In MVC architecture, one of the great perks of routing is once you create the resourceful route, you usually don’t have to think about it again. Set up your actions and views, and you’re ready to go. Sencha Touch has brought the power of routing to their mobile JS framework, giving you an easy way to declare “URLs” which point to controllers and actions, but it does more than that, including abstracting History logic into the Dispatcher so that any Ext.redirect will automatically set the URL in the Ext.History space. You can read all you want about the Router and Dispatcher on Sencha’s site, but one thing I missed was the ability to declare a resourceful route. With Rails (3) you get to simply say “resources :transfers” and it will automagically recognize your index, create, and other routes for you. Thus, I added this handy little patch with 2 helpful methods (resources and alias), which allow me to do more than just “connect”, as so:

Ext.Router.draw(function(map) {
  map.connect('welcome', { controller: 'welcome', action: 'index' });
  map.connect('dashboard', { controller: 'dashboard', action: 'show' });
  map.connect('login', { controller: 'user_sessions', action: 'new' });
  map.connect('logout', { controller: 'user_sessions', action: 'destroy' });

  map.resources('transfers');
  map.resources('payments');
  map.resources('messages');
  map.resources('accounts');

  map.alias('bill_pay', 'payments');
  map.alias('message_center', 'messages');

  // more fluffy stuff...
});

Note the “map.resources” and “map.alias” lines, then check out the code below that does the work. Above, the map.resources(‘transfers’) line will produce 8 routes by default, including ‘transfers/index’, ‘transfers/new’, etc.

Get the Gist…

As you can see, the resources function simply generates the resourceful routes for you. The alias function is a convenience method really which, well, aliases a named route to another URL. So in this example, Ext.redirect(‘bill_pay’) is identical to Ext.redirect(‘payments’), both landing you in the index action of the payments controller. That’s it… feel free to use/comment at will. Happy coding!

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Ext.Dispatcher.on('before-dispatch', function(interaction) {
  if(Ext.isFunction(interaction.controller.beforeFilter)) {
    return interaction.controller.beforeFilter.call();
  };
  return true;
});

Ext.Dispatcher.on('dispatch', function(interaction) {
  if(Ext.isFunction(interaction.controller.afterFilter)) {
    return interaction.controller.afterFilter.call();
  };
  return true;
});

In my application setup, I have a function (requireUser) that handles my logic for requiring that a user be logged in:

Ext.regApplication({
  // code, code, code...
  loggedIn: readCookie('user_credentials') || false,
  requireUser: function() {
    if(app.loggedIn) return true;
    app.flash.warning = 'Please login to continue.';
    Ext.redirect('login');
    return false;
  },
  flash: {
    notice: '',
    warning: ''
  }
});

Then in each of the files I want to require a user (or run some other before/after filter logic) I have something like so…

Ext.regController('accounts', {
  beforeFilter: app.requireUser,
  model: 'Account',
  index: function(options) {
    app.views.viewport.setActiveItem(
      app.views.accountsList, options.animation
    );
  },
  // other actions here...
});

For reference on Ext.Controller and Ext.Dispatcher, check out the Sencha Touch docs

Since it is Sencha on Rails, I feel like this approach adds a nice, seamless integration. Feel free to use, share, comment at will. Happy coding!

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When the first-gen iPhone was released, it was flashy (although lacked Flash itself) and new; it opened the world’s eyes to the potential of mobile experience (I will punt on the use of the word “technology” here because, let’s be honest, the original iPhone did not match up to other smart phones on the market at the time). However, by supplying an open SDK for application development and presenting users with a slick, user-friendly interface, it rapidly became a fad… although I’m still uncertain as to the reason behind the massive amount of loyalty and defensiveness that goes along with owning an iPhone.

One theory I have for why the launch was so intense is this: For many years after Apple’s Mac line was completely revamped, there was always an elite status associated with Apple products, simply because at the time, Apple was only known for making computers – really expensive ones. Then came the iPod which cost significantly more than (roughly double) other MP3 players, but it looked better and if you had iTunes, you were able to very easily purchase and download music, then sync it to the device, essentially taking your Library with you wherever you go. Rhapsody eventually attempted this same business model, but the iPod precedent had been set. The story goes on to say that next was the iPhone, then the iPad but we’re aware of what’s gone down in the last 3 years so I’ll spare the details. So now we’ve seen a trend in the last decade… iPod, iPhone, iPad, each of them continue to blow the competition away in terms of market share. But, why? They’re sleek, sexy and they scream “status”. For the same reason that BMWs and Lexus’ are popular and longed-after, so are Apple’s iProducts. In the U.S., we’re known for living outside of our means, which means if a sparkly new toy costs less than $500, you *probably* have a credit card with at least that much available to spend. So if you could carry around a status symbol in your pocket in exchange for … well, nothing up front … why wouldn’t you? Right? At least that explains why Apple’s handheld devices have caught such wind, while their stationary counterparts are still no match for PCs.

I own Macs because I believe in the quality of the computer and doing graphic design and software development is so much faster, especially when you work with Linux, there’s minimal knowledge transfer needed when switching between environments. I own an AppleTV because dollar for dollar, it’s cheaper than cable considering I only watch about 3 TV shows and on rare occasion rent a movie. PLUS, I can use it to stream music from my iMac which alleviates the previous requirement of getting up and putting a different CD in the stereo. So I feel those purchases are justified. My iPod Nano was a birthday gift 2 years ago and I think I’ve used it a total of 7 times, and although it’s shiny and pink and in perfectly good condition, it’s essentially useless but I don’t think it’s heavy enough to be a paperweight. As for the iPad, didn’t buy that one either, was a hand-me-down from the CEO of my company who badly needed the 3G version and unloaded his completely antiquated, way uncool WiFi version down to me. I must say, I have taken quite a liking to the iPad, I even cuddle it to sleep at night playing WWF and Angry Birds – because I’m just *that* nerdy. Nonetheless, iPhone iLack.

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require 'test_helper'

class MailerTest < ActionMailer::TestCase

  CHARSET = 'UTF-8'

  context "Forgetting a password" do
    setup do
      @user = User.create(valid_user_params)
      @expected = Mail.new
      @expected.content_type = 'text/plain'
      @expected.charset = CHARSET
      @expected.mime_version = '1.0'
    end

    should "send password reset instructions" do
      @expected.from    = "from@example.com"
      @expected.to      = @user.email
      @expected.subject = "Some Fancy Subject"

      assert_equal @expected, Mailer.password_reset_instructions(@user)
    end
  end
end

I’m using Shoulda with TestUnit, but in theory this should work with rspec, etc. Thanks to http://kpumuk.info/ruby-on-rails/testing-mailers-with-rspec/ for giving me a starting point… There’s definitely more you can add, like testing for the body content, but really this was all I needed for the purposes of this test.

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First things first, you should be sanitizing your code prior to storage. Worried about someone adding JS to your public blog and breaking the site? Easy solution, throw away the <script> tag before writing to the db. There are plenty of tools to help with this, xss_terminate being one of them, there are even built-in Rails sanitizers. If you do it right on the way in, you won’t have to worry about it on the way out. Ok, so let’s say you potentially miss something? It happens, no one is perfect. That’s the perfect case to use escape trickery ( i.e. h() ) in the areas where you might be worried about your output.

In general, if you develop applications that resemble ones I build in anyway, you have more HTML output that *doesn’t* need to be sanitized than does. Sorry to whichever genius thought it would be a great idea to escape everything, but you made a bad decision. It’s okay, have a beer, wallow in your sorrows and then give users the option to turn this off. In the mean time, it’s easy to disable it yourself.

In config/initializers create a file, call it whatever, I called mine output_buffer.rb and all you need is:

class Object
  def html_safe?
    true
  end
end

class String
  def html_safe?
    true
  end
end

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Basically what happens is if a video has a YouTube ID, then go get the thumbnail image and the original MPEG file from YouTube and convert it to flv before saving. If the user uploads a video, use ffmpeg to grab a still of the first frame to use as the thumbnail, then convert it to flv and save it.

I present thee Video model. (Unfortunately this was so long ago, I was using attachment_fu… maybe Paperclip would have helped a bit.)

class Video < ActiveRecord::Base
  include AASM

  aasm_column :state
  aasm_initial_state :pending
  aasm_state :pending
  aasm_state :converting
  aasm_state :converted, :enter => :set_new_filename
  aasm_state :error

  aasm_event :convert do
    transitions :from => :pending, :to => :converting
  end

  aasm_event :converted do
    transitions :from => :converting, :to => :converted
  end

  aasm_event :failure do
    transitions :from => :converting, :to => :error
  end

  def get_yt_video_data
    uri = URI.parse("http://www.youtube.com/get_video_info")
    post_args = { 'video_id' => self.url }
    res, data = Net::HTTP.post_form uri, post_args
    b = res.body
    CGI::parse(b) ## return a hash of k=>v pairs
  end

  def get_yt_video_thumb
    get_yt_video_data["thumbnail_url"].first
  end

  def get_yt_video_duration
    seconds = get_yt_video_data["length_seconds"].first.to_i ## format this better... seconds/60 = mins/60 = hours ... hh:mm:ss
    total_minutes = seconds / 1.minutes
    seconds_in_last_minute = seconds - total_minutes.minutes.seconds
    "#{total_minutes}:#{seconds_in_last_minute}"
  end

  def get_yt_embed_url
    return CGI::escape("#{public_filename}") unless self.url.present?
    data = get_yt_video_data
    fmt = '';
    fmt_map = data["fmt_map"]
    a = fmt_map[0..2]
    if a == '18/'
      fmt = '18'
    elsif a == '22/'
      fmt = '22'
      break
    end
    token = data["token"]
    uri2 = URI.parse("http://www.youtube.com")
    args2 = {:video_id => url, :t => token, :fmt => fmt }
    qstr = "video_id=#{url}&t=#{token}&fmt=18"
    res = ""
    Net::HTTP.start(uri2.host, uri2.port) {|http|
      res = http.head("/get_video?#{qstr}")
    }
    CGI::escape("#{res.header['Location']}")
  end

  protected

  def after_create
    return true if url.present?
    convert
  end

  def convert
    self.convert!
      spawn do
        success = system("ffmpeg -i #{full_filename} -ar 22050 -s 480x320 -f flv -y #{full_filename}.flv")
        if success && $?.exitstatus == 0
          self.converted!
        else
          self.failure!
        end
     end
  end

  def create_thumbnail
    system "ffmpeg -i #{full_filename}.flv -s 120x90 -vframes 1 -f image2 -an #{full_filename}.jpg"
  end

  def set_new_filename
    create_thumbnail
    update_attribute(:filename, "#{filename}.flv")
    update_attribute(:content_type, "application/x-flash-video")
    update_attribute(:width, "480")
    update_attribute(:height, "320")
  end

end

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First, we have a template that looks a little something like this:

<div id="events-calendar">
  <%= render :partial => "events/calendar" %>
</div>
<% form_tag events_path, :id => "update_dates", :name => "update_dates" %>
  <%= label_tag :start_date %>
  <%= text_field_tag  :start_date %>
  <%= label_tag :end_date %>
  <%= text_field_tag  :end_date %>
  <%= submit_tag "Go!" %>
<% end %>
<div id="events-list">
  <%= render :partial => "events/list" %>
</div>

Now, in the past using RJS, this was a very easy thing to do, you just did something to the effect of:

render :update do |page|
  page.replace "events-calendar", :partial => "events/calendar"
  page.replace "events-list", :partial => "events/list"
end

Also, note that I could put all of this in a partial of it’s own and re-render the whole thing, but for all intents and purposes of the app I’m working on, that doesn’t cut it since I’d have about 6 partials that look very similar to this one (for example, I have a view that just has the date inputs and a list that should update, a view that has the calendar and a form for editing an event, etc etc).

In this example, we want when the dates are updated, the calendar and the list of events should refresh in a single AJAX call, without the use of RJS. There are a plethora of reasons to break your RJS habit sooner, rather than later… I tend to dislike it for the sheer fact that it’s tied to one JS library or another, whereas using external JS means if I decide I want to use YUI instead of jQuery, the only thing I have to change is my JS function to do a YUI-style AJAX call and DOM update. No Rails plugins, messing with controllers or RJS templates, etc. etc. Plus, it looks so much cleaner when your controllers don’t have a bunch of render :updates in them.

On to the good stuff… In my application.js (or wherever you fancy), I have the following:

$.ajaxSetup({
  beforeSend: function(xhr){ xhr.setRequestHeader('Accept', 'text/javascript') }
});

$(document).ready(function() {
  $('form#update_dates').submit(function() {
    $.get($(this).attr('action'), $(this).serialize(), function(data, status) {
      $('#events-calendar').html(data.calendar);
      $('#events-list').html(data.list);
    }, 'json');
    return false;
  });
});

I’m setting up the beforeSend AJAX option because jQuery doesn’t communicate AJAX calls to Rails as being of JS format, so if you don’t have this, you’ll likely end up in your format.html . You’ll need to know the appropriate AJAX calls for your library, the reason I’m using $.get instead of $.ajax with a dataType: ‘json’ is that I only care about having one callback. Also, we’re asking for a JSON result, but I’m not using $.getJSON  because I’ve had some issues in the past in Firefox with the getJSON method. If you needed to handle errors as well as successes, you would need to use $.ajax with the error and success callbacks.

Okay, so now let’s look at the data that Rails is going to give us before we write the callback. We know we want to send back 2 partials, and we don’t want to tie any javascript or DOM knowledge into this, so here’s the approach. We are using the Rails helper method <%= events_path %> to direct us to our index method, so we’ll use respond_to to detect the javascript call.

class EventsController < ApplicationController

  def index
    ## do your logic here, for example:
    if params[:start_date].present? and params[:end_date].present?
      @events = Event.all.between(params[:start_date], params[:end_date]) ## between would just be a named scope that adds date conditions
    else
      @events = Event.all
    end

    respond_to do |format|
      format.html # render default index.erb
      format.js {
        render :json => { :list => render_to_string(:partial => "events/list"), :calendar => render_to_string(:partial => "events/calendar") }.to_json
      }
    end
  end

end

So there are a few things this controller method is doing that are outside the scope of this article, such as using named_scopes, the respond_to block, and render_to_string — all of which can be found documented in the Rails API reference. The main thing we’re concerned with here is rendering json so that our keys are usable within our javascript. They are not the same as the id of the div since your controller shouldn’t care what your DOM looks like. And voila, it really is that easy, simple and clean to build tons of AJAX into your app without making it overly messy.

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Credits to:

Facebook: http://cootelibeau.files.wordpress.com

Github: http://github.com/blog/47-new-fluid-icon

Mint and Pivotal: http://sneaky.me/2008/11/fluid-app-icons-for-mint-and-pivotal-tracker/

Campfire: http://www.flickr.com/photos/indiekid/2555128022/

Gmail: http://iconexpo.com/

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Now, it’s my turn to give back:

I wanted something completely reusable, simple and easy-to-read that would allow me to iterate over a collection, whilst producing an html block of content specific to the type of object in the collection. Understand? No. Okay then, here you go:

BEFORE

<% if @blog_posts && @blog_posts.size > 0 %>
  <% @blog_posts.each do |blog_post| %>
    <div class="blog_post">
      <%= link_to blog_post.title, blog_post %>
      <%= truncate blog_post.content, :length => 500 %>
    </div>
  <% end %>
<% end %>

That’s a lot of ugliness, logic, just — ugh.

Now, mind you, I am fully aware of the ability to do partial rendering to achieve the same affect … i.e.

<%= render :partial => @blog_posts %>

But, I have some objects that don’t even have controllers much less views, especially when they’re associated to other things (like photos for instance … no controller, no views, but I’d like to render all of the photos for a certain object)

Introduce collection_content_each_tag.

def collection_content_each_tag(collection, tag_name=:div, &block)
  return unless collection && collection.size > 0
  collection.each do |item|
    concat("<#{tag_name.to_s} class=\"#{item.class.name.underscore}\">")
    concat(capture(item, &block))
    concat("</#{tag_name}>")
  end
end

NOTE: Only in recent versions of Rails does #concat not want you to pass the binding argument — If you’re running older versions of Rails, make sure that on each of the #concat methods above, you add block.binding as a second argument.

So what is this method doing? Well I’ll tell you. Say for instance you have a collection of photos and you want to generate a div containing each photo and its caption.

AFTER

<% collection_content_each_tag @photos do |photo| %>
  <%= image_tag photo.public_filename(:thumb) %>
  <%= photo.caption %>
<% end %>

The method loops over @photos creating a div, (defaults to :div, but you could pass :span, :p, whatever as your second arg), and generates your html tag with your block elements inside. The photo block argument in this example represents an item in the @photos collection, which gets passed to the block. So our output is:

<div class="photo">
  <img src="/photos/0001/photo_1_thumb.jpg"/>
  Is this not the most gorgeous flower you've ever seen?
</div>

<div class="photo">
  <img src="/photos/0002/photo_2_thumb.jpg"/>
  A panda loose in Brooklyn.
</div>

EXTEND IT

Add an id attribute on your tag with the object id in it:

def collection_content_each_tag(collection, tag_name=:div, &block)
    return unless collection && collection.size > 0
    collection.each do |item|
      concat("<#{tag_name.to_s} id=\"#{item.class.name.underscore}-#{item.id}\" class=\"#{item.class.name.underscore}\">")
      concat(capture(item, &block))
      concat("</#{tag_name}>")
    end
end

Would give you:

<div class="photo" id="photo-1">
  <img src="/photos/0001/photo_1_thumb.jpg" />
  Is this not the most gorgeous flower you've ever seen?
</div>

Maybe someone’s done this before, who knows. But that’s it, simple, reusable, and easy-to-read.

Happy coding!

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def hash_intersect_min(*hashes)
  hashes.inject(hashes.pop.dup) { |i,h| i.delete_if { |k,v| hv=h[k]; next true unless hv; i[k]=hv if hv<v; false }; i }
end

So the following:

hash_intersect_min({:a => 1, :d => 2, :k => 2, :j => 6}, {:k =>1, :a => 4, :j => 4}, {:e => 4, :k => 2, :d => 4, :j => 9})

Produces:

{:k=>1, :j=>4}

I’m completely aware of the extreme triviality this introduces to most programming, but ya know what… sometimes you need quirky crap to get you through the day. Happy coding!

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