collection_select, undefined method `map' for nil:NilClass

ruby-on-rails

Solution

`@user_array` is `nil`. Make sure it's set with an array of users to avoid this error message.

Alternatively, set `@user_array` to `[]` (an empty array) if you wish to show no options in the `select, e.g.:

collection_select @user, :full_name, @user_array || [], :id, 
  { prompt: 'true' }, { class: 'select' }

Problem

I added in the `@user = User.new` line to make sure it isn't nil. Which object is nil? ``` undefined method `map' for nil:NilClass Extracted source (around line #11): 8: <%= f.hidden_field(:width)%> 9: <%= f.hidden_field(:height)%> 10: <% @user = User.new %> 11: <%= collection_select(@user, :full_name, @user_array, :id, {:prompt => 'true'}, {:class=>'select'})%> 12: <div class="submit-button"> 13: <%= submit_tag("Tag the person!")%> 14: </div> ```

Original source