NAME¶
Dancer::ModuleLoader - dynamic module loading helpers for Dancer core components
SYNOPSIS¶
Taken directly from Dancer::Template::TemplateToolkit (which is core):
die "Template is needed by Dancer::Template::TemplateToolkit"
unless Dancer::ModuleLoader->load('Template');
# we now have Template loaded
DESCRIPTION¶
Sometimes in Dancer core we need to use modules, but we don't want to declare
them all in advance in compile-time. These could be because the specific
modules provide extra features which depend on code that isn't (and shouldn't)
be in core, or perhaps because we only want these components loaded in lazy
style, saving loading time a bit. For example, why load Template (which isn't
required by Dancer) when you don't use Dancer::Template::TemplateToolkit?
To do such things takes a bit of code for localizing $@ and "eval"ing.
That code has been refactored into this module to help Dancer core developers.
Please only use this for Dancer core modules. If you're writing an
external Dancer module (Dancer::Template::Tiny, Dancer::Session::Cookie,
etc.), please simply ""use ModuleYouNeed"" in your code
and don't use this module.
METHODS/SUBROUTINES¶
load¶
Runs a ""use ModuleYouNeed"".
use Dancer::ModuleLoader;
...
Dancer::ModuleLoader->load('Something')
or die "Couldn't load Something\n";
# load version 5.0 or more
Dancer::ModuleLoader->load('Something', '5.0')
or die "Couldn't load Something\n";
# load version 5.0 or more
my ($res, $error) = Dancer::ModuleLoader->load('Something', '5.0');
$res or die "Couldn't load Something : '$error'\n";
Takes in arguments the module name, and optionally the minimum version number
required.
In scalar context, returns 1 if successful, 0 if not. In list context, returns 1
if successful, "(0, "error message")" if not.
If you need to give argumentto the loading module, please use the method
"load_with_params"
require¶
Runs a ""require ModuleYouNeed"".
use Dancer::ModuleLoader;
...
Dancer::ModuleLoader->require('Something')
or die "Couldn't require Something\n";
my ($res, $error) = Dancer::ModuleLoader->require('Something');
$res or die "Couldn't require Something : '$error'\n";
If you are unsure what you need ("require" or "load"), learn
the differences between "require" and "use".
Takes in arguments the module name.
In scalar context, returns 1 if successful, 0 if not. In list context, returns 1
if successful, "(0, "error message")" if not.
load_with_params¶
Runs a ""use ModuleYouNeed qw(param1 param2 ...)"".
use Dancer::ModuleLoader;
...
Dancer::ModuleLoader->load('Something', qw(param1 param2) )
or die "Couldn't load Something\n";
my ($res, $error) = Dancer::ModuleLoader->load('Something', @params);
$res or die "Couldn't load Something : '$error'\n";
Takes in arguments the module name, and optionally parameters to pass to the
import internal method.
In scalar context, returns 1 if successful, 0 if not. In list context, returns 1
if successful, "(0, "error message")" if not.
use_lib¶
Runs a ""use lib qw(path1 path2)"" at run time instead of
compile time.
use Dancer::ModuleLoader;
...
Dancer::ModuleLoader->use_lib('path1', @other_paths)
or die "Couldn't perform use lib\n";
my ($res, $error) = Dancer::ModuleLoader->use_lib('path1', @other_paths);
$res or die "Couldn't perform use lib : '$error'\n";
Takes in arguments a list of path to be prepended to @INC, in a similar way than
"use lib". However, this is performed at run time, so the list of
paths can be generated and dynamic.
In scalar context, returns 1 if successful, 0 if not. In list context, returns 1
if successful, "(0, "error message")" if not.
class_from_setting¶
Given a setting in Dancer::Config, composes the class it should be.
This is the function that translates:
# in config.yaml
template: "template_toolkit"
To the class:
Dancer::Template::TemplateToolkit
Example:
use Dancer::ModuleLoader;
my $class = Dancer::ModuleLoader->class_from_setting(
'Dancer::Template' => 'template_toolkit',
);
# $class == 'Dancer::Template::TemplateToolkit
$class = Dancer::ModuleLoader->class_from_setting(
'Dancer::Template' => 'tiny',
);
# class == 'Dancer::Template::Tiny
AUTHOR¶
Alexis Sukrieh
LICENSE AND COPYRIGHT¶
Copyright 2009-2010 Alexis Sukrieh.
This program is free software; you can redistribute it and/or modify it under
the terms of either: the GNU General Public License as published by the Free
Software Foundation; or the Artistic License.
See
http://dev.perl.org/licenses/ for more information.