Useful Rails Stuff

Rails Generate

References

Add a charity_id index to the Candidate model (Candidate belongs to Charity)

bundle exec rails generate migration add_charity_to_candidate charity:references

bundle exec rails generate scaffold Branch charity:references name:string description:string url:string country:string country_region:string city:string phone_number:string

Scaffold with Polymorphic

rails generate scaffold need_tag name:string tagable:references{polymorphic}

Setup a new Rails app with Tests

I don’t need to do this very often, so when I do there is always something I need to look up. So time to make some notes…

cd ~/projects/

I already have rails installed, if you don’t you’ll need to get it installed. There are some notes on this site that cover getting an Ubuntu or Mac set up that may help.

rails new example

cd example

Next you need to add rspec-rails to your Gemfile (in the :development and :test groups). You can do this the easy but fractionally more laborious way by adding gem 'rspec-rails' to your Gemfile, or by using this super-cool line (courtesy of the relishapp.com help files): echo "gem 'rspec-rails', :group => [:development, :test]" >> Gemfile

Manually adding gem 'rspec-rails' to your Gemfile will result in a slightly neater Gemfile

bundle

rails generate rspec:install

Now to add something to your new site to test. Lets say, for example, you want to keep a record of given/long URL’s and corresponding generated/short URL’s, you may do something like rails generate scaffold Url long_url:string short_url:string.

I prefer HAML to ERB view files, so I did this (skip these steps if you are happy with ERB)

If you ran the rails generate above you can undo it like this rails destroy scaffold Url long_url:string short_url:string

Add gem 'haml' and gem 'haml-rails' to your Gemfile

bundle

rails generate scaffold Url long_url:string short_url:string

You get nice HAML view files

rake db:migrate && rake db:test:prepare

rspec

The tests should pass, with some pending tests. Congratulations, you have now set up rails with tests and can go ahead and get all tests working and/or add new functionality (as shown below)

Get the skipped/pending tests working

Valid URLs

Replace skip("Add a hash of attributes valid for your model") with something like {long_url: 'http://www.mysite.com/some-kind-of-page.html', short_url: 'http://me.co/hrt12'} in urls_controller_spec.rb to get most of the pending tests passing (as you can see by running rspec again).

Invalid URLs

Replace skip("Add a hash of attributes invalid for your model") with something like {long_urls: 'not a valid long url', short_url: 'not a valid short url'} and run rspec again.

We get some errors. The top errors can be fixed by adding validation to the Url model. We should not allow invalid URL’s, so lets try validates_format_of :long_url, :short_url, :with => URI::regexp(%w(http https)).

Running rspec shows fewer erros, all of which are from view specs/tests. Replace entries like :long_url => "MyString" (which are not valid according to the validation we just added) with something like :long_url => 'http://www.mysite.com/some-kind-of-page.html'.

Do rspec again and all tests are passing again, but we still have 3 pending. One of them is easily fixed following the same route as above and the last two are for UrlsHelper which is not yet implemented.

Congratulations, you have now set up rails with working tests and can go ahead and add new functionality.

Add new functionality

I’d like to generate short URL’s based on the user supplied long URL’s (rather than asking the user to supply both). To do this we first need to update our tests… (I’ve run out of time for now, so the rest of these notes are pending)