Ruby, better way to implement conditional iteration than this?

I have an array @cities = ["Vienna", "Barcelona", "Paris"];

and I am trying to display the individual items with a spacer in between. However it is possible that there is only 1 element in the array, in which case I do not want to display the spacer. And also the array could be empty, in which case I want to display nothing.

For the above array I want the following output:

Vienna
-----
Barcelona
-----
Paris

I use an erb template cityview to apply formatting, css, etc before actually pri开发者_运维问答nting the city names. Simplified, it looks like this:

<p><%= @cities[@city_id] %></p>

I have implemented it as follows...

unless @array.empty?
    @city_id = 0;

    erb :cityview
end

unless @array[1..-1].nil? 
    @array[1..-1].each_index do |i|
        @city_id = i+1;

        puts "<p>-------</p>";

        erb :cityview
    end 
end

Is there a better way?

---

@cities.join("<p>--------</p>")

Edit to address the template

Here I'm assuming that there's an erbs method that returns the rendered template without doing a puts. Returning the string allows easier manipulation and reuse.

@cities.map { |c| @city = c; erb :cityview }.join("<p>--------</p>")

---

I'd prefer:

erb:

<p><%= @city %></p>

and loop

@array.each_with_index do |e, i|
    @city = e
    erb :cityview
    puts "<p>-------</p>" if i < @array.length - 1
end

I assume you have split the erb, bit because you want to customize it.

---

If you want to mix HTML with your city names then you'll need to worry about HTML encoding things before you mix in your HTML. Using just the standard library:

require 'cgi'
html = @cities.map { |c| CGI.escapeHTML(c) }.join('<p>-----</p>')

If you're in Rails, then you can use html_escape from ERB::Util and mark the result as safe-for-HTML with html_safe to avoid having to worry about the encoding in your view:

include ERB::Util
html = @cities.map { |c| html_escape(c) }.join('<p>-----</p>').html_safe

---

The simpler solution would be to use a spacer template.

http://guides.rubyonrails.org/layouts_and_rendering.html#spacer-templates