No Pressure

Mongoid recursively embedding

Tue, 22 May 2012 11:28:55 +0100

This is a note for myself for a project I am actually working on that I thought could be useful to share :)

More info here.

CYCLIC RELATIONS on MONGODB WITH MONGOID

A document can recursively embed itself using recursively_embeds_many, which provides accessors for the parent and children.

class Tag
  include Mongoid::Document
  recursively_embeds_many
  field :name
end

programming = Tag.new(:name => 'programming')
ruby = programming.child_tags.build(:name => 'ruby')
python = programming.child_tags.build(:name => 'python')

programming.child_tags  # [ruby, python]
ruby.parent_tag         # [programming]
python.parent_tag       # [programming]

Updating embedded child objects when the parent object is saved.

Tue, 22 May 2012 11:26:32 +0100

Mongoid has added a tag which automatically makes callbacks for embedded child objects when the parent object is saved.

You can find it at the end of the mongoid documentation on embedding.

class Post
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Paranoia

  embeds_many :comments, cascade_callbacks: true
  accepts_nested_attributes_for :comments
end

"I am truly free only when all human beings, men and women, are equally free. The freedom of other..."

Fri, 18 May 2012 10:16:28 +0100

“I am truly free only when all human beings, men and women, are equally free. The freedom of other men, far from negating or limiting my freedom, is, on the contrary, its necessary premise and confirmation. It is the slavery of other men that sets up a barrier to my freedom, or what amounts to the same thing, it is their bestiality which is the negation of my humanity. For my dignity as a man, my human right which consists of refusing to obey any other man, and to determine my own acts in conformity with my convictions is reflected by the equally free conscience of all and confirmed by the consent of all humanity. My personal freedom, confirmed by the liberty of all, extends to infinity.”

- Mikhail Bakunin - Bakunin on Anarchy

"Do I contradict myself? Very well, then I contradict myself, I am large, I contain multitudes."

Thu, 17 May 2012 15:40:00 +0100

“Do I contradict myself? Very well, then I contradict myself, I am large, I contain multitudes.”

- Whitman

"I find fascinating how people protect the right of the richest for fear of loosing what they..."

Wed, 16 May 2012 15:53:42 +0100

“I find fascinating how people protect the right of the richest for fear of loosing what they don’t have but are told they might get someday…”

- my self :)

"If you go where everybody else is you might just end up doing the same thing… if you think..."

Mon, 14 May 2012 14:44:40 +0100

“If you go where everybody else is you might just end up doing the same thing… if you think about it Bob Marley didn’t go to London or New York to play Rock music, he stayed in Jamaica to invent Reggae…”

- myself :)

Nested hash in ruby

Mon, 14 May 2012 14:42:24 +0100

Ever wondered how to create nested hash in ruby?

Here it is:

1.9.3p125 :001 > a = Hash.new{|h,k| h[k]=Hash.new(&h.default_proc) }

=> {}

1.9.3p125 :002 > a[2][1] = 2

=> 2

1.9.3p125 :003 > a[2][2][3] = 2

=> 2

1.9.3p125 :004 > a[2][2][4] = 5

=> 5

1.9.3p125 :005 > a[3][1][1][1] = 7

=> 7

1.9.3p125 :006 > a

=> {2=>{1=>2, 2=>{3=>2, 4=>5}}, 3=>{1=>{1=>{1=>7}}}}

:) sweet!

Devise + Mongoid + Cancan

Mon, 26 Mar 2012 15:19:49 +0100

I have thought a while about making a summary post about configuring devise + mongoid + cancan for creating accounts and implementing authentication in a rails app.

First of all there are various guides that you can use to get you started. All of them can give you a different insight on the technology and a different perspective and what is needed to accomplish whatever you have in mind :).

So feel free to google for devise + cancan and you end up reading Tony Amoyal’s blog post. It is a very good post description and pointed me toward the right direction.

If you want a different point of view though (also considering that I am using mongoid), here is my dirty summary on how to configure an app that would use these gems:

First of all install devise:

Devise 2.0 works with Rails 3.1 onwards. You can add it to your Gemfile with: gem ‘devise’ or run the bundle command.

After devise has been installed, run the generator:

rails generate devise:install

The generator installs an initializer describing All devise’s configuration options and it is advised to have a look at it. Then add devise to your models using the generator:

rails generate devise MODEL

More details are available here: https://github.com/plataformatec/devise; together with links to some example app that could be extended to suit your needs.

Now let’s install cancan. In Rails 2 you can add it to your Gemfile and or run the bundle command:

gem "cancan"

Continue with using the generator for creating the Ability class for a User:

rails g cancan:ability

Simple as that. You can find out more here.

Now how should you model your User and Admin accounts? You can do this with a single user class, or you can do it with different classes :).

I personally prefer to use different classes to keep the two roles separately.

Hai fatto parte del POuL un po' di tempo fa? :-)

Sat, 10 Mar 2012 17:57:15 +0000

Si :)

Anche tu? Ci conosciamo? Il mio nick era Hiromi.

How to load a feed with Google Feed API and JQuery

Tue, 21 Feb 2012 10:13:00 +0000

Here is a quick and dirty way to load a xml feed with Google Feed API with Jquery. Enjoy!! :)

First step include the necessary external calls:

Second step your javascript function:

* How to load a feed via the Feeds API.

google.load(“feeds”, “1”);

// Our callback function, for when a feed is loaded.

function feedLoaded(result) {

if (!result.error) {

// Grab the container we will put the results into

var container = $(“#latest”);

$(“#latest”).empty();

html = “<div><ul>”;

// Loop through the feeds, putting the titles onto the page.

// Check out the result object for a list of properties returned in each entry.

// http://code.google.com/apis/ajaxfeeds/documentation/reference.html#JSON

for (var i = 0; i < result.feed.entries.length; i++) {

var entry = result.feed.entries[i];

html += “<li>”

+ entry.title

+ “</li>”;

}

html += “</ul></div> “;

$(“#latest”).append(html);

}

function OnLoad() {

// Create a feed instance that will grab Digg’s feed.

var feed = new google.feeds.Feed(“https://gdata.youtube.com/feeds/api/users/devinsupertramp/uploads”);

// Calling load sends the request off. It requires a callback function.

feed.load(feedLoaded);

}

google.setOnLoadCallback(OnLoad);

</script>

Third and last step, add a div into your code to contain the results:

Super quick!! Enjoy!!

Quick and dirty search in Rails

Wed, 30 Nov 2011 17:32:08 +0000

Ever wondered how to quick have a search function in your rails app?

Here is a super quick and maybe a lil dirty way to achieve so.

First step:

The view

<p><%= form_tag("/searches", :method => "get") do %>

<%= text_field_tag :keywords, params[:keywords] %> </p>


       <p>  <%= submit_tag("Search") %>
           <% end %>
       </p>

Second step:

search.rb model (app/models)

class Search < ActiveRecord::Base


  def self.find_results(search)
    if search
      Item.find(:all, :conditions => ['name LIKE ?', "%#{search}%"])
    else
      Item.find(:all)
    end
  end
end

Third step:

searches_controller.rb (app/controllers)

class SearchesController < ApplicationController


  def index
    @results = Search.find_results(params[:keywords])
  end
end

Fourth step:

index.html.erb (app/views/searches)

<% @results.each do |result| %>


             <p><%= result.name %></p>

Done :)

Just don’t forget to add resources :searches, :controllers => ‘searches’ to your routes.rb!

Ruby headaches pills

Mon, 17 Oct 2011 16:33:09 +0100

If:

script/rails generate controller Hello

Is failing, try to remember that you have probably installed more than one version of rails in your history, so you might need to call:

rvm use 1.9.1 —default :)

"The future is distributed!"

Thu, 15 Sep 2011 14:23:33 +0100

“The future is distributed!”

Hire the hackers!

Wed, 14 Sep 2011 10:53:00 +0100

Hire the hackers!

ckck: Control panel at IBM. San Jose, California, circa...

Tue, 06 Sep 2011 18:39:58 +0100

ckck:

Control panel at IBM. San Jose, California, circa 1958.

Photograph by Arnold Del Carlo.

Home abroad

Tue, 06 Sep 2011 13:18:56 +0100

Home abroad:

I still treasure my memories of two weeks spent in Buenos Aires almost 3 years ago, and this article has brought all of them back again :)

"Work smarter, play harder"

Mon, 05 Sep 2011 09:19:30 +0100

“Work smarter, play harder”

- Never got why we have to work hard… ;)

"Schmidt says definitively: the next generation of leaders and startups to emerge will involve..."

Fri, 02 Sep 2011 12:53:31 +0100

“Schmidt says definitively: the next generation of leaders and startups to emerge will involve mobile, local, and social. He explains that we’ve exhausted the limits of the PC as a platform, the future will be mobile first.”

- Reinvent the future, everything else will follow.

Dublin sunset

Sat, 27 Aug 2011 15:53:26 +0100

Dublin sunset

Creative destruction

Fri, 19 Aug 2011 13:17:37 +0100

From Capitalism, Socialism and Democracy (New York: Harper, 1975) [orig. pub. 1942] by Joseph A. Schumpeter, pp. 82-85:

Capitalism, then, is by nature a form or method of economic change and not only never is but never can be stationary. And this evolutionary character of the capitalist process is not merely due to the fact that economic life goes on in a social and natural environment which changes and by its change alters the data of economic action; this fact is important and these changes (wars, revolutions and so on) often condition industrial change, but they are not its prime movers. Nor is this evolutionary character due to a quasi-automatic increase in population and capital or to the vagaries of monetary systems, of which exactly the same thing holds true. The fundamental impulse that sets and keeps the capitalist engine in motion comes from the new consumers, goods, the new methods of production or transportation, the new markets, the new forms of industrial organization that capitalist enterprise creates.