Alternate between showing two images in a Rails view

Firstly I apologize for this as I am not a Rails programmer.. I just need to figure this out so that I can get back to productive work.

I have inherited a RoR site and need to have an image that rotates randomly on page load. Simple, right?

My solution was to generate a random number between 0 and 2. If the number is above 1 show one image, else show the other. I had put this into a sidebar.erb file :

<div class="shadow">

<%- if rand(2) > 1 %>
        <img src="foo.png"/>
<%- else %>
        <img src="bar.png"/>
<%- end %>
                </div>

I 开发者_运维百科get the following error in the site logs:

warning: else without rescue is useless

I'm probably doing this completely wrong. Honestly, I just need this to work with minimal effort. Any help would be greatly appreciated.

---

First, you would need to calculate the random number in your controller and put it in an instance variable like :

@image_random = rand(2)

Then, in your view :

<% if @image_random == 1 %>
        <%= image_tag "foo.png" %>
<% else %>
        <%= image_tag "bar.png" %>
<% end %>

You can safely lose - after <% in Rails 3 :) It's been done automatically.

Bear in mind that rand(2) will either give back 0 or 1. So checking for random > 1 will always come out as false.