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Using Obj-C with MacRuby/Rubymotion

This little post aims to help you to translate Objective-C Blocks into Ruby blocks. Let's start by taking a look at few examples of iOS API call where blocks are used for animations and enumeration

Ruby Lambda Syntaxes:

Im Rubymotion and MacRuby you can use all the Ruby Lambda syntaxes that are:

block = lambda { |param|  ... }

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//
//  AppDelegate.m

#import "AppDelegate.h"
#import "GoogleOpenSource/GTMOAuth2Authentication.h"
#import "MainViewController.h"
#import "SignInViewController.h"

@implementation AppDelegate

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Protocol
------------

Protocol in Objective-C is like interface in Java
Apple tends to favor using subclasses than protocol
NSObject is a class but also a protocol

Category
------------

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What is a Relational Database?
------------------------------

A set of true propositions
Every row in a table is the statement about the truth related to the table
Enforces logical integrity (business rules)
Application independent store (this is the reason why relational database was created)

Why Normalize?
--------------

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# Change this:


...

#!/usr/bin/ruby

require 'osx/cocoa'

# My Script…

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Using Meld merging tool on Mac

1. Install XQuartz

2. Install meld with brew

    brew install meld
   

3. Copy PYTHONPATH

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class String
  def escape_single_quotes
    self.gsub(/'/, "\\\\'")
  end
end

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array.inject{|sum,x| sum + x }

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# Courtesy http://www.allerin.com/blog/?p=186

class ActiveRecord::Base

  def self.skip_callback(callback, &block)

    method = instance_method(callback)

    remove_method(callback) if respond_to?(callback)

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# Taken from http://codesnippets.joyent.com/posts/show/1812

# takes a number and options hash and outputs a string in any currency format
def currencify(number, options={})
  # :currency_before => false puts the currency symbol after the number
  # default format: $12,345,678.90
  options = {:currency_symbol => "$", :delimiter => ",", :decimal_symbol => ".", :currency_before => true}.merge(options)
  
  # split integer and fractional parts 
  int, frac = ("%.2f" % number).split('.')