Question

I need to check, if for each item in @line_items if it is in different array say @quote_items

Controller:

def index
  @line_items = LineItem.all
  @quote_items = QuoteItem.all
end

View:

<% for line_item in @line_items %>
   <% if @quote_items.include?(line_item) %>
     line_item in quote item! 
   <% else %>
     line_item NOT in quote item! 
   <% end %>
...
<% end %>

Is there an easy way to do this? include? doesn’t seem to work the way I want. Seems to just yield false for me all the the time.

Answer 1

You are right it will always return false because you are trying to check if the array of @quote_items has a line item object

@quote_items.include?(line_item)

which obviously will always be false because your @quote_items instance is an array of QuoteItem objects and @line_items instance is an array of LineItem object. So they are always different objects.

I think in this situation you may want to compare some common attribute of quote_item and line_item. For example if you want to compare name attribute then

quote_item_names = @quote_items.map(&:name)

and then

<% if quote_item_names.include?(line_item.name) %>
 line_item in quote item! 
<% else %>
 line_item NOT in quote item! 
<% end %>