将这样的逻辑移到控制器或模型而不是视图？

Question

I have this logic currently in my view

<% tools_count = @job.tools.count - 1 %>
    <% count = 0 %>
    <% @job.tools.each do |u|%>
        <%= u.name %>
        <% if count != tools_count  %>
        <% count += 1 %>
        <%= "," %>
    <%end%>
<% end %>

Which just loops through some users relations and puts in a , unless it is the end of the list.

My question: This kind of logic looks really messy and clogs up my views I know there must be a better way of doing this by moving it into the controller or maybe model, does anyone know the correct way to do this kind of logic?

Answer 1

You can add a method like this to your Job model:

def tool_names
  tools.map(&:name).join(',')
end

And use it in your view like this:

<%= @job.tool_names %>

Answer 2

There are couple of ways to avoid putting this kind of logic in the view layer:

1. Create an instance method in the model class (as spickermann suggested)

This will work for simple logic and simple projects. However, when you will want to use some helpers from ActionView::Helpers such as jobs_path or number_to_currency , a model is not a good place for it.

2. Create a helper method in helper modules eq. JobHelpers

Generally you can put any helper methods related to view layer in helpers. For example to share common methods for building a view components.

3. Use the decorator/presenter pattern and put there the view logic so model won't be polluted. Here is some more explanation about the pattern and sample implementation using draper gem: http://johnotander.com/rails/2014/03/07/decorators-on-rails/

Answer 3

您可以像这样一行

<%= @job.tools.map(&:name).join(',') %>