Dev box
I'm a 32-year-old Ruby on Rails web developer. With the help of friends and co-workers, I've been teaching myself Rails. I worked as a Rails developer for Crowd911 in Colorado. I live in Berlin.
In my developer blog I publish a stochastic array of thoughts and ideas, lessons, mistakes, questions and attempts as answers about Rails and Ruby. I am also posting Anki cards that I used to help myself study. In my view most knowledge is about practice. If you have thoughts, questions, ideas, corrections, arguments, feel free to email me at henryvw@gmail.com.


What is Native Code? How does it relate to a virtual environment?

Native Code is code that translates (compiles) directly to machine code and damit interacts directly with the computer's CPU and particular processor.

Ruby, or at least the most widely used version of Ruby, runs in a virtual environment. RVM manages different virtual environments based on different versions and runtime libraries of Ruby. Ruby has an interpreter. Ruby's main interpreter is called Matz's Ruby Interpreter (MRI) - written in C. The Ruby interpreter converts your Ruby code into byte code - which is one step before machine code

Another distinction that might be helpful to think about is non-managed versus managed code. Non-managed code is code written in C, C++, compiling directly to machine code. In this code, you must manually manage memory.

Managed code, or managed runtime environments, is code written in Ruby, Python, Java and other languages. Managed code includes elements like garbage collection, which manages memory allocation for you, and dynamic typing.

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Computing Theory, MRI, Interpreter, Native Code, Runtime Environment

The DOM has an API

The DOM (Document Object Model) has an API. 

Think about it. The DOM has a public interface for modification by JavaScript - or JavaScript libraries for DOM modification like JQuery.

Learning how to modify the DOM API - also called a Web API - via pure JavaScript is an important skill.

element = Document.getElementById('survey_form')

Document.activeElement

var string = document.URL

(returns the URL of the document object!)

element.id

element.className

DOM elements that are exposed and which you can modify include:

  • Element
  • URL
  • Window

More about the Web API / DOM API, which JavaScript and/or JQuery are able to interface with - https://developer.mozilla.org/en-US/docs/Web/API/Document_Object_Model

 

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Javascript, JQuery, DOM, API

What is JQuery?

JQuery is a Javascript library for DOM operations whose variables, by convention, are usually preceded by the $ (dollar) sign. 

JQuery used to be essential to front-end development. The JQuery plug-in for AJAX support was crucial, for example. Many developers knew JQuery so well, that they didn't even learn many elements of Javascript. They just brought in the JQuery library and used its functions instead.

Today (2015) JQuery is becoming sort of deprecated. The JQuery registry itself is now set to read-only and suggests people use NPM instead.

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Javascript, JQuery

What is Chosen ?

Screen shot 2015 07 29 at 3.27.14 pm

Chosen is a jQuery plug-in that fancifies / prettifies select-boxes.

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