Switch case statement in coffee script

There are two forms of switch in CoffeeScript:

switch expr
    when expr1 then ...
    when expr2 then ...
    ...
    else ...

and:

switch
    when expr1 then ...
    when expr2 then ...
    ...
    else ...

The second form might help you:

view = switch
  when target.hasClass 'red' then new App.RedView
  when target.hasClass 'blue' then new App.BlueView
  when target.is '#black' then new App.BlackView
  else null

You could leave out the else null if undefined is an acceptable value for view. You could also wrap the logic in an (explicit) function:

viewFor = (target) ->
    # There are lots of ways to do this...
    return new App.RedView   if(target.hasClass 'red')
    return new App.BlueView  if(target.hasClass 'blue')
    return new App.BlackView if(target.is '#black')
    null

view = viewFor target

Giving your logic a name (i.e. wrapping it in a function) is often useful for clarifying your code.