A Call to All Dancer2 Plugin Writers - Hacking Thy Fearful Symmetry

Hacking Thy Fearful Symmetry

Hacker, hacker coding bright

A Call to All Dancer2 Plugin Writers

created: October 12, 2015

Was original a message to the dancer-user mailing list. Reproduced here for the signal boost. And because, hey, why not?

Edit: added the points brought by Racke in a reply to the original mailing list message.

Underneath the surface, I've been toiling away at a new plugin system for Dancer2. This new system aims at fixing a few of the thorny issues of the current one, and add a wee bit of unicorn dust to the mix.

For plugin users, the changes are:

  • No change! The new plugins will be called the same way as the old ones -- it'll be transparent to you if a plugin is new gen or old gen. Isn't that music to your ears, or what?

  • No change! Plugins using the new system can work side-by-side with original plugins. It's all really transparent to you. Relax, we're taking care of everything.

For plugin writers, the changes are:

  • The new system inherit from Dancer2::Plugin2 (yes, I know, we just loooove that '2' digit around here...).

  • The new system is much more OO-based, which so far makes for cleaner, easier to write plugins.

  • The new system doesn't export the Dancer keywords into the plugin namespace. It removes a little bit of the sugar (you'll have to do $self->app->request instead of request() inside the plugin module), but it makes much more explicit what is the plugin class, and what is the plugin instance associated with an app.

  • Plugin can now use other plugins!

  • The list of plugin instances are also kept as an attribute in the app object, which makes introspection possible (a plugin, for example, can check if other plugin A is already loaded or not and do things in consequence).

  • Plugins based on Plugin2 cannot use plugins based on Plugin(1).

What do I want from you?

Before unleashing D2::P2, it needs to be tested. Racke already migrated two plugins to D2::P2. I would like for all of you to try to migrate your plugins, and report if it was a success, or if you uncovered some sore points.

How to do that? I'm glad you asked:

  1. clone and use the Dancer2 branch

  2. read the D2::P2 docs (perldoc lib/Dancer2/Plugin2)

  3. if docs are not sufficient, check examples (/t/plugins2-*) and the already-ported modules at bullet #5 below.

  4. report all problems, head-scratchers, suggestions, etc to the D2::P2 PR

  5. you ported the plugin and all works? Post your victory to the PR dicussion at #4, and add your plugin to the list. That's important, I'll set up a job to test any new tweaks on D2::P2 to all the converted modules)

And, of course, you have questions or anything, please feel free to hit me with'em.

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About the author

Yanick Champoux
Perl necrohacker , ACP writer, orchid lover. Slightly bonker all around.