Adam Aiken adamaiken89

Make /robots.txt aware of the Rails environment

You probably don't want Google crawling your development staging app. Here's how to fix that.

$ mv public/robots.txt config/robots.production.txt
$ cp config/robots.production.txt config/robots.development.txt

Now edit config/routes.rb to add a route for /robots.txt, and add the controller code.

最近在看Sinatra 1.3.5的源码。在Sinatra::Helpers模块中看到一个名为uri的方法，用来将一个相对路径转换为绝对路径。在该函数的代码中看到分别针对request.script_name和request.path_info进行了处理。但是并不清楚这两个参数的区别，于是做了一些reseach。

二者在RFC3875中有如下定义：

4.1.13. SCRIPT_NAME

The SCRIPT_NAME variable MUST be set to a URI path (not URL-encoded) which could identify the CGI script (rather than the script's output). The syntax is the same as for PATH_INFO (section 4.1.5) >

Originally published in June 2008

When hiring Ruby on Rails programmers, knowing the right questions to ask during an interview was a real challenge for me at first. In 30 minutes or less, it's difficult to get a solid read on a candidate's skill set without looking at code they've previously written. And in the corporate/enterprise world, I often don't have access to their previous work.

To ensure we hired competent ruby developers at my last job, I created a list of 15 ruby questions -- a ruby measuring stick if you will -- to select the cream of the crop that walked through our doors.

What to expect

Candidates will typically give you a range of responses based on their experience and personality. So it's up to you to decide the correctness of their answer.

Pry Cheat Sheet

Youtube Tutorial 2013

Command Line

pry -r ./config/app_init_file.rb - load your app into a pry session (look at the file loaded by config.ru)
pry -r ./config/environment.rb - load your rails into a pry session

Debugger

	# Author: Pieter Noordhuis
	# Description: Simple demo to showcase Redis PubSub with EventMachine
	# http://gist.github.com/348262

	# Incomplete evented Redis implementation specifically made for
	# the new PubSub features in Redis.

	# Modifications by Roger Jungemann

	require 'stringio'

	'''
	Python implementation of Haskell's

	sieve xs = sieve' xs Map.empty
	where
	sieve' [] table = []
	sieve' (x:xs) table =
	case Map.lookup x table of
	Nothing -> x : sieve' xs (Map.insert (x*x) [x] table)
	Just facts -> sieve' xs (foldl reinsert (Map.delete x table) facts)

	require 'RMagick'
	require 'yaml'

	class ImageDiff

	#max = 20
	MATRIX = 15

	def generate_array(image_path)
	result = []

	<!doctype html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<title>Exponential Regression Line Using numbers.js & d3.js</title>
	<script src="http://d3js.org/d3.v3.min.js"></script>
	<script src="numbers.js"></script>
	<style>
	body {font: 10px sans-serif;}

	input.editable_text_column {
	background-color: #FBFF8C;
	border: 1px none #FBFF8C;
	box-shadow: 0 2px 19px #AAAAAA;
	color: black;
	display: none;
	font-family: serif;
	font-size: 1em;
	font-style: italic;
	height: 30px;

	d3.select("#save").on("click", function(){
	var html = d3.select("svg")
	.attr("version", 1.1)
	.attr("xmlns", "http://www.w3.org/2000/svg")
	.node().parentNode.innerHTML;

	//console.log(html);
	var imgsrc = 'data:image/svg+xml;base64,'+ btoa(html);
	var img = '<img src="'+imgsrc+'">';
	d3.select("#svgdataurl").html(img);