This is an excellent tip to know, for me at-least, as I get back into the mix of using Rails for Web Development. Recently, I just purchased Agile Web Development with Rails 2nd ed., and plan on reading the whole book front to back. Yes, that’s right! Front-to-back. I purchased the first edition last year, but got halfway through, only to be distracted by administering *Nix and Windows! 😦
Anyway, having a local copy of the Rails API Documentation is very valuable, especially when you are on the road and there is no Internet! It took me 5 minutes and 36 seconds to create my own rails API locally.
1. Create a fake rails application directory — RailsDoc
swinful@thinkpad> cd Desktop
swinful@thinkpad> rails RailsDoc
create
create app/controllers
create app/helpers
create app/models
create app/views/layouts
…edited…
create log/server.log
create log/production.log
create log/development.log
create log/test.log
2. Freeze the application — RailsDoc
swinful@thinkpad> cd RailsDoc/
swinful@thinkpad> rake rails:freeze:gems
(in /usr/home/swinful/Desktop/RailsDoc)
Freezing to the gems for Rails 1.2.2
rm -rf vendor/rails
mkdir -p vendor/rails
cd vendor/rails
…edited…
The freeze command will essentially make it possible to use the version of rails and gems that were used while the application was being developed, but at a later time. The next step will take the most time:)
3. Rake, one last time — RailsDoc
swinful@thinkpad> echo >! vendor/rails/activesupport/README
swinful@thinkpad> rake doc:rails
(in /usr/home/swinful/Desktop/RailsDoc)
rm -r doc/apiREADME:
CHANGELOG:
…edited…
xmlmarkup.rb: mc………….
Generating HTML…Files: 263
Classes: 417
Modules: 525
Methods: 1933
Elapsed: 337.176s
69.724u 45.620s 5:37.66 34.1% 5+57932k 67+8io 3pf+0w
In the RailsDoc folder, move doc/api to another directory.
swinful@thinkpad> mv doc/api ~/Desktop/RailsApi
That’s all.
Well-Rounded 
Really thanks for your awesome method. There is no local rdoc for rails through gem_server on my ubuntu box. I don’t know why.
Very useful, thanks !
Thanks, it helps especially when rubyonrails.org was down.
Hi Julien, I am glad to hear you found this posting useful.
Regards,
swinful
Hahaha =D
All you need is to copy the “doc” folder with all these htmls from rubygems directory to your desktop (or create a link).
On openSUSE they are located in /usr/lib/ruby/gems/1.8/doc/rails-2.3.8/
@Andrew: Some linux distros may already have the local copy of the API Documentation as you point out with openSUSE. But for those that do not, knowing how to generate the docs, especially when no internet access is available, can come in handy. -:)
Thank you for sharing your shortcut. -:)
Regards,
swinful
@swinful
No =)
No matter which distro u are using, rubygem content should not vary unless you are using something really very exotic (do u?=)).
Most distros don’t include recent rails at all, but it is ok, because the standard way to install rails is rubygems (gem install rails or gem1.8 install rails). Docs will be in the *somefolder*/lib/ruby/gems/1.8/doc/rails-*version*.
You can find out where your gems are located with ‘gem (or gem1.8) help install’, somewhere at the end of the help message.
And if you prefer APT (in case u are an Ubuntu fan=), it should still install the same files as with gems. But remember the version in Ubuntu repos is outdated. openSUSE is the only distro I know which ships recent versions of popular rubygems through the SUSE’s packaging system.
Your solution is still useful because it points at how to create local copy of Rails Guides =)
BTW, rake doc:guides 😉
and, sorry for my english. 99,9% of my time i speak russian.
Well, you were right, api docs are not included with rails gem. I’m sorry. Rails is the only gem I know with empty docs folder.
But you can still use my solution to read specs for any other gem.