dynamically change method name inside array in ruby

Question

I have a user object which i access like this.. user.email, user.first_name

Now I want to loop through each and return a message based on the current key in loop somewhat like this.

[user.first_name, user.email, user.last_name].each do |key|
      puts "#{key} is required"
 end

The above works but loops through values instead of fields. so will do this below but how to prepend user to keys and get values inside array?

[first_name, email, last_name].each do |key|
 #inside here I want to prepend the user to the keys so that I can access like user.key 

 puts "#{user.key} is required" 
end

If this was a string we can concatenate but how to deal with this here as its a method call?

Are you asking how to use `key` as a method call on `user`? – jvillian Mar 29 '17 at 19:29 — jvillian, Mar 29 '17 at 19:29

score 2 · Accepted Answer · answered Mar 29 '17 at 19:53

With ActiveRecord you can access properties via the [] method:

[ :first_name, :email, :last_name ].each do |key|
  unless (user[key])
    puts "#{key} is required"
  end
end

This generally a lot safer than the send approach because it's not calling arbitrary methods.

score 1 · Answer 2 · answered Mar 29 '17 at 19:30

1

You can simply do:

user.send(key)

answered Mar 29 '17 at 19:30

jvillian

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score -1 · Answer 3 · answered Mar 29 '17 at 19:30

-1

[first_name, email, last_name].each do |key|
 puts user.send(key)
end

answered Mar 29 '17 at 19:30

Ruslan

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dynamically change method name inside array in ruby

3 Answers3