Need to pass a Ruby Array to a Javascript Array?
Here’s a little gem I found a while ago that I’m reusing in my current project.

>> a_ruby_array = ["one", "two", "three"]
=> ["one", "two", "three"]
>> "['#{a_ruby_array.join('\',\'')}']"
=> "['one','two','three']"

Here’s a little trick I found when handling multiple nested models in a form that require validations for each model.

Spec time. For example, we have a model, Author, which has_many Books and has_many Magazines. Book and Magazine has validations. On a single page, we create a three forms for Book, Magazine, and Author. There is also an option select that a user can choose if the Author has a Book or a Magazine.

Pretty straight forward. Let’s do some code.

#models/author.rb
class Author < ActiveRecord::Base
  has_many :books
  has_many :magazines

  accepts_nested_attributes_for :books
  accepts_nested_attributes_for :magazines

  validates_presence_of :name
end

#models/book.rb
class Book < ActiveRecord::Base
  belongs_to :author
  validates_presence_of :title, 
                        :genre
end

#models/magazine.rb
class Magazine < ActiveRecord::Base
  belongs_to :author
  validates_presence_of :title, 
                        :genre
end

Basic model setup with validations and accepts_nested_attributes_for. More info on that can be found in the Ruby on Rails API – Nested Attributes.

Moving on to the form setup..

#views/authors/new.html.erb
<% form_for @author do |f| %>
<%= f.error_messages %>
  <p>
    <%= f.label :name %><br />
    <%= f.text_field :name %>
  </p>
  <p>
    <%= f.radio_button("media_type", "book" %><%= f.label :media_type_book, 'Book' %> [?]
    <%= f.radio_button("media_type", "magazine" %><%= f.label :media_type_magazine, 'Magazine' %> [?]
  </p>
  <% f.fields_for :books do |book| %>
    <p>
      <%= book.label :title %><br />
      <%= book.text_field :title %>
    </p>
    <p>
      <%= book.label :genre %><br />
      <%= book.text_field :genre %>
    </p>
  <% end %>

  <% f.fields_for :magazines do |magazine| %>
    <p>
      <%= magazine.label :title %><br />
      <%= magazine.text_field :title %>
    </p>
    <p>
      <%= magazine.label :genre %><br />
      <%= magazine.text_field :genre %>
    </p>
  <% end %>
  <%= f.submit 'Submit' %>
<% end %>
  

That sets up the form with the nested model, now for the controller code.

#controllers/authors_controller.rb
class AuthorsController < ApplicationController
  def new
    @author = Author.new
    books = @author.books.build #this builds the nested form in the view
    magazines = @author.magazines.build #this builds the nested form in the view
  end

  def create
    param_hash = params[:author]
    if params[:author][:media_type] == "book"
      param_hash.delete("books_attributes")
    elsif params[:author][:media_type] == "magazine"
      param_hash.delete("magazines_attributes")
    end
    @author = Author.new(param_hash)
    @author.save
  end
end

Instead of passing the params straight to Author.new, it’s put into a hash variable. Then the params get checked for a title and genre, if empty delete the key from the hash and pass to Author.new. Activerecord wont see the book param and will skip the validations for it.

Is it me or do 90% of the Android apps look similar to Windows 3.1 software?

I’ve been developing an Android app over the past few weeks and I noticed that the GUI quality for Android apps is lacking. I’m pretty sure this is do to the lack of filtering that Google does, which Apple requires.

While looking through dozens and dozens of apps, I came across comments such as, “if this looked better, i’d give it a 5 star.”

That got me thinking about this app I’m currently working on. If I make this app beautiful, I could probably sell it for a $1 more!

I believe that a majority of app users, iPhone or Android, really want pretty interfaces over anything else.