nil can't be converted to a Time value - html

Question

Im building a basic chat room website with multiple chat rooms that users can comment on.
I managed to get my messages/comments to show up on each Room.show page, however when I go to enter
<p><%= message.user.name if message.user %> <small><em><%= "#{time_ago_in_words(message.created_at)} ago" %></em></small></p>
I receive a nil can't be converted to a Time value error. Also, I cannot get the Users name to show up. It just registers blank.
Here is the section of my Room.show.html.erb that is registering an error
<% #message.each do |message| %>
<div class="row">
<p><%= message.user.name if message.user %> <small><em><%= "#{time_ago_in_words(message.created_at)} ago" %></em></small></p>
<p><%= message.body %></p>
</div>
<% end %>
Here is my Message controller
def show
#rooms = Room.all
#message = #room.message
end
Here is my Routes file
Rails.application.routes.draw do
devise_for :users
#resources :messages
resources :users
resources :rooms do
resources :messages
end
root 'rooms#index'
end
Message.rb
class Message < ApplicationRecord
belongs_to :user
belongs_to :room
end
And room.rb
class Room < ApplicationRecord
has_many :message
end
Using updated version of rails.

Answer 1

message.created_at is nil. You can verify it by changing your code slightly:
<%= "#{time_ago_in_words(message.created_at || Time.now)} ago" %>
This will always show less than a minute ago because message.created_at is nil.
<%= "#{time_ago_in_words(message.created_at)} ago" if message.created_at %>
This will not show anything because message.created_at is nil.
I suggest that you use a debugging library like pry to help you troubleshoot this. You could do something like this:
<% #message.each do |message| %>
<div class="row">
<% binding.pry unless message && message.created_at %>
<p><%= message.user.name if message.user %> <small><em><%= "#{time_ago_in_words(message.created_at)} ago" %></em></small></p>
<p><%= message.body %></p>
</div>
<% end %>
That will set a breakpoint that will be triggered if message or message.created_at are nil, and allow you to use the Rails console to inspect the variables to help narrow down the problem.
Like others mentioned, you will need to make sure your models are appropriately constructed:
class Room < ApplicationRecord
has_many :messages
end
You should also check your schema.rb to ensure that the Message model has the following:
t.datetime "created_at", null: false
t.index ["room_id"], name: "index_messages_on_room_id"
The first is needed because without it message.created_at will not exist at all, and the second is needed for the association between the two models.
Your controller code doesn't make any sense and I'm assuming that you manually typed it into your question rather than copying and pasting it. You define #rooms as an ActiveRecord::Relation collection object, but you call #room.message. If you meant #rooms.message then that won't work because you're trying to call an instance method on a collection. I'm not sure what you meant here because the code doesn't make sense.
Additionally, you're not implementing a clean CRUD solution. Your Messages controller's show method should be for rendering a single Message object, not for rendering a collection of rooms' messages.
In general there are many problems with the code, the structure, and the example you have typed out. At the very least though, you must make sure that message.created_at is not nil before attempting to call time_ago_in_words, and that all traces back to:
making sure your models are correctly formed and associated with each other
making sure your controller is fetching real objects
making sure your view is appropriately iterating over those real objects