CODEWITHSUNDEEP
ruby-on-railsruby
superbot
superbot

Reputation: 461

Showing the email of the person to whom I sent a comment

I use the following code to show the email of the person to whom I sent a comment.

Controller:

@to_user = User.where(id: @comment.to_id)

View:

<%= @to_user.email  %>

Only it generates an error: undefined method `email' for #<User::ActiveRecord_Relation:0x007feb364b8218>

Showing "from" user works well: 

<%= @comment.user.email %>

Not sure what I am doing wrong. Help would be much appreciated.

Upvotes: 0

Views: 28

Answers (2)

Stefan
Stefan

Reputation: 114178

To retrieve a single object, you use find:

@to_user = User.find(@comment.to_id)

But it's more idiomatic to define a belongs_to association in your Comment model, e.g.:

class Comment < ActiveRecord::Base
  belongs_to :to_user, class_name: 'User', foreign_key: 'to_id'
  # ...
end

This allows you to simply write:

<%= @comment.to_user.email %>

To avoid confusion, you might want to rename the exising user to from_user. Or maybe use more descriptive names like sender and receiver.

And if you do so, it would be a good idea to also rename the columns from user_id and to_id to from_user_id and to_user_id (or sender_id and receiver_id).

Upvotes: 2

max pleaner
max pleaner

Reputation: 26768

.where returns an ActiveRecord_Relation, which you can think of like an array of records (actually, the records aren't loaded yet, but as soon as you call a method like .each or .to_a it evaluates the query and turns it into an array).

What you are looking for is either

  • .find (User.find(@comment.to_id)) - this will raise an error if the user is not found
  • .find_by (User.find_by(id: @comment.to_id)) - this will return nil if the user is not found

You could also just call .first on the .where result - as often is the case in Ruby/Rails, there are many ways to do the same thing.

Upvotes: 1

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