Stop rails console from printing out the object at the end of a loop

Question

If I, say, loop through all the instances of a given model and output something from each, at the end, irb will still print the entire object.

If the object ends up taking hundreds of lines, it'll be a long way up before I see what I was actually looking for. Is there a way to disable this in the rails console?

Spine

Answer 1

If you don't want to disable the echo in general you could also call multiple expressions in one command line. Only the last expression's output will be displayed.

big_result(input); 0

Bromeosin

this is actually what I wanted. – Spine

I often do big_result(input); nil – Betteann

Answer 2

Call conf.echo = false and it will not print the return value. This works for any irb session, not just Rails console.

In case you want to make it permanent, add it to your irb config.

echo 'IRB.conf[:ECHO] = false' >> $HOME/.irbrc

Reasonable

What would you do if you wanted to have this always be the case by default? – Triquetrous

@Accipheran I guess putting it in the Rails initializers would work. – Reasonable

Thanks for the response, I actually found that just throwing the line IRB.conf[:ECHO] = false, in my .irbrc file took care of it. That of course also turns of the echo in all my irb sessions, but I'm okay with that. – Triquetrous

Is there a way to set it temporarily (in just the current console session)? – Phonometer

Running conf.echo = false from the rails console gives NameError: undefined local variable or method 'conf' for main:Object from (pry):6:in '<main>' – Phonometer

@Phonometer I wonder if it is because you are using pry. – Reasonable

@Reasonable I just checked against an app that has pry-rails gem and one that doesn't, and running conf.echo = false in the rails console worked in the app that doesn't have it and didn't work in the that has pry-rails. I wonder if there's an equivalent for apps using pry? – Phonometer

Answer 3

Update for Ruby 3.3: As a part of the improvements to irb, we can now omit the return value with ;

Reference: https://blog.saeloun.com/2024/02/12/what-is-new-in-ruby-3-3/

To temporarily stop the console from printing the return values you can issue a nil statement at the end of your loop or function, but before pressing the return.

record.each do |r|
  puts r.properties
end; nil

Or it can be a number too, if you want to reduce typing. But it can be confusing in scenarios, which I can't think of.

record.each do |r|
  puts r.properties
end; 0

Villose

you are the best! – Thracophrygian

Answer 4

This frustrated me a lot, because I was using pry-rails gem, some solutions wouldn't work for me.

So here's what worked in 2 steps:

1. Simply adding ; to the end of the very last command will be enough to silence the output from printing.
2. It may still print the sql that was executed. So to silence that, surround it with

ActiveRecord::Base.logger.silence do
  # code here
end

Example

If you want to run this

User.all do |user|
  puts user.first_name
end

then this will ensure nothing else prints to screen:

ActiveRecord::Base.logger.silence do
  User.all do |user|
    puts user.first_name
  end
end;

(don't forget the ; at the very end)

Phonometer