Hampei

# normally paperclip uses the server/bucket/location format, but that breaks when you have a eu bucket. 
# This one works for all buckets.
# put in an initializer (or somewhere else) and add this to has_attached_file params
#  :url => ':s3_url',

Paperclip.interpolates(:s3_url) { |attachment, style|
  "#{attachment.s3_protocol}://#{attachment.bucket_name}.s3.amazonaws.com/#{attachment.path(style).gsub(%r{^/}, "")}"
}

Hampei

# in application.rb add
# config.middleware.insert 0, "RedirectFromWww" # first, so you don't need a certificate for the www. version
class RedirectFromWww
  def initialize(app)
    @app = app
  end

  def call(env)
    request = Rack::Request.new(env)
    if request.host.starts_with?("www.")

Hampei

# response-html of forms replace the innerHTML of given element.
# usage <form data-remote='true' data-replace-element='#replace_my_contents'>...
$(document).on("ajax:success", "form[data-replace-element]", (el, data, status, xhr) ->
  $($(this).data('replace-element')).html(data);
);

Hampei

# Use for serialized Array attributes, to add a link to add rows for it in the form.
# Last child is saved and appended on click.
# .field.repeat_last{data: {'link-name' => 'add item'}}
#   .item
#     = f.text_field :name
#     = f.text_field :url
$(->
  $('form .repeat_last').map(->
    el = $(this)
    last_child = el.find('>*:last-child').clone()

Hampei

module ActionView
  module Helpers
    class FormBuilder
      # - f.fields_for_array_of_hashes :links do |lnk|
      #   .item
      #     = lnk.text_field :name
      #     = lnk.text_field :url
      def fields_for_array_of_hashes(record_name, record_object = nil, options = {}, &block)
        @object.send(record_name).each do |e|
          e = OpenStruct.new(e)

Hampei

function copy_jquery_on_event_handlers(source, target) {

  $.each(['click', 'submit', 'ajax:beforeSend', 'ajax:complete'], function(i, event_type) {
  
    $.each($._data(source, 'events')['click'], function(j, jqe_spec) {
    
      if (jqe_spec.selector != undefined)
        $(target).on(event_type, jqe_spec.selector, jqe_spec.handler);

    });

Hampei

// browser support: chrome, safari, firefox, opera, ie9+, ieMobile10+ (Opera Mini not supported)
// No external libraries needed.

// calls fn on all current and future elements matching selector within the first element matching container_selector.
// find_with_mutations('.container', '.element', function(el) {  })
window.find_with_mutations = function(container_selector, selector, fn) {
  var observer = new MutationObserver(function(mutations) {
    mutations.forEach(function(mutation) {
      [].slice.call(mutation.addedNodes).forEach(function(el) {
        if (el.nodeType !== 1) return;

Hampei

// Turns all textareas into medium-editors
// requires: 
//  - Medium-Editor
//  - jQuery (can be easily rewritten without)
//  - find_with_mutations: https://gist.github.com/hampei/7620643
//  - sync_node_html_to_form_field: https://gist.github.com/hampei/7620825
window.textareas_to_medium_editor = function() {
  find_with_mutations('form', 'textarea', function(el) {
    el.style.display = 'none'; // hide the textarea
    editor = $('<div />');     // create editor element

Hampei

// keeps the value of formfield set to html contents below target 
window.sync_node_html_to_form_field = function(node, field) {
  var observer = new MutationObserver(function(mutations) {
      field.value = node.innerHTML;
  });
  observer.observe(node, { characterData: true, childList: true, subtree: true });
}

Hampei

# Will render the the show method instead of redirecting when the action is an ajax request.
# Also adds an options xhr_show to render instead of show.
class XhrAwareResponder < ActionController::Responder
protected
  def navigation_behavior(error)
    if get?
      raise error
    elsif has_errors? && default_action
      render action: default_action, layout: options[:layout]
    elsif controller.request.xhr?