Below is my very own, very first, super-clean, super-sexy CoffeeScript snippet that dynamically appends input fields as the user tabs through the current input field. The source-code is on the left. On the right you can actually play with it and see it in action!
inputId =1;
jQuery ->
$("#fields :input").live'keydown',(e)->if isModifierKeyPressed e
returnif e.keyCodein[9,13]
e.preventDefaultif isLastActivity($(this).attr'id')
addAnotherTextInput();
$(this).next().focus();returnfalse
isModifierKeyPressed =(e)->
e.ctrlKey or e.altKey or e.shiftKey
isLastActivity =(inputFieldId)->
inputNumber =(Number) inputFieldId.split('activity')[1]
inputNumber == inputId
addAnotherTextInput =->
inputId++
$("#fields").append getInputField inputId
getInputField =(inputId)->return"<input type='text' id='activity#{inputId}'
class='input-super-large'
placeholder='Type something and then press tab' />"
