CODEWITHSUNDEEP
rubyrubygems
alanp
alanp

Reputation: 149

What's the best way to do multiple requires in Ruby?

I'm not sure I've seen this addressed, but I am wondering what is the best way to do multiple requires in a ruby script. I have come up with a couple rudimentary examples which I will outline below, but I'm not sure if there is a best practice for this -- my search results have come back with nothing.

0) Bunch of includes & exceptions (I'll leave the rescue out)

require 'rubygems'
require 'builder'

1) String array

torequire = ['rubygems', 'builder']
begin
  torequire.each do |req|
    require req
rescue LoadError => e
  # Not sure if this is great either
  puts "Missing required gem: " + e.message.split[-1]
  exit
end

2) ??

Is there a large problem created from loading them all from a string array? You could specify version requirements or locations similarly, I'm just wondering if there is a problem with doing it this way.

Upvotes: 11

Views: 5685

Answers (5)

gsb
gsb

Reputation: 107

This isn't the best, but if you do:

def require_all(*gems)
   g = *gems
   g.each {|gem| require gem }
end

Alternatively add this one-liner to the beginning of your code:

def require_all(*gems); g = *gems; g.each { |gem| require gem }; end

You can just pass multiple gems to require_all; e.g.

require_all 'rack', 'bundler', 'rails'

And so on. Got the idea from the above answer!

Upvotes: 0

mahemoff
mahemoff

Reputation: 46489

%w(rubygems rack rails).each { |gem| require gem }

or, with a reusable function:

def require_all(gems) ; gems.each { |gem| require gem } ; end
...
require_all %w(rubygems rack rails)

Neither is popular Ruby style (especially a one-liner function), but Ruby embraces TIMTOWTDI, so use them if they work for you.

Upvotes: 0

Wayne Conrad
Wayne Conrad

Reputation: 108139

The plain way is the best way.

You could do this, but it trades clarity for cleverness--a poor bargain:

[
  'rubygems',
  'rack',
  'rails'
].each(&method(:require))

Skip the "rescue" with the fancy error message. Everyone knows what it means when a require throws a stack trace.

If you want to make it easier for someone using your program to have the required gems installed, check out bundler.

Upvotes: 17

JUST MY correct OPINION
JUST MY correct OPINION

Reputation: 36107

In the first one it is clear what you're doing.

In the second it requires someone to decode what you're doing.

It seems a bit whimsical to force everybody to decode what you're doing so you can save a few lines of typing (and that only if you're using a whole lot of libraries in one source file which is a bit of code smell in and of itself). Remember that code is read an order of magnitude or three times as often as it is written. If it's a choice between easy writing or easy reading, the reading should win out.

Upvotes: 5

Sam 山
Sam 山

Reputation: 42863

All of the ruby scripts i have seen just list one require per line like you have first.

require 'rubygems'
require 'rack'
require 'rails'

Upvotes: 17

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