Perl Dancer index.cgi for all requests - perl

I am trying to use the Perl Dancer module in my first application. The first application created a file called MyWeb-App/bin/app.pl which contains this code:
use Dancer;
use MyWeb::App;
dance;
and a file called MyWeb-App/lib/MyWeb/App.pm contains this code:
package MyWeb::App;
use Dancer ':syntax';
our $VERSION = '0.1';
get '/' => sub {
template 'index';
};
true;
I want one index.cgi file only to serve all my application requests. My question is,
do I have to put all my actions/methods in the same MyWeb-App/bin/app.pl file and a module
for each action/method like MyWeb-App/lib/MyWeb/App.pm module.
The reason is my application will contains hundreds of actions like this:
get 'register' => sub {...};
post 'save_register' => sub {...};
get 'contactus' => sub {...};
post 'save_contactus' => sub {...};
.....
get 'order' => sub {...};
post 'process_order' => sub {...};
So do I have to put all actions like that in one main index.cgi and I have to modify this file every time I add a new action or new module for the application.
In short, how to make application with large number of actions in modular way so each action in one module file for easy maintenance though other developers could add a separate modules to the application without overlapping/corrupting the main index.cgi.
In my regular none Framework application, I only load modules based on the route/action, so I load only one module per route per action with a simple logic like this:
if ($route eq "register") { eval "use register.pm"; register(); }
elsif ($route eq "save_register") { eval "use register.pm"; save_register(); }
....
....
elsif ($route eq "contactus") { eval "use contactus.pm"; contactus(); }

'index.cgi' is not used in Perl Dancer.
The framework intends for you to break up your application into a bunch of logical modules. Group them in a way that makes sense. For example, for a forum application with photos, you might have a "Users" module, a "Messages" module, and a "Photos" module.
In app.pl, you would have:
use Dancer;
use MyWeb::Users;
use MyWeb::Messages;
use MyWeb::Photos;
dance;
You would then create 3 different .pm files within ./lib, say users.pm, messages,pm, photos.pm, etc., and then include the relevant routes for each module. Your routes might begin with /user/, /message/, and /photo/*. For example, POST /user, GET /user, etc. Consider using the prefix function.
This should keep your project manageable, and your routes organized. As your project grows and you add more modules, you just modify app.pl and to include the new module (and routes).

Related

How to turn off caching in Mojolicious::Renderer [duplicate]

I'm currently developing a small single-page Web app using Mojolicious. The app has a Javascript frontend (using Backbone) that talks to a REST-ish API; the layout of the source is roughly:
use Mojolicious::Lite;
# ... setup code ...
get '/' => sub {
my $c = shift;
# fetch+stash data for bootstrapped collections...
$c->render('app_template');
};
get '/api_endpoint' => sub {
my $c = shift;
# fetch appropriate API data...
$c->render(json => $response);
};
# ... more API endpoints ...
app->start;
The app template uses EP, but very minimally; the only server-side template directives just insert JSON for bootstrapped collections. It's deployed via Apache as a plain CGI script. (This isn't optimal, but it's for low-traffic internal use, and more intricate server configuration is problematic in context.) Perl CGI is configured via mod_perl.
This works most of the time, but occasionally the renderer somehow gets the idea that it should cache the template and ignore changes to it. The debug records in error_log show "Rendering cached template" rather than the normal "Rendering template", and my new changes to the template stop appearing in the browser. I can't find a reliable way to stop this, though it will eventually stop on its own according to conditions I can't discern.
How can I make the app notice template changes reliably? Alternatively, how can I disable template caching completely?
How can I make the app notice template changes reliably?
This is what the morbo development server is for. Morbo wouldn't be used for your live code deployment, but for a development environment where you are continually changing your code and templates. Generally changes to live code and templates are meant to be handled by restarting the application server, or Apache in your case. (Hypnotoad has a hot-restart capability for this purpose)
Alternatively, how can I disable template caching completely?
To do this, add the following setup code (outside of routes, after use Mojolicious::Lite):
app->renderer->cache->max_keys(0);
For old answer see below.
I turned the findings of this answer into a plugin and released it on CPAN as Mojolicious::Plugin::Renderer::WithoutCache after discussing wit Grinnz on IRC, where they encouraged a release.
You can use it like this:
use Mojolicious::Lite;
plugin 'Renderer::WithoutCache';
It will create a new Cache object that does nothing, and install that globally into the renderer. That way, it doesn't need to be created every time like my initial answer below did.
In theory, this should be faster than Grinnz' approach (which is more sensible), and since you explicitly don't want to cache, you obviously want things to be as fast as possible, right? It's supposedly faster because the real Mojo::Cache would still need to go and try to set the cache, but then abort because there are no more free keys, and it also would try to look up the values from the cache every time.
I benchmarked this with both Dumbbench and Benchmark. Both of them showed negligible results. I ran them each a couple of times, but they fluctuated a lot, and it's not clear which one is faster. I included output of a run where my implementation was faster, but it still shows how minuscule the difference is.
Benchmark with Dumbbench:
use Dumbbench;
use Mojolicious::Renderer;
use Mojolicious::Controller;
use Mojolicious::Plugin::Renderer::WithoutCache::Cache;
my $controller = Mojolicious::Controller->new;
my $renderer_zero_keys = Mojolicious::Renderer->new;
$renderer_zero_keys->cache->max_keys(0);
my $renderer_nocache = Mojolicious::Renderer->new;
$renderer_nocache->cache( Mojolicious::Plugin::Renderer::WithoutCache::Cache->new );
my $bench = Dumbbench->new(
target_rel_precision => 0.005,
initial_runs => 5000,
);
$bench->add_instances(
Dumbbench::Instance::PerlSub->new(
name => 'max_keys',
code => sub {
$renderer_zero_keys->render( $controller, { text => 'foobar' } );
}
),
Dumbbench::Instance::PerlSub->new(
name => 'WithoutCache',
code => sub {
$renderer_nocache->render( $controller, { text => 'foobar' } );
}
),
);
$bench->run;
$bench->report;
__END__
max_keys: Ran 8544 iterations (3335 outliers).
max_keys: Rounded run time per iteration: 5.19018e-06 +/- 4.1e-10 (0.0%)
WithoutCache: Ran 5512 iterations (341 outliers).
WithoutCache: Rounded run time per iteration: 5.0802e-06 +/- 5.6e-09 (0.1%)
Benchmark with Benchmark:
use Benchmark 'cmpthese';
use Mojolicious::Renderer;
use Mojolicious::Controller;
use Mojolicious::Plugin::Renderer::WithoutCache::Cache;
my $controller = Mojolicious::Controller->new;
my $renderer_zero_keys = Mojolicious::Renderer->new;
$renderer_zero_keys->cache->max_keys(0);
my $renderer_nocache = Mojolicious::Renderer->new;
$renderer_nocache->cache( Mojolicious::Plugin::Renderer::WithoutCache::Cache->new );
cmpthese(
-5,
{
'max_keys' => sub {
$renderer_zero_keys->render( $controller, { text => 'foobar' } );
},
'WithoutCache' => sub {
$renderer_nocache->render( $controller, { text => 'foobar' } );
},
}
);
__END__
Rate max_keys WithoutCache
max_keys 190934/s -- -2%
WithoutCache 193846/s 2% --
I recon in a heavy load environment with lots of calls it would eventually make a difference, but that is very hard to prove. So if you don't like to think about the internals of the cache, this plugin might be useful.
Old answer:
Looking at Mojolicious::Plugin::EPRenderer I found out that there is a cache. It's a Mojo::Cache instance, which has the methods get, set and max_keys, and inherits from Mojo::Base (like probably everything in Mojolicious).
The ::EPRenderer gets a $renderer, which is a Mojolicious::Renderer. It holds the Mojo::Cache instance. I looked at $c with Data::Printer, and found out that there is a $c->app that holds all of those.
Knowing this, you can easily make your own cache class that does nothing.
package Renderer::NoCache;
use Mojo::Base -base;
sub get {}
sub set {}
sub max_keys {}
Now you stick it into $c.
package Foo;
use Mojolicious::Lite;
get '/' => sub {
my $c = shift;
$c->app->renderer->cache( Renderer::NoCache->new );
$c->render(template => 'foo', name => 'World');
};
app->start;
__DATA__
## foo.html.ep
Hello <%= $name =%>.
Now every attempt to get or set the cache simply does nothing. It will try caching, but it will never find anything.
Of course it's not great to make a new object every time. It would be better to make that object once at startup and get it into the internal permanent version of app. You have CGI, so it might not make a difference.
You could also just monkey-patch the get out of Mojo::Cache. This more hacky approach will do the same thing:
package Foo;
use Mojolicious::Lite;
*Mojo::Cache::get = sub { };
get '/' => sub {
my $c = shift;
$c->render(template => 'foo', name => 'World');
};
app->start;
But beware: we just disabled fetching from every cache in your application that uses Mojo::Cache. This might not be what you want.

Accessing subs from a require'd perl script

I'm going to import some perl code with the require statement. The code I'd like to import is in mylibA.pl:
#!/usr/bin/perl
package FOO::BAR;
sub routine {
print "A message!\n";
}
and mylibB.pl:
#!/usr/bin/perl
package FOO::BAZ;
sub routine {
print "Another message!\n";
}
Then I'm going to use it like this:
#!/usr/bin/perl
foreach my $lib (qw/ mylibA.pl mylibB.pl /){
require $lib;
print "Make a call to ${lib}'s &routine!\n";
}
Is there a way for my script to figure out the namespace that was pulled in with the require statement?
Wow. I have to say this is the one of the most interesting Perl questions I've seen in a while. On the surface this seems like a very simple request - get an included module's namespace, but there really is no way to do this. You can get it while in the package, but not from outside the package. I tried using EXPORT to send the local package name back to the caller script but that ended up going nowhere given the difference in how "use" and "require" work. A more module type of approach probably would have worked with a "use" statement, but the requirement that the required script be able to run by themselves prevented that approach. The only thing left to do was to directly pollute the caller's namespace and hope for the best (assume that the caller had no package namespace) - something that modules are designed to prevent.
BTW - I can't believe this actually works - in strict mode, no less.
caller.pl
#!/usr/bin/perl
use strict;
#package SomePackageName; #if you enable this then this will fail to work
our $ExportedPackageName;
print "Current package=".__PACKAGE__."\n";
foreach my $lib (qw/ mylibA.pl mylibB.pl /){
require $lib;
print "Make a call to ${lib}'s &routine!\n";
print "Package name exported=".$ExportedPackageName."\n";
$ExportedPackageName->routine;
} #end foreach
print "Normal Exit";
exit;
__END__
mylibA.pl
#!/usr/bin/perl
package FOO::BAR;
use strict;
#better hope the caller does not have a package namespace
$main::ExportedPackageName=__PACKAGE__;
sub routine {
print "A message from ".__PACKAGE__."!\n";
}
1;
mylibB.pl
#!/usr/bin/perl
package FOO::BAZ;
use strict;
#better hope the caller does not have a package namespace
$main::ExportedPackageName=__PACKAGE__;
sub routine {
print "Another message, this time from ".__PACKAGE__."!\n";
}
1;
Result:
c:\Perl>
c:\Perl>perl caller.pl
Current package=main
Make a call to mylibA.pl's &routine!
Package name exported=FOO::BAR
A message from FOO::BAR!
Make a call to mylibB.pl's &routine!
Package name exported=FOO::BAZ
Another message, this time from FOO::BAZ!
Normal Exit
Regarding the mostly academical problem of finding the package(s) in a perl source file:
You can try the CPAN module Module::Extract::Namespaces to get all packages within a perl file. It is using PPI and is thus not 100% perfect, but most of the time good enough:
perl -MModule::Extract::Namespaces -e 'warn join ",", Module::Extract::Namespaces->from_file(shift)' /path/to/foo.pm
But PPI can be slow for large files.
You can try to compare the active packages before and after the require. This is also not perfect, because if your perl library file loads additional modules then you cannot tell which is the package of the prinicipal file and what's loaded later. To get the list of packages you can use for example Devel::Symdump. Here's a sample script:
use Devel::Symdump;
my %before = map { ($_,1) } Devel::Symdump->rnew->packages;
require "/path/to/foo.pm";
my %after = map { ($_,1) } Devel::Symdump->rnew->packages;
delete $after{$_} for keys %before;
print join(",", keys %after), "\n";
You can also just parse the perl file for "package" declarations. Actually, that's what the PAUSE upload daemon is doing, so it's probably "good enough" for most cases. Look at the subroutine packages_per_pmfile in
https://github.com/andk/pause/blob/master/lib/PAUSE/pmfile.pm
There are two problems here:
How do I change the behaviour of a script when executed as a standalone and when used as a module?
How do I discover the package name of a piece of code I just compiled?
The general answer to question 2 is: You don't, as any compilation unit may contain an arbitrary number of packages.
Anyway, here are three possible solutions:
Name your modules so that you already know the name when you load it.
Have each module register itself at a central rendezvous point.
Like #1, but adds autodiscovery of your plugins.
The simplest solution is to put all of the API in an ordinary module, and put the standalone logic in a seperate script:
/the/location/
Module/
A.pm
B.pm
a-standalone.pl
b-standalone.pl
Where each standalone basically looks like
use Module::A;
Module::A->run();
If another script wants to reuse that code, it does
use lib "/the/location";
use Module::A;
...
If the loading happens on runtime, then Module::Runtime helps here:
use Module::Runtime 'use_module';
use lib "/the/location";
my $mod_a = use_module('Module::A');
$mod_a->run();
It isn't strictly necessary to place the contents of a-standalone.pl and Module/A.pm into separate files, although that is clearer. If you want to conditionally run code in a module only if it is used as a script, you can utilize the unless(caller) trick.
Of course all of this is tricksing: Here we determine the file name from the module name, not the other way round – which as I already mentioned we cannot do.
What we can do is have each module register itself at a certain predefined location, e.g. by
Rendezvous::Point->register(__FILE__ => __PACKAGE__);
Of course the standalone version has to shield against the possibility that there is no Rendezvous::Point, therefore:
if (my $register = Rendezvous::Point->can("register")) {
$register->(__FILE__ => __PACKAGE__);
}
Eh, this is silly and violates DRY. So let's create a Rendezvous::Point module that takes care of this:
In /the/location/Rendezvous/Point.pm:
package Rendezvous::Point;
use strict; use warnings;
my %modules_by_filename;
sub get {
my ($class, $name) = #_;
$modules_by_filename{$name};
}
sub register {
my ($file, $package) = #_;
$modules_by_filename{$file} = $package;
}
sub import {
my ($class) = #_;
$class->register(caller());
}
Now, use Rendezvous::Point; registers the calling package, and the module name can be retrived by the absolute path.
The script that wants to use the various modules now does:
use "/the/location";
use Rendezvous::Point (); # avoid registering ourself
my $prefix = "/the/location";
for my $filename (map "$prefix/$_", qw(Module/A.pm Module/B.pm)) {
require $filename;
my $module = Rendezvous::Point->get($filename)
// die "$filename didn't register itself at the Rendezvous::Point";
$module->run();
}
Then there are fully featured plugin systems like Module::Pluggable. This system works by looking at all paths were Perl modules may reside, and loads them if they have a certain prefix. A solution with that would look like:
/the/location/
MyClass.pm
MyClass/
Plugin/
A.pm
B.pm
a-standalone.pl
b-standalone.pl
Everything is just like with the first solution: Standalone scripts look like
use lib "/the/location/";
use MyClass::Plugin::A;
MyClass::Plugin::A->run;
But MyClass.pm looks like:
package MyClass;
use Module::Pluggable require => 1; # we can now query plugins like MyClass->plugins
sub run {
# Woo, magic! Works with inner packages as well!
for my $plugin (MyClass->plugins) {
$plugin->run();
}
}
Of course, this still requires a specific naming scheme, but it auto-discovers possible plugins.
As mentioned before it is not possible to look up the namespace of a 'required' package without extra I/O, guessing or assuming.
Like Rick said before, one have to intrude the namespace of the caller or better 'main'. I prefer to inject specific hooks within a BEGIN block of the 'required' package.
#VENDOR/App/SocketServer/Protocol/NTP.pm
package VENDOR::App::SocketServer::Protocol::NTP;
BEGIN {
no warnings;
*main::HANDLE_REQUEST = \&HANDLE_REQUEST;
}
sub HANDLE_REQUEST {
}
#VENDOR/App/SocketServer.pm
my $userPackage= $ARGV[0];
require $userPackage;
main::HANDLE_REQUEST();
Instead of *main:: you can get more specific with *main::HOOKS::HANDLE_REQUESTS i.e. This enables you to resolve all injected hooks easily within the caller by iterating over the HOOK's namespace portion.
foreach my $hooks( keys %main::HOOKS ) {
}

In Perl, can I dynamically add methods to only one object of a package?

I'm working with WWW::Mechanize to automate web-based back office clicking I need to do to get my test e-commerce orders into the state I need them to be to test changes I have made to a particular part of a long, multi-part workflow. To process a lot of orders in a batch, I need to click the Home link often. To make that shorter, I hacked a method into WWW::Mechanize at run time like this (based on an example in Mastering Perl by brian d foy):
{ # Shortcut to go back to the home page by calling $mech->go_home
# I know I'll get a warning and do not want it!
no warnings 'once';
my $homeLink = $mech->find_link( text => 'Home' )->url_abs();
$homeLink =~ s/system=0/system=1/;
*WWW::Mechanize::go_home = sub {
my ($self) = #_;
return $self->get($homeLink);
};
}
This works great, and does not hurt anyone because the script I'm using it in is only used by me and is not part of the larger system.
But now I wonder if it is possible to actually only tell one $mech object that is has this method, while another WWW::Mechanize object that might be created later (to, say, do some cross-referencing without mixing up the other one that has an active session to my back office) cannot use that method.
I'm not sure if that is possible at all, since, if I understand the way objects work in Perl, the -> operator tells it to look for the subroutine go_home inside the package WWW::Mechanize and pass the $mech as the first argument to it. Please correct me if this understanding is wrong.
I've experimented by adding a sort of hard-coded check that only lets the original $mech object use the function.
my $onlyThisMechMayAccessThisMethod = "$mech";
my $homeLink = $mech->find_link( text => 'Home' )->url_abs();
$homeLink =~ s/system=0/system=1/;
*WWW::Mechanize::go_home = sub {
my ($self) = #_;
return undef unless $self eq $onlyThisMechMayAccessThisMethod;
return $self->get($homeLink);
};
Since "$mech" contains the address of where the data is stored (e.g. WWW::Mechanize=HASH(0x2fa25e8)), another object will look differently when stringified this way.
I am not convinced however that this is the way to go. So my question is: Is there a better way to only let one object of the WWW::Mechanize class have this method? I'm also glad about other suggestions regarding this code.
This is just
$mech->follow_link(text => 'Home')
and I don't think it's special enough to warrant a method of its own, or to need restricting to an exclusive club of objects.
It's also worth noting that there is no need to mess with typeglobs to declare a subroutine in a different package. You just have to write, for example
sub WWW::Mechanize::go_home {
my ($self) = #_;
return $self->get($homeLink);
};
But the general solution is to subclass WWW::Mechanize and declare as members only those objects you want to have the new method.
File MyMechanize.pm
package MyMechanize;
use strict;
use warnings;
use parent 'WWW::Mechanize';
sub go_home {
my $self = shift;
my $homeLink = $self->find_link(text => 'Home')->url_abs;
$homeLink =~ s/system=0/system=1/;
return $self->get($homeLink);
}
1;
File test.pl
use strict;
use warnings;
use MyMechanize;
my $mech = MyMechanize->new;
$mech->get('http://mydomain.com/path/to/site/page.html')
$mech->go_home;

Clash Between Multiple Locales in a mod_perl Setting?

I'm currently working on internationalizing a large Perl/Mason web application (Perl 5.8.0, Mason 1.48, mod_perl & Apache). In choosing a localization module, I decided to go with Locale::TextDomain over Locale::Maketext, mostly because the latter's plural form support isn't as nice as I'd like.
The hang-up I'm having with Locale::TextDomain is that it resolves which catalog to use for translations based on the process' locale. When I realized this, I got worried about how this would affect my application if I wanted users to be able to use different locales -- would it be possible that a change in locale to suit one user's settings would affect another user's session? For example, could there be a situation in which an English user received a page in German because a German user's session changed the process' locale? I'm not very knowledgeable about how Apache's thread/process model works, though it seems that if multiple users can be served by the same thread, this could happen.
This email thread would indicate that this is possible; here the OP describes the situation I'm thinking about.
If this is true, is there a way I can prevent this scenario while still using Locale::TextDomain? I suppose I could always hack at the module to load the catalogs in a locale-independent (probably using DBD::PO), but hopefully I'm just missing something that will solve my problem...
You entirely avoid the setlocale problems by using web_set_locale instead.
(That message on the mailing list predates the addition of that function by about 4 years.)
Edit: You are correct that global behaviour persists in Apache children, leading to buggy behaviour.
I wrote up a test case:
app.psgi
use 5.010;
use strictures;
use Foo::Bar qw(run);
my $app = sub {
my ($env) = #_;
run($env);
};
Foo/Bar.pm
package Foo::Bar;
use 5.010;
use strictures;
use Encode qw(encode);
use File::Basename qw(basename);
use Locale::TextDomain __PACKAGE__, '/tmp/Foo-Bar/share/locale';
use Locale::Util qw(web_set_locale);
use Plack::Request qw();
use Sub::Exporter -setup => { exports => [ 'run' ] };
our $DEFAULT_LANGUAGE = 'en'; # untranslated source strings
sub run {
my ($env) = #_;
my $req = Plack::Request->new($env);
web_set_locale($env->{HTTP_ACCEPT_LANGUAGE}, undef, undef, [
map { basename $_ } grep { -d } glob '/tmp/Foo-Bar/share/locale/*'
]); # XXX here
return $req
->new_response(
200,
['Content-Type' => 'text/plain; charset=UTF-8'],
[encode('UTF-8', __ 'Hello, world!')],
)->finalize;
}
The app runs as a PerlResponseHandler. When the user request a language that cannot be set, the call fails silently and the language that was used last successfully is still enabled.
The trick to fix this is to always set to a language that exists with a fallback mechanism. At the spot marked XXX, add the code or web_set_locale($DEFAULT_LANGUAGE), so that despite using a global setting, the behaviour cannot persist because we guarantee that it is set/changed once per request.
Edit 2: Further testing reveals that it's not thread-safe, sorry. Use the prefork MPM only which isolates requests as processes; however worker and event are affected because they are thread-based.

Perl module loading - Safeguarding against: perhaps you forgot to load "Bla"?

When you run perl -e "Bla->new", you get this well-known error:
Can't locate object method "new" via package "Bla"
(perhaps you forgot to load "Bla"?)
Happened in a Perl server process the other day due to an oversight of mine. There are multiple scripts, and most of them have the proper use statements in place. But there was one script that was doing Bla->new in sub blub at line 123 but missing a use Bla at the top, and when it was hit by a click without any of the other scripts using Bla having been loaded by the server process before, then bang!
Testing the script in isolation would be the obvious way to safeguard against this particular mistake, but alas the code is dependent upon a humungous environment. Do you know of another way to safeguard against this oversight?
Here's one example how PPI (despite its merits) is limited in its view on Perl:
use strict;
use HTTP::Request::Common;
my $req = GET 'http://www.example.com';
$req->headers->push_header( Bla => time );
my $au=Auweia->new;
__END__
PPI::Token::Symbol '$req'
PPI::Token::Operator '->'
PPI::Token::Word 'headers'
PPI::Token::Operator '->'
PPI::Token::Word 'push_header'
PPI::Token::Symbol '$au'
PPI::Token::Operator '='
PPI::Token::Word 'Auweia'
PPI::Token::Operator '->'
PPI::Token::Word 'new'
Setting the header and assigning the Auweia->new parse the same. So I'm not sure how you can build upon such a shaky foundation. I think the problem is that Auweia could also be a subroutine; perl.exe cannot tell until runtime.
Further Update
Okay, from #Schwern's instructive comments below I learnt that PPI is just a tokenizer, and you can build upon it if you accept its limitations.
Testing is the only answer worth the effort. If the code contains mistakes like forgetting to load a class, it probably contains other mistakes. Whatever the obstacles, make it testable. Otherwise you're patching a sieve.
That said, you have two options. You can use Class::Autouse which will try to load a module if it isn't already loaded. It's handy, but because it affects the entire process it can have unintended effects.
Or you can use PPI to scan your code and find all the class method calls. PPI::Dumper is very handy to understand how PPI sees Perl.
use strict;
use warnings;
use PPI;
use PPI::Dumper;
my $file = shift;
my $doc = PPI::Document->new($file);
# How PPI sees a class method call.
# PPI::Token::Word 'Class'
# PPI::Token::Operator '->'
# PPI::Token::Word 'method'
$doc->find( sub {
my($node, $class) = #_;
# First we want a word
return 0 unless $class->isa("PPI::Token::Word");
# It's not a class, it's actually a method call.
return 0 if $class->method_call;
my $class_name = $class->literal;
# Next to it is a -> operator
my $op = $class->snext_sibling or return 0;
return 0 unless $op->isa("PPI::Token::Operator") and $op->content eq '->';
# And then another word which PPI identifies as a method call.
my $method = $op->snext_sibling or return 0;
return 0 unless $method->isa("PPI::Token::Word") and $method->method_call;
my $method_name = $method->literal;
printf "$class->$method_name seen at %s line %d.\n", $file, $class->line_number;
});
You don't say what server enviroment you're running under, but from what you say it sounds like you could do with preloading all your modules in advance before executing any individual pages. Not only would this prevent the problems you're describing (where every script has to remember to load all the modules it uses) but it would also save you memory.
In pre-forking servers (as is commonly used with mod_perl and Apache) you really want to load as much of your code before your server forks for the first time so that the code is stored once in copy-on-write shared memory rather than mulitple times in each child process when it is loaded on demand.
For information on pre-loading in Apache, see the section of Practical mod_perl