Ruby don't do actions for nil class in if block

Question

How to achieve sth like if params[:filters][:company_name] is present (not nil) then do below actions but if it's nil - skip and do the rest of the code below/outside of this if ?

if params[:filters][:company_name]
  contains = Process
             .where(
               'company_name LIKE ?', "#{params[:filters][:company_name].downcase}%"
             )
end

Well, you can do it exactly as shown in your code. Do you experience any problem with it? — Holger Just, Oct 23 '19 at 15:42
@HolgerJust This code will throw an error if `params[:filters]` is `nil` — Viktor, Oct 23 '19 at 15:44

Tom Lord · Accepted Answer · 2019-10-23T20:28:17.457

I'm assuming your problem is that the code "blows up" if params[:filters] is nil. (You get an error: "undefined method :[] for nil:NilClass".)

There are multiple ways to handle this, but probably the most concise is to use Hash#dig:

if params.dig(:filters, :company_name)
  # ...
end

This won't fail if params[:filters] == nil. From the above linked documentation (emphasis is mine):

Extracts the nested value specified by the sequence of key objects by calling dig at each step, returning nil if any intermediate step is nil.

score 0 · Answer 2 · answered Oct 23 '19 at 15:43

0

Try changing

if params[:filters][:company_name]

to

if params[:filters] && params[:filters][:company_name]

answered Oct 23 '19 at 15:43

Mark

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Ruby don't do actions for nil class in if block

2 Answers2