adambeynon

** Draft **

I develop and maintain several apps written using Opal. These vary in their size, and vary in their usage. Each of these apps use rails as a backend. Some use html rendered through rails, and some use json rendered by rails. But in each case, these apps are tied in logic to the backend, and indeed share model logic between client and server.

• Don't Repeat Yourself.
• Shared modules - code once, use client & server
• RSpec - write tests once, run client & server
• Maintainability - Opal, questions about maintenance. Offset against maintaining ruby + coffeescript versions of same code
• Overhead - filesize vs. context of code, is a little filesize worse than maintaing 2 code bases
• Opal -> js, no different from coffeescript/es6 -> js

adambeynon

Opal.build_manifest do
  # find application.rb in our load path and compile that (and all dependencies)
  compile "application"

  # we want all templates included, but use our custom haml (react.js style) parser
  each_glob "templates/**/*.haml" do |file|
    special_haml_compile file
  end

  # compile these default gems that might not be required inside application.rb

adambeynon

Router.map do
  route :index do
    index :inbox_stats
    route 'message/:id'
  end
  
  route :calendar
  index :dashboard
end

adambeynon

class AvailabilityChecker
  def initialize(reservation)
    @reservation = reservation
  end

  def available?
    if @reservation.new_record?
      new_record_available?
    elsif @reservation.unit_id_changed?
      update_unit_available?

adambeynon

// ugly code from beautiful code
//    object.foo(1, 2, 3)

(_a = object, _a.$foo || $mm)(_a, 'foo', 1, 2, 3);

adambeynon

module Vienna
  class BaseBinding
    def initialize(view, context, node, attr)
      @view = view
      @context = context
      @node = node
      @attr = attr

      setup_binding
    end

adambeynon

require 'opal-jquery/version'

if RUBY_ENGINE == "opal"
  require 'opal-jquery/window'
  require 'opal-jquery/document'
  require 'opal-jquery/element'
  require 'opal-jquery/event'
  require 'opal-jquery/http'
  require 'opal-jquery/kernel'
end

adambeynon

Sending method no args

recv.foo

rb_send0(recv, 'foo');

function rb_send0(recv, mid) {

adambeynon

RACSignal *nameSignal = [RACObserve(self, someManagedObject.name) distinctUntilChanged];
RAC(self, someTextField.text) = [nameSignal deliverOn:[RACScheduler mainThreadScheduler]];

signal = observe(self, "some_managed_object.name")
signal.on_value { |val| self.some_text_field.text = val }

adambeynon

The idea is that we are binding an attribute cart_empty on the current object to get updated when some remote attribute on some other object changes. This results in a method call current_obj.cart_empty = new_value.

bind(:cart_empty).to observe(@cart, :empty?)

bind(:cart_empty).to @cart.observe(:empty?)

bind :cart_empty, @cart.observe(:empty?)