Ten Things You Didn't Know Rails Could Do

Presenter: James Edward Gray II

Bio

James (@JEG2) has been a Rails programmer for about as long as it has been fashionable to be one and a Rubyist even longer than that. As you probably know from listening to him on the Ruby Rogues podcast, James loves to dig into how our community and code works.

Abstract

Rails is huge. Even if you have worked with it for a long time, it's unlikely that you have stumbled across everything yet.

Do you really know what all of the built-in Rake tasks do? Have you seen all of the methods ActiveSupport makes available to you? Are you aware of all the queries ActiveRecord is capable of?

In this talk, I'll dig into the extras of Rails and see if I can't turn up some features that you don't see all of the time, but that might just be handy to know about anyway. I'll make sure you come out of this able to impress your friends at the hackfest.

Notes

From @james_gary

TODO

From @benjaminoakes

TODO

From @danbernier

@jeg2 is known as "Mr. Ruby Rogue."

Uh-oh: it's now FORTY-TWO things.

1. Get a hug, every Friday

Interfaces: give Rails a hug

Run a rails app from a single file, under 20 lines.

Find TODOs: rake notes:todo rake notes:fixme rake notes:custom ANNOTATION=foo

TODO blah

foo stuff

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Sandbox your consolerails c --sandbox

Run Helper Methods in the Console

helper.time_ago_in_words(3.days)

Use non-webrick servers in dev

rails s thin

Custom configuration with Railties ActiveSupport::OrderedOptions.new

Database

Shorthand migrations:

rails g resource user name:index email:uniq token:string{6} bio:text string{6}: a lengith limit :index: adds an index :uniq: adds a unique index

Associations: rails g resource article user:references OR rails g resource article user:belongs_to

rake db:migrate:status - tell you whether a migration has been run

Import your CSV, with headers:true, header_convertions: symbol

Store CSV in your database, with load & ...dump?

Pluck fields out of the database.

User.select(:email).map(&:email) -> User.pluck(:email)

Count records in groups Event.group(:trigger).count: group them, & count 'em up

Let you override associations belongs_to :previous_owner, class_name: "Owner"

Instantiate Records w/o a database User.instantiate('id' => 1, 'email' => '[email protected]')

Use limitless strings in postgresql ...something like, :delete_limit?

Use Full Text Search in Postgresql

rails g resource article subject bodi:text Use "tsvector" type in your migration Uses a generic inverted index plainto_tsquery('english', ?) -- postgres function for queriing it It does stemming for you.

Use a different database for each user. You end up having to connect to it in each controller action, so you're hitting the right database for each request.

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Why do this?

• To give us new ideas
• It's fun!

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Ruby Extensions

Updating Ruby's fashion sense

Atomic file writes File.atomic_write { |f| f.puts 'um' }

Merge nested hashes Hash#deep_merge

Remove specific Keys from a Hash Hash#except(:key1, :key2)

Add defaults to a Hash Hash#reverse_merge

Answer questions about strings "magic".inquiry.magic? #-> true

Views

Hide comments from your users with <%# ERb comments %>

Use a shorter ERb syntax % if current_user.try(:admin?) <%= render "edit_links" %> % end ...but you have to include PercentLineEnhancer into Erubis. The whole line has to be ruby, and it's all removed from the output.

Use blocks to avoid assignment in views. Write helper methods to a) do your math for you, and b) yield the value to a block. Delimits the scope of the variable. (You can also use #tap.)

Generate multiple tags at once. content_tag_for(:div, @article) now operates on collections.

Render any object: class MyModel def to_partial_path "not_my_normal_model_path" end end render :partial as ('as' is the important bit)

Group menu entrieswith grouped_options_for_select

Subclass ActiovView::Helpers::FormBuilder, and then... f.labeled_text_field_with_errors :my_attribute (You have to add these methods.)

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@tenderlove has a THEME SONG???

Route Exceptions the rails router is a rack application, so then: match "/404"...

Route to Sinatra (for APIs) ...and he gave some kind of authorization example that I kind of missed.

Stream CSV to users with format.csv, and headers['Content-Dispostion']

Do some work in the background require 'thread' @thread ||= THread.new do while job = queue.pop job.call end end ...(rest of the example) But you can queue up just a plain old lambda. That's pretty nice.

Publish a static site using rails - cache everything, then he has a rake task that touches earch page on the site. (This one included to ensure EVERYONE learned something from the talk.)

Slides are coming online. TODO ping him, since I missed the URL.

External Links

• Some related website