost *:80>
>
>         ServerName www.app.new
>         ServerAlias app.new
>         DocumentRoot /home/stephen/app
>         <Location />
>             SetHandler perl-script
>             PerlHandler Plack::Handler::Apache2
>             PerlSetVar psgi_app /home/stephen/app/bin/app.pl
>         </Location>
>
>     </VirtualHost>
> The route:
> ajax '/locations/box/:nelat/:swlat/:nelng/:swlng' => sub {
>     my ($locs) = Locations->new();
>     return $locs->search( { mode => 'box' } );
> };
> is used correctly by apache version, but starman gets:
> get '/locations/box/:nelat/:swlat/:nelng/:swlng' => sub {
>     set serializer => 'JSON';
>     my ($locs) = Locations->new();
>     return $locs->search( { mode => 'box' } );
> };
> It can not see the ajax route.
> Examining the starman version's request I see
> "ajax => 0"
>  because
> "headers => undef"
> and that is what Dancer::Request::is_ajax uses to determine whether the call
> is ajaxed or not.
> although the starman's version request does contain
>     x_requested_with => "XMLHttpRequest"
> but it is not within 'headers' so it is not seen by is_ajax.
>
> I made this change to Dancer::Request
>
> sub is_ajax {
>     my $self = shift;
>      return 1 if (defined $self->{x_requested_with} && (
> $self->{x_requested_with} eq "XMLHttpRequest") ); # new
>     return 0 unless defined $self->headers;
>     return 0 unless defined $self->header('X-Requested-With');
>     return 0 if $self->header('X-Requested-With') ne 'XMLHttpRequest';
>     return 1;
> }
> and it appears to work. Is this a sensible change?
>

Thanks, that seems reasonable. I had the same problem except with
plackup vs nginx. I got around it by replacing all of the:
  ajax '/foo' => sub { ... }
with:
  get '/ajax/foo' => sub { ... }

It took me a very long time to debug that. Hopefully your fix will
solve and save others time. Also, your fix could be slightly shorter:

return 1 if $self->{x_requested_with} and $self->{x_requested_with} eq
"XMLHttpRequest";

-Naveed