Calculate and display user age in the view

Question

I have a date_field :born_in for age and i want to display the calculated user age in user profile instead of the regular date format mm/dd/yyyy

I found a method in this answer on how to calculate user's age but i don't know how to implement it in my rails app.

user_information.rb

class UserInformation < ApplicationRecord
  belongs_to :user

  has_one :gender, :dependent => :destroy
  accepts_nested_attributes_for :gender, :allow_destroy => true

  has_one :relationship, :dependent => :destroy
  accepts_nested_attributes_for :relationship, :allow_destroy => true
end

show.html.erb

<%= @user.user_information.try(:born_in) %>

What have you tried? What does your User model look like? – moveson Sep 02 '19 at 01:09 — moveson, Sep 02 '19 at 01:09
@moveson i have included my model to my question – seddka Sep 02 '19 at 09:45 — seddka, Sep 02 '19 at 09:45

score 1 · Answer 1 · answered Sep 02 '19 at 01:46

1

Put the method in your model as a property (instance function rather than class function ) then in your form just pop the result into the page. You have shown no code whatsoever so I can not give you a code example to fix your problem but something like this maybe

class Person ...
  ...

  def calculated_age
    now = Time.now.utc.to_date
    now.year - dob.year - ((now.month > dob.month || (now.month == dob.month && now.day >= dob.day)) ? 0 : 1)
  end

Then in your view

<%= @person.calculated_age #Or whatever your instance variable name is %>

You might also want to add a check that dob is not null and set an appropriate default in the model

This is exactly what models are for. Views should just render the information they are given Show more code next time and help people to help you.

answered Sep 02 '19 at 01:46

jamesc

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I have updated my question and included my nested model to devise users model. i got this error `undefined local variable or method `dob' for #` – seddka Sep 02 '19 at 09:42
@seddka You have supplied no code at all related to your new error. I can't help with no information – jamesc Sep 02 '19 at 19:44
@seddka where did you define dob? – jamesc Sep 03 '19 at 01:43
i got it working, i'll post an answer about it . thank you for your help, appreciate it ! – seddka Sep 03 '19 at 14:46

score 0 · Answer 2 · answered Sep 03 '19 at 14:54

before i tried @jamesc solution:

def calculated_age
    now = Time.now.utc.to_date
    now.year - dob.year - ((now.month > dob.month || (now.month == dob.month && now.day >= dob.day)) ? 0 : 1)
  end

but i got an error saying :

undefined local variable or method dob' for #<UserInformation:0x00007feccd3a0d60>

That's because dob was not defined in the calculated method .

This is the solution i came up with :

def age
    now = Time.current
    dob = self.born_in
    now.year - dob.year - ((now.month > dob.month || (now.month == dob.month && now.day >= dob.day)) ? 0 : 1)
  end

And in Users profile show.html.erb all i had to do is :

<%= @user.user_information.age %>

Calculate and display user age in the view

2 Answers2