Rails Is from Mars, Ruby Is from Venus

8/14/2019 Rails Is from Mars, Ruby Is from Venus

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WHO AM I?

My name is Rein Henrichs.

Thats pronounced like rain.

But spelled differently.

I work at

I blog at reinh.com

I twitter @reinh

I like candlelit dinners and long walks on the beach.
https://twitter.com/home?status=@ReinHhttp://reinh.com/https://twitter.com/home?status=@ReinHhttp://reinh.com/http://reinh.com/https://twitter.com/home?status=@ReinH


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YOU KNOW RAILS

insert logohere:(


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BUT DO YOU KNOW RUBY?


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How many people here use Rails?


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How many of you think you knowRuby as well as you know Rails?


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How many of you have

contributed to an open-sourceRuby project?


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How many of you havewritten your own gem?


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How many of you would be

comfortable writing an HTTPclient library in Ruby?


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How many of you could writeyour own web framework?


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WHY SHOULD I LEARN RUBY?

Its easy.

Its fun.

It will make you better at Rails.

It will make you a better person.


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HOW DO I LEARN RUBY?Some resources


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Free stuff


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WHYS POIGNANT GUIDEIt has car toon foxes. Foxen? It has cartoon foxen.


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MR. NEIGHBORLYSHUMBLE LITTLE

RUBY BOOKPragmatically chunky bacon


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Not so free stuff(but still really good)


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RUBY IN A

NUTSHELLCome on. Matz wrote it.


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RUBY IN

PRACTICELook at that funny looking guyon the cover. At least its not anasty monkey. Sorry, OReilly


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THE RUBY

WAY


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RUBY FOR

RAILS


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THE WELL-GROUNDED

RUBYIST


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RAILS HAS OPINIONSAnd Ruby Likes To Talk


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Rails is opinionated software


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Ruby is a communicative language


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Sometimes, Ruby just wantssomeone to listen to it.


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If youre programming along, doing nicely, andall of a sudden your program gets balky, makes

things hard for you, its talking. Its telling youthere is something important missing.

Kent Beck, Smalltalk Best Practice Patterns


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It is your responsibility to

listen to your code and beconsiderate of its needs.


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Write Ruby code that

communicates well but berespectful of Rails opinions


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Other people who use your code

(including six-months-later you)will thank you.


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Ruby makes it easy to writesimply, clearly and expressively


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Rails has powerful idiomsand conventions


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Combining the two makes for ahappy, fulfilling relationship


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RUBY LOVES YOUBut Sometimes You Drive Her Crazy


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These are some of the things youdo that drive Ruby crazy.


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Youre welcome.


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# Bad

i = 0; while i < array.size do

puts array[i]i += 1

end

# Better

for item in array

puts item

end

# Bestarray.each do |item|

puts item

end


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WHY?

Ruby has powerful iterators.

You dont need to write your own.

for ... in ... just calls #each internally.


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# Bad

value = value ? value : "default"

# Bettervalue = value || "default"

# Best

value ||= "default"


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WHY?

Ternaries (the ? : thing) are ugly.

Ruby has pretty assignment with operators like += and ||=


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# Bad

array


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WHY?

Sometimes it just helps to know what set union is.


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# Bad

if value != nil && value != false

# Good

if value


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WHY?

Ruby has a sane notion of truthiness


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# Bad

if value == 1 || value == 12 || value == 42

# Good

if [1,12,42].include? value


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WHY?

Brevity is not the goal

Readability is the goal

But if it is more readable and also shorter, go for it.

# Bad


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# Bad

def request

begin

perform_requestrescue RequestError => e

log_error e

end

end

# Good

def request

perform_request

rescue RequestError => e

log_error e

end


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WHY?

Method definitions are an implied begin block.


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# Bad!!value

# Good

value


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WHY?

Ruby does not not like clarity.

What you lose in readability you gain in nothing.


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# Bad

ActiveRecord::Base

# Good

ActiveRecord::Model


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WHY?

Naming things is important.

Base? What does that even mean?

Sorry Rails, you got this one wrong. Better luck next time.


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# Bad

class PostsController < ApplicationController

def recent

Post.find :all, :conditions => ['posts.created_at > ?',

1.week.ago]

end

end


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# Good

class PostsController < ApplicationController

def recentPost.within 1.week

end

end


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class Post < ActiveRecord::Base

named_scope :within,

lambda {|seconds| :conditions => ['posts.created_at > ?',seconds.ago]}

end


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WHY?

Make your code more expressive

And more intention revealing.

In other words, say what you mean to say.


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url_for(:blog, :posts, @post.id, :comments, :replies => true)# => http://example.com/blog/posts/19/comments?replies=true
http://example.com/blog/posts/19/comments?replies=truehttp://example.com/blog/posts/19/comments?replies=true


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# Bad

def url_for(*args)

root + args.map{|arg| parse_arg(arg)}.join('/').gsub('/?', '?')

end

def parse_arg(arg)

case arg

when Array: arg.join('/')

when Hash

ret = []

each{|k,v| ret


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# Good

def url_for(*args)root + args.to_params

end


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# Array

%w(foo bar bazz).to_params # "/foo/bar/bazz"

# Hash

{:foo => :bar}.to_params # "?foo=bar"


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WHY?

Ruby uses coercion in many places

1.to_s

(1..10).to_a

Writing your own coercion method can help you use Rubysducktyping.

Separation of concerns.


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RAILS PERFORMANCEInsert your scaling and premature optimization jokes here.


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Yes, I went there.


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Slow is only meaningfulin comparison.


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Ruby is slow? Compared to what?


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Is your database slow?


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Are your views slow?


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Is your app server slow?


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Are you using HTTPvia carrier pigeon?


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If you dont know where the slowis, youre not ready to optimize.


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Dont optimize prematurely, butdont pessimize either.


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Dont write code you know willnever, ever be fast.


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# Really Bad (Optimally Pessimum)

class Ballot < ActiveRecord::Base

def (other)

votes.count other.votes.count

end

end

# Good (Potentially Optimum)

class Ballot < ActiveRecord::Base

# With a counter_cache on votesdefault_scope :order => :votes_count

end


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IN CONCLUSION

Ruby is fun and easy (and friendly!).

Ruby will make you happy.

Be more thoughtful in the way you treat Ruby.

The more Ruby you know, the better you can become at Rails.

If you love Rails, you should love Ruby too.

Also, dont be premature. No one likes that.


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WHO AM I?

My name is Rein Henrichs.

Thats pronounced like rain.

But spelled differently.

I work at

I blog at reinh.com

I twitter @reinh

I lik dl lit di d l lk th b h
https://twitter.com/home?status=@ReinHhttp://reinh.com/https://twitter.com/home?status=@ReinHhttp://reinh.com/http://reinh.com/https://twitter.com/home?status=@ReinH

Rails Is from Mars, Ruby Is from Venus

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