# Rails 3: Engines or/and Railties. How to use them? **URL:** \ **Category:** Rails\ **Created:** [September 24, 2010, 11:38pm UTC](https://www.ruby-forum.com/t/rails-3-engines-or-and-railties-how-to-use-them/195549 "2010-09-24T23:38:13Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![zeka](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/c6cbf5/32.png) [@zeka](https://www.ruby-forum.com/u/zeka)\ **Post date:** [September 24, 2010, 11:38pm UTC](https://www.ruby-forum.com/t/rails-3-engines-or-and-railties-how-to-use-them/195549/1 "2010-09-24T23:38:13Z")
Howdy all, I have spent a couple of days trying to figure out how to put different pieces of our (quite large) app into components. The idea was to use Rails 3 Engines/Railties and place them in /lib. Each would have its own [app/views, app/helpers, app/models and app/ controllers] We also needed an ability for those components to override views/ helpers/controllers in the parent “container app”. No luck there. Perhaps this snippet illustrates better what I was trying to do: [http://pastie.org/1180038](http://pastie.org/1180038) Is it what engines/railties are for? And if not, how can I “componentize” some of the partials we have? Our app needs certain pieces present/removed depending on which installation we do. Right now we have a bunch of if/elses that depend on configuration, and it looks a bit ugly, so I wanted to take some partials+controllers+models and move them into lib/xxx and then by including/excluding a single “require lib/xxx” I was planning to enable/disable them. Is it possible? Thank you ---
**Author:** ![zeka](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/c6cbf5/32.png) [@zeka](https://www.ruby-forum.com/u/zeka)\ **Post date:** [September 25, 2010, 8:00pm UTC](https://www.ruby-forum.com/t/rails-3-engines-or-and-railties-how-to-use-them/195549/2 "2010-09-25T20:00:13Z")
zeka wrote: > I have spent a couple of days trying to figure out how to put > different pieces of our (quite large) app into components. > > The idea was to use Rails 3 Engines/Railties and place them in /lib. > Each would have its own [app/views, app/helpers, app/models and app/ > controllers] > > We also needed an ability for those components to override views/ > helpers/controllers in the parent “container app”. > > No luck there. Perhaps this snippet illustrates better what I was > trying to do: [http://pastie.org/1180038](http://pastie.org/1180038) > > Is it what engines/railties are for? > And if not, how can I “componentize” some of the partials we have? > > Our app needs certain pieces present/removed depending on which > installation we do. Right now we have a bunch of if/elses that depend > on configuration, and it looks a bit ugly, so I wanted to take some > partials+controllers+models and move them into lib/xxx and then by > including/excluding a single “require lib/xxx” I was planning to > enable/disable them. This is a pretty big topic, and I haven’t found a good all-in-one resource either, but after a few days of poking around and re-reading articles, I’ve just started to componentize core libs I use in my apps as well. First, as for the path overrides, no need to inject paths yourself. Rails will look in certain places if you provide those places. You tried using /lib, but the correct place is in /vendor/plugins. Rails will look inside all /vendor/plugins/{WHATEVER}/app/views folders. So you were close. Don’t bother with the path shift business. Making a plugin is as simple as using the rails generator, but making engines requires a slightly different organization of the files. This is a good place to start, but there’s some out of date info. The /rails folder inside the plugin that the article suggests making is obsolete. > **[The Basics of Creating Rails Plugins — Ruby on Rails Guides](https://guides.rubyonrails.org/plugins.html#organize-your-files)** > > The Basics of Creating Rails PluginsA Rails plugin is either an extension or a modification of the core framework. Plugins provide: A way for developers to share bleeding-edge ideas without hurting the stable code base. A segmented architecture so... As for creating proper Rails3 engines, these are the links that I went round and round with until it started to make sense: > > > There are more than three files. show original [http://www.themodestrubyist.com/2010/03/01/rails-3-plugins---part-1---the-big-picture/](http://www.themodestrubyist.com/2010/03/01/rails-3-plugins---part-1---the-big-picture/) [http://www.themodestrubyist.com/2010/03/05/rails-3-plugins---part-2---writing-an-engine/](http://www.themodestrubyist.com/2010/03/05/rails-3-plugins---part-2---writing-an-engine/) > **[GitHub - krschacht/rails\_3\_engine\_demo: See the original post explaining this...](https://github.com/krschacht/rails_3_engine_demo)** > > See the original post explaining this demo here:. Contribute to krschacht/rails\_3\_engine\_demo development by creating an account on GitHub. After that you start making your engines and plugins into gem, and they become even easierto use in multiple projects. Hope that gives you a some help. – gw ---
**Author:** ![zeka](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/z/c6cbf5/32.png) [@zeka](https://www.ruby-forum.com/u/zeka)\ **Post date:** [September 27, 2010, 3:13am UTC](https://www.ruby-forum.com/t/rails-3-engines-or-and-railties-how-to-use-them/195549/3 "2010-09-27T03:13:02Z")
In addition to the resources that Greg mentioned, check out this too: [http://keithschacht.com/creating-a-rails-3-engine-plugin-gem/](http://keithschacht.com/creating-a-rails-3-engine-plugin-gem/) The one advantage I found of putting your shared resource into a plugin and storing in vendor/plugins is that while you’re editing the project it’s easy to peek into that directory to figure out what view you want to override. It’s really part of the same codebase whereas when it’s packaged in a gem, it’s usually a whole separate project (and separate repo) so it can be an extra step in your workflow to reference the resource’s code. But that advantage is also it’s disadvantage. By packaging your plugin into a full engine and packaging up as a gem, you get two advantages: gems are easier to share across projects, it’s easier to manage versions (you can specify the exact gem version you want in your gemfile), and they’re easier to distribute if you want to share them with others. -Keith zeka wrote: > Howdy all, > > I have spent a couple of days trying to figure out how to put > different pieces of our (quite large) app into components. > > The idea was to use Rails 3 Engines/Railties and place them in /lib. > Each would have its own [app/views, app/helpers, app/models and app/ > controllers] > > We also needed an ability for those components to override views/ > helpers/controllers in the parent “container app”. > > No luck there. Perhaps this snippet illustrates better what I was > trying to do: > [http://pastie.org/1180038](http://pastie.org/1180038) > > Is it what engines/railties are for? > And if not, how can I “componentize” some of the partials we have? > > Our app needs certain pieces present/removed depending on which > installation we do. Right now we have a bunch of if/elses that depend > on configuration, and it looks a bit ugly, so I wanted to take some > partials+controllers+models and move them into lib/xxx and then by > including/excluding a single “require lib/xxx” I was planning to > enable/disable them. > > Is it possible? > Thank you