SYNOPSIS
# in config.yml
plugins:
Adapter:
ua:
class: HTTP::Tiny
scope: request
options:
max_redirect: 3
# in your app
use Dancer2::Plugin::Adapter;
get '/proxy/:url' => sub {
my $res = service('ua')->get( params->{'url'} );
if ( $res->{success} ) {
return $res->{content};
}
else {
template 'error' => { response => $res };
}
};
DESCRIPTION
The problem: you want to use some perl class in your Dancer2 app, but
there's no plugin for it.
The solution: as long as the class needs only static data to construct
an object, then Dancer2::Plugin::Adaptor can do the wrapping for you.
Think of it as a "just-in-time" plugin (or maybe a poor-man's
Bread::Board).
Here's another example: you want to send emails via Postmark
<
http://postmarkapp.com> using WWW::Postmark.
In your config.yml, you put this:
plugins:
Adapter:
postmark:
class: WWW::Postmark
scope: singleton
options: POSTMARK_API_TEST
In your production config.yml, you can replace 'POSTMARK_API_TEST' with
your real Postmark API key.
Then, in your application, here's how you use it:
get '/' => sub {
eval {
service("postmark")->send(
from => '
[email protected]',
to => '
[email protected],
[email protected]',
subject => 'an email message',
body => "hi guys, what's up?"
);
};
return $@ ? "Error: $@" : "Mail sent";
};
Dancer2::Plugin::Adapter takes care of constructing and caching the
WWW::Postmark object based on the configuration data, and lets you
access the object with the service() function.
CONFIGURATION
One or more objects are defined by NAME => HASHREF pairs. The hash
reference for each NAME must contain a 'class' key, whose value is the
class to wrap.
The 'scope' key determines how long the generated object persists. The
choice of scope will depend on whether the object holds onto any state
that should not last across requests. The following scope values are
allowed:
request
(default) the object persists in the vars hash for the duration of
the request
singleton
the objects persists in a private, lexical hash for the duration of
the process
none
the object is not cached; a fresh object is created on each call
If the hash reference contains an 'options' key, its value will be
dereferenced (if it is a hash or array reference) and passed to new()
when the object is created. Note that if the class requires a reference
for the constructor, you have to wrap it in an extra array. E.g.
# config.yml:
plugins:
Adapter:
foo:
class: Foo::Bar
scope: request
options:
-
wibble: wobble
biff: boff
# constructor called as:
Foo::Bar->new( { wibble => wobble, biff => boff } );
If the class does not use 'new' as the name of its constructor, an
alternate can be specified with the 'constructor' key.
# config.yml:
plugins:
Adapter:
tmpdir:
class: File::Temp
constructor: newdir
# constructor called as:
File::Temp->newdir()
When caching under request scope, Dancer2::Plugin::Adaptor uses the key
_dpa in the vars.
USAGE
service
$object = service($name);
This function returns the object corresponding to the name defined in
the configuration file. The object is created on demand and may be
cached for future use based on its scope configuration option.
SEE ALSO
Dancer2
Dancer2::Plugin
ACKNOWLEDGMENTS
Thank you to Matt S. Trout for suggesting the 'scope' controls.
