如何获得红宝石中对象的属性？

Question

I'm new to Ruby and Rails. I've been trying to get a view of all users to work and am not sure what I'm doing wrong.

I have a view with:

<% provide(:title, "View all Users") %>

<h1>Users#viewall</h1>
<p>Find me in app/views/users/viewall.html.erb</p>

<% 
@users = User.all 
@users.each do |user|
  user.name
end
%>

The output of this is a list of objects in the database, with all the object's data. When I want to target (for example) just the name, it doesn't work.

[#<User id: 1, name: "user name", email: "mail@mail.com", created_at: "2016-08-03 15:40:41", updated_at: "2016-08-03 15:40:41", password_digest: "$2a$10$KmWWK86H/dj.HAp9zcHOUOCbph1rawIer41kyH4dIrV...">]

What am I missing here? I'm not even really sure what to google as I don't know what the loop is spitting out.

Answer 1

You are not displaying the data to the user.

In your controller method, is where you should add

@users = User.all 

And in your view

<% @users.each do |user| %>
  <h1><%= user.name %></h1>
<% end %>

• <% %> : These brackets are used to evaluate an expression
• <%= %> : These brackets evaluate an expression and render the output

Answer 2

You need to output the information. So in ERB when you have a tag like:

<% i = 4 %>

That executes code. When you have:

<%= "hi" %>

That outputs the return value. So what you actually want is this:

<% User.all.each do |user| %>
  <%= user.name %>
<% end %>

What you should do with the users though, is setup an instance variable in your controller:

def viewall
  @users = User.all
end

Then use it in your view:

<% @users.each do |user| %>
  <%= user.name %>
<% end %>

Just better to keep SQL calls and a lot of logic out of your views. Leverage the controllers, models and helpers to do that.