Rails Engines - All Site Updates

Frequently Asked Questions

Wed, 30 Aug 2006 06:13:38 GMT

Engines vs Generators

Engines could be considered in many ways the natural successor to Rails' generators:

Both are mechanisms for packaging up disparate groups of files which must be placed throughout your whole application directory structure
Both provide controllers, models, libraries and views, along with schema information, tests and helpers to be used throughout your application's code.

Oh God, What Have We Done?

This was something of a response to misunderstandings about what Engines are. For more background you might want to read DHH's first post about engines and this.

Issue Tracker Login Information

I hate spam, and no more so that on issue tracking websites. To log into http://dev.rails-engines.org and comment or create new tickets, you need to login:

  login: engines
  password: engines

You can login in here.

Development

Wed, 30 Aug 2006 06:11:07 GMT

Read the README!

If you're interested in developing plugins that ultilise the engines plugin, the first thing you need to read is the engines plugin README, which lays down all the basics about how it enhances Rails' own plugin mechanism.

Tutorials

Gwyn Morfey has written a guide building plugins that can take advantage of the engines plugin's features.

Joe at AlterLabs also wrote one of the best introductions to developing an engine (thought this has not been updated to reflect the 1.2 release of the engines plugin yet).

Other Information

Introduction

Wed, 30 Aug 2006 04:49:24 GMT

The engines plugin? Huh?

The engines plugin enhances Rails' own plugin framework, making it simple to share controllers, helpers, models, public assets, routes and migrations in plugins.

It enables plugins to carry whole chunks of functionality into your existing application without affecting any of your existing code. They could also be described as application aspects, or vertical application slices - top-to-bottom units which provide full MVC coverage for a certain, specific application function.

Alternatively, you can use the engines plugin to share the smallest, simplest assets including common migrations, javascripts, stylesheets or images.

See the engines plugin in action

~~In true Rails style, we've got a demo video (Quicktime, 13MB) all pipin'-hot and ready to serve ya!~~ This video refers to an old version of the engines plugin; I hope to upload an updated one soon, highlighting many of the new features. It's also work noting that it demonstrates the login engine, which has now been deprecated.

If you don't like video, then head straight over to the engines plugin README.

Installation

See the Download page for info on setting up the main Engines plugin.

More Information

More information can be found all over this site, but in particular you might want to check out the Frequently Asked Questions and the Developer documentation.

Bugs and Issues

Wed, 30 Aug 2006 04:42:54 GMT

If you're having problems with engines, there are quite a few places to look for help:

Our Lighthouse page
- Open Tickets
The mailing lists:
- If you're having problems with a specific engine, please post to the engine-users mailing list;
- Discussion of the engines plugin internals and bug reports go to engine-developers.
The rails mailing list itself: rubyonrails-talk@googlegroups.com

Download

Wed, 30 Aug 2006 04:16:56 GMT

There are quite a few ways to get your hands on the various engines available. The first thing to do in any case is to get the Engines plugin itself, which is what we'll cover here.

Rails' own `script/plugin` command

The first thing to do is update the plugin command's list of download sources:

  $ ruby script/plugin discover

Now we can install the actual Engines plugin:

  $ ruby script/plugin install engines

Alternately, you can explicitly specify the location from which to download and install the engines plugin:

  $ ruby script/plugin install http://svn.rails-engines.org/plugins/engines

From this point you can now install plugins as normal - any additional files each plugin provides will automatically become available when your Rails application loads.

SVN

Developers using SVN will probably find it much more convenient to use SVN itself to include engines (and plugins) in their applications. The Rails Engines repository can currently be found at http://svn.rails-engines.org/. The layout for this repository is discussed here.

SVN Externals

SVN externals are an ideal way of including code from other repositories in your own application. The basic commands for including the Engines plugin into your plugins directory via SVN externals are:

  $ cd PATH_TO_YOUR_APP
  $ svn propset svn:externals "engines http://svn.rails-engines.org/engines/tags/rel_1.2.0" vendor/plugins

It is highly recommended that you use tags if you are deploying business-critical applications, since there is some chance that any changes to the trunk or any subsequent releases will negatively affect your application. Alternatively, you could use the Piston tool.

For more information run:

  $ svn help propset

News

Wed, 30 Aug 2006 03:15:29 GMT

Heading for Github

I've been using Git for a few months now, so I'm happy to say that the engines plugin development is going to be heading over to GitHub in the near future.

Posted by James Adam on Apr 28, 2008

Engines 2.0 (ish)

Hi all,

Just a quick note to let you know, should it be relevant, that we're readied a new release of the Engines plugin, revamped and ready for Rails 2.0, and would absolutely love for you to start using it and sending feedback about what's broken, what's missing and what could be improved.

Grab the plugin here, check out the README, and find out more after the cut...

Posted by James Adam on Dec 11, 2007

Plugems, Welcome!

Revolution on Rails have finally released their solution to shared dependencies between Rails applications, which they have called Plugems (see what they've done there?). In their announcement they discuss some of the differences between plugins, "engines" (ahem!) and Plugems, and I think they've raised some interesting points.

Posted by James Adam on May 02, 2007

Engines 1.2 Released

I've just pushed the 1.2 release of the engines plugin forward as the official release found by script/plugin. The 1.2 release is compatible with Rails 1.2, and undoubtedly the best release so far. It's never been easier to make your plugins more powerful, and I'm very happy with some of the new features 1.2 gives, including routes in plugins and a new "best-practise" for sharing migrations.

Engines are dead...

The new 1.2 release also represents a psychological "reboot" for the engines plugin. Thanks to some of the features we managed to contribute to Rails itself, any plugin can be enhanced by the engines plugin. This is the final blow to the unfortunate misunderstanding that "engines are evil", because there's literally no such thing as "an engine" anymore. The engines plugin is just a plugin that makes other plugins more powerful.

Below the cut you can read about some of the enhancements that the engines plugin contributes to making sharing code amongst your projects even simpler.

Posted by James Adam on Feb 04, 2007

Farewell, login_engine.

While I prepare for the upcoming release of the engines plugin 1.2 release, I should also add that the "login engine" and "user engine" won't be joining us on the journey to 1.2.

Posted by James Adam on Jan 23, 2007

Rails Engines - All Site Updates

Frequently Asked Questions

Development

Read the README!

Tutorials

Other Information

Introduction

The engines plugin? Huh?

See the engines plugin in action

Installation

More Information

Bugs and Issues

Download

Rails' own script/plugin command

SVN

SVN Externals

News

Engines are dead...

Rails' own `script/plugin` command