Posts

Exploring some string methods

It's important to be able to manipulate strings effectively in Ruby. Here are some details about some code I wrote to convert phone numbers that arrive in all different formats to a standard "555-555-5555" format that an API I'm working with expects.

In Ruby On Rails By Leigh Halliday August 20, 2015

Leigh Halliday

A Stack in Ruby using Linked Lists

A Stack is an abstract data type in programming which has a variety of uses. The basic premise of a Stack is that you can add a new value to the end (pushing), and you can remove the last value off of the end. This is referred to as LIFO - Last In First Out. Today we'll explore how to create a Stack in Ruby using Linked Lists.

In Ruby On Rails By Leigh Halliday July 03, 2015

Leigh Halliday

Weighted Quick Union & Quick Find Algorithm in Ruby

We are going to explore a Ruby implementation of the Weighted Quick Union & Quick Find algorithm. This is an algorithm used to find if there is a connection between two nodes. First we explore the simplest solution and then make it more performant.

In Ruby On Rails By Leigh Halliday June 29, 2015

Leigh Halliday

Showing similar results in Postgres

If you search "trgrams in pstgres" in Google, you'll get results for "trigrams in postgres". To say that is useful is an understatement! Recently at work I wanted to search a table of tags, but I wanted to account for spelling mistakes. Just because the user is 1 letter off doesn't mean I shouldn't give them a meaningful search result. We are going to use the Trigram feature in Postgres to help us achieve this.

In Databases By Leigh Halliday June 25, 2015

Leigh Halliday

Avoid race conditions in Rails with Postgres locks

Earlier this year a programmer reported that he discovered a race condition bug in the Starbucks system which allowed him to essentially have an unlimited giftcard balance. It's obviously a problem that can have some serious financial implications. In this article we explore how to handle race conditions in Rails.

In Ruby On Rails By Leigh Halliday June 16, 2015

Leigh Halliday

CORS in Phoenix

There are some special considerations you have to think of when creating an API that will be consumed by Angular (or any other front-end framework). One of these is security related, specifically around the issue of CORS. This article is about handling CORS in Phoenix.

In Elixir By Leigh Halliday June 11, 2015

Leigh Halliday

Recursion in Elixir

I recently wrote an article on Recursion in Ruby, and this is meant to be its Elixir counterpart. It will provide a way to compare solving the same problems in both languages and a chance to talk about some of their differences.

In Elixir By Leigh Halliday June 01, 2015

Leigh Halliday

Recursion in Ruby

Recursion in computer science is a method where the solution to a problem depends on solutions to smaller instances of the same problem (as opposed to iteration). Let's take a look at how recursion is done in Ruby and how it compares to iterative solutions.

In Ruby On Rails By Leigh Halliday May 26, 2015

Leigh Halliday

FizzBuzz in Elixir

FizzBuzz is a programming quiz you always hear about being used in interviews... to separate those who have basic programming knowledge from those who don't. I'm going to use it as the basis for my first article about Elixir, a great functional programming language which has a very similar feel to Ruby.

In Elixir By Leigh Halliday May 19, 2015

Leigh Halliday

My solution to #5 Software Engineer challenge

I've been programming professionally for over 10 years, and I think it's ridiculous to expect or assume that everyone should be able to do specific kinds of "trick" problems that most likely will never come up except under very specific conditions in the workplace, depending where you work. That being said, I wanted to give it a try... it never hurts to practice and get some experience working on a new problem.

In Ruby On Rails By Leigh Halliday May 11, 2015

Leigh Halliday

Object hierarchy in Ruby

As a way to better understand how Ruby works, I started to dive into how object hierarchies work in the language. We're going to be covering the default ancestry chain in Ruby, how to create your own ancestors, and what the base level objects in Ruby actually do.

In Ruby On Rails By Leigh Halliday May 06, 2015

Leigh Halliday

Requiring Uniqueness in Rails

It's often the case that you want to ensure that you've got uniqueness in your data. You only want an email address to be used once... otherwise what would happen when that person tries to log in? Which user account would you log in with? Rails has an easy way to handle this, but the problem is that it isn't enough.

In Ruby On Rails By Leigh Halliday April 30, 2015

Leigh Halliday

Where is this method defined?

Today I was trying to write a test for a method, and I was expecting certain behaviour that I definitely wasn't getting. Why was this method returning me a valid value when it surely should be failing? Ruby provides a very useful object that allows you to dig into the details about your methods. You can find out where the method is defined, who owns it, and how many parameters it receives, among other things.

In Ruby On Rails By Leigh Halliday April 23, 2015

Leigh Halliday

Savon - SOAP that doesn't leave you feeling dirty

Depending on your field, and perhaps your age, you may not have ever worked with SOAP before. Most APIs these days communicate via RESTful JSON APIs. You're most likely familiar with these if you work with Angular or Ember, or if you've connected to the API of a modern website (Twitter, Shopify, even the New York Times). SOAP APIs work in XML, both the request and the response. Unlike most JSON APIs where you work with HTTP verbs (get, post, put, delete) with query or post variables, the entire SOAP request is in the body, in a big hunk of XML.

In Ruby On Rails By Leigh Halliday April 17, 2015

Leigh Halliday

Ruby Metaprogramming - Method Missing

Method missing is a method that ruby gives you access inside of your objects a way to handle situations when you call a method that doesn't exist. It's sort of like a Begin/Rescue, but for method calls. It gives you one last chance to deal with that method call before an exception is raised. Here we will explore how it works and provide some examples of different ways to use method_missing.

In Ruby On Rails By Leigh Halliday April 08, 2015

Leigh Halliday

Ruby Metaprogramming - Creating Methods

In this post I'll be discussing another aspect of metaprogramming in Ruby. The ability to create methods dynamically, during runtime. There are many reasons to do this, but one of them is to allow you to write generator methods to help you avoid writing repetitive code.

In Ruby On Rails By Leigh Halliday April 02, 2015

Leigh Halliday

Ruby Introspection - Metaprogramming

Introspection in general terms means to look inward. Humans can perform introspection, maybe questioning why we made a certain decision or finding out what makes us happy, and Ruby too can perform introspection.

In Ruby On Rails By Leigh Halliday March 21, 2015

Leigh Halliday

Creating a Ruby DSL

DSLs (Domain-specific language) are used heavily in Rails, but have you ever attempted to understand the concepts of them and tried creating your own? In this article I explore Blocks, DSLs and touch on a bit of meta-programming too!

In Ruby On Rails By Leigh Halliday March 14, 2015

Leigh Halliday

Intro to MongoDB for Postgres developers

MongoDB is an object or document based database... in other words, a NoSQL database. This puts it in contrast to databases such as MySQL, PostgreSQL, or SQLite, who store their data relationally in a tabular format. MongoDB stores its data in JSON-style documents. If you're familiar with JSON, you'll already be familiar with how MongoDB stores its data.

In Databases By Leigh Halliday March 07, 2015

Leigh Halliday

Why doesn't my code work outside of Rails?

Have you ever dealt with a NoMethodError exception for code that worked fine in Rails? There is a good chance that is because you were depending on some methods that Rails monkey-patched into core Ruby classes. This article provides an overview on monkey-patching, what Rails has monkey-patched, and some tips and suggestions.

In Ruby On Rails By Leigh Halliday February 20, 2015

Leigh Halliday

What is Rack?

Whether you're in the market for creating your own Ruby framework or whether you just want to gain a deeper understanding of how Rails works, it's a good thing to know Rack. Rack provides a minimal but standard interface for webservers to communicate with frameworks built in Ruby.

In Ruby On Rails By Leigh Halliday February 14, 2015

Leigh Halliday

Tree Structures in your Rails models

Tree structures are incredibly useful for creating vertical hierarchies in your data. They are for when you need to store categories, org structures, family trees, etc. Did you know there are many different ways to implement tree structures in Rails? Each has benefits and drawbacks, and in this article we'll explore the differences between them. The 3 patterns we'll investigate are: Parent-child, materialized path, and nested set.

In Ruby On Rails By Leigh Halliday February 07, 2015

Leigh Halliday

8 tips on how to choose a technology

How do you make the decision to choose a technology or switch from one to another? When deciding on which technologies to focus your time and energy on to learn, or whether it makes sense to use one over another on any given project, it comes down to a number of different factors. Here are some of the different reasons for choosing one technology over another.

In Software Development By Leigh Halliday February 07, 2015

Leigh Halliday

Embracing change and choosing your identity

How do you identity yourself in terms of your profession/title? How do you feel when faced with change? This is a brief story of making the change from developing most things in PHP to now feeling most comfortable using Ruby.

In Software Development By Leigh Halliday February 07, 2015

Leigh Halliday

When your Rails app slows to a crawl

Hi, Leigh, are you busy? The website is no longer responding... can you investigate? A phone call nobody really likes to receive on a Saturday. No need to fear, after about an hour and a half of work the site was back up. Let's investigate some common issues that slow Rails applications down and how to solve them.

In Ruby On Rails By Leigh Halliday February 01, 2015

Leigh Halliday

Implementing Ruby's Collect Method

Collect allows you to transform each element of your collection object (Array, Hash, or your own object) into something else, ending up with an Array. I wanted to create my own collect method to see how it is implemented.

In Ruby On Rails By Leigh Halliday January 26, 2015

Leigh Halliday

Implementing Ruby's Tap Method

Ruby's tap method can be extremely useful, and was recently listed as one of the top five Ruby methods that you should be using on an Engine Yard blog. I wanted to see if I could implement my own version of the method to get a better understanding of how it works.

In Ruby On Rails By Leigh Halliday January 24, 2015

Leigh Halliday

Copying Postgres Table with its Attributes

When we first modelled the data it made sense, but over time business requirements change and we discovered that the model made more sense to be split in half to satisfy 2 unique models instead of 1. This article is about creating a copy of the table, while preserving it's column settings and characteristics (default value, not null, etc...)

In Databases By Leigh Halliday January 23, 2015

Leigh Halliday

Working with Enumerables: Four powerful collection methods

Mastering the Enumerable module can help you improve your Ruby skills drastically. It's a very powerful module and something you'll end up using more and more as you get comfortable with it. Here are 4 methods you can run on collections to help you transform and filter them.

In Ruby On Rails By Leigh Halliday January 22, 2015

Leigh Halliday

Adding translations to your Rails website

In this article I will explore the steps and code necessary to add I18n (internationalization: localization and translation) to this website. Topics included involve routing, static content, and dynamic content.

In Ruby On Rails By Leigh Halliday January 17, 2015

Leigh Halliday