An easy way to add a link to a form that changes the submit action from the default format to .pdf, .csv, etc. and then submits the form.

jquery-dynamic-submitable.coffee

# Function allows you to change the action of a form when clicking a link. This comes
# in handy when you want to change the format of a form from its default to .csv, .pdf
# or something other than the default. This is also set up to work outside of the
# <form></form> tag.
#
# Typical use:
#
#    <%= link_to '#', data: { behavior: "dynamicsubmitable", target: "#form_id", link: resource_path(format: :pdf) } %>
#
$ = jQuery
$.fn.extend
  dynamicSubmitable: ->
    $(@).each (i, el) ->
      new DynamicSubmitable($(el))

class DynamicSubmitable
  constructor: ($a) ->
    @init($a)

  init: ($a) ->
    $a.on "click", ->
      link = $a.data('link')
      targetFormId = $a.data('target')
      old_action = $(targetFormId).attr('action')
      
      $(targetFormId).attr('action', link)
      $(targetFormId).submit()
      $(targetFormId).attr('action', old_action)

jQuery ->
  $("[data-behavior~='dynamicsubmitable']").dynamicSubmitable()

DISCLAIMER: I am not a Javascript/Coffescript programmer, so if anyone has a better way to do this please share.