dom_id

The DOM id convention is to use the singular form of an object or class with the id following an underscore. If no id is found, prefix with “new_” instead.

dom_id(Post.find(45))       # => "post_45"
dom_id(Post.new)            # => "new_post"

If you need to address multiple instances of the same class in the same view, you can prefix the dom_id:

dom_id(Post.find(45), :edit) # => "edit_post_45"
dom_id(Post.new, :custom)    # => "custom_post"