Refactoring Ruby

Question

I have three arrays, two of which come from JSON.

I need to check if each array is not nil and the count is greater than 0. If any are greater than 0 display "Hello World" else display "Boo".

<% if !@arrayOne.nil? && @arrayOne.count > 0 || !@user_json[:user_stuff].nil? && @user_json[:user_stuff].count > 0 || !@user_json[:more_user_stuff].nil? && @user_json[:more_user_stuff].count > 0 %>
<h1>Hello World</h1>
  <% else %>
<h1>Boo</h1>
<% end %>

I need some help refactoring this code and would like to learn other ways to approach this.

score 5 · Accepted Answer · edited Dec 16 '15 at 16:25

5

You can use array.blank? (assuming you're using Rails of course) to check whether an array is nil or empty, such as:

<% if !@arrayOne.blank? || !@user_json[:user_stuff].blank? || !@user_json[:more_user_stuff].blank? %>

Rule of thumb you should move as much logic to the controller as you can.

As suggested in the comments, you can also use present?, which is the same as !blank?, improving readability a bit:

<% if @arrayOne.present? || @user_json[:user_stuff].present? || @user_json[:more_user_stuff].present? %>

edited Dec 16 '15 at 16:25

the Tin Man

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answered Dec 16 '15 at 15:29

Leo Brito

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If the `@arrayOne` is `nil`, this will throw `NoMethodError: undefined method 'blank?' for nil:NilClass`. (Same for `@user_json[:user_stuff]`, `@user_json[:more_user_stuff]`) – falsetru Dec 16 '15 at 15:33
@falsetru do you mean if @arrayOne etc are `undefined`? AFAIK `blank?` tests for nil before testing empty, such that `nil.blank?` returns true. – Leo Brito Dec 16 '15 at 15:38
1

@falsetru [blank?](http://apidock.com/rails/Object/blank%3F) is a Rails API function, not a Ruby core function. Calling blank? in irb will in fact result in the undefined error. – Leo Brito Dec 16 '15 at 15:44
3

`!foo.blank?` could be written as `foo.present?`. What reads much nice IMHO. – spickermann Dec 16 '15 at 16:00
It's not necessary to use Rails to take advantage of `blank?` or `present?`. See http://stackoverflow.com/questions/4238867/how-do-i-use-active-support-core-extensions/4239625#4239625. – the Tin Man Dec 16 '15 at 16:24

score 3 · Answer 2 · answered Dec 16 '15 at 15:32

3

You can use Enumerable#all?:

<% if [!@arrayOne, @user_json[:user_stuff], @user_json[:more_user_stuff]].all? { |x|
  x && x.count > 0
} %>
  ...

answered Dec 16 '15 at 15:32

falsetru

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score 1 · Answer 3 · answered Dec 16 '15 at 15:57

I would start with something like this:

if [@arrayOne, @user_json[:user_stuff], @user_json[:more_user_stuff]].any?(&:present?)

In a next step I would move that condition into a helper with a nice name. Unfortunately you did not provide why you need this check (that why would hint a good name). But as an idea:

# in a helper
def something_to_show?
  [ @arrayOne, @user_json[:user_stuff], @user_json[:more_user_stuff]
  ].any?(&:present?)
end

# in the view
<% if something_to_show? %>
  <h1>Hello World</h1>
<% else %>
  <h1>Boo</h1>
<% end %>

score 0 · Answer 4 · edited Jan 28 '20 at 18:26

0

A simple way that doesn't require Rails:

puts [a, b, c].map(&:to_a).all?(&:empty?) ? 'Boo' : 'Hello World'

edited Jan 28 '20 at 18:26

the Tin Man

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answered Dec 16 '15 at 23:52

pguardiario

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Refactoring Ruby

4 Answers4