danielnegri

My issues with Modules

In researching topics for RailsCasts I often read code in Rails and other gems. This is a great exercise to do. Not only will you pick up some coding tips, but it can help you better understand what makes code readable.

A common practice to organize code in gems is to divide it into modules. When this is done extensively I find it becomes very difficult to read. Before I explain further, a quick detour on instance_eval.

You can find instance_eval used in many DSLs: from routes to state machines. Here's an example from Thinking Sphinx.

class Article < ActiveRecord::Base

danielnegri

require 'rubygems'
require 'bundler'

Bundler.require
require './application'

namespace :assets do
  desc 'compile assets'
  task :compile => [:compile_js, :compile_css] do
  end

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Services.factory("LawnchairFactory", function($window, $log, $parse) {
  return function(name, config) {
    var collection = {};
    var array = [];
    var isArray = config && config.isArray;
    var idGetter = $parse((config && config.entryKey) ? config.entryKey : "id");
    var transformSave = (config && config.transformSave) ? config.transformSave : angular.identity;
    var transformLoad = (config && config.transformLoad) ? config.transformLoad : angular.identity;

    function getEntryId(entry){

danielnegri

Environment variables in Jekyll templates

This is one way to pass some data (API tokens, etc.) to your Jekyll templates without putting it in your _config.yml file (which is likely to be committed in your GitHub repository).

Copy the environment_variables.rb plugin to your _plugins folder, and add any environment variable you wish to have available on the site.config object.

In a Liquid template, that information will be available through the site object. For example, _layouts/default.html could contain:

danielnegri

package com.scalapenos.spray

import spray.json._

/**
 * A custom version of the Spray DefaultJsonProtocol with a modified field naming strategy
 */
trait SnakifiedSprayJsonSupport extends DefaultJsonProtocol {
  import reflect._

danielnegri

#!/bin/sh
#
# Amazon EC2 user-data file for automatic configuration of IPsec/L2TP VPN
# on a Ubuntu server instance. Tested with 14.04 (Trusty) AND 12.04 (Precise).
# With minor modifications, this script *can also be used* on dedicated servers
# or any KVM- or XEN-based Virtual Private Server (VPS) from other providers.
#
# DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC! THIS IS MEANT TO BE RUN WHEN 
# YOUR AMAZON EC2 INSTANCE STARTS!
#

danielnegri

import sbt._
import sbt.Keys._
import play.Project._
import sbtbuildinfo.Plugin._
import com.gu.SbtJasminePlugin._

object ApplicationBuild extends Build {

  val appName         = "your-app-name"
  val appVersion      = "1.0-SNAPSHOT"

danielnegri

$ ./bin/spark-shell
14/04/18 15:23:49 INFO spark.HttpServer: Starting HTTP Server
14/04/18 15:23:49 INFO server.Server: jetty-7.x.y-SNAPSHOT
14/04/18 15:23:49 INFO server.AbstractConnector: Started SocketConnector@0.0.0.0:49861
Welcome to
      ____              __
     / __/__  ___ _____/ /__
    _\ \/ _ \/ _ `/ __/  '_/
   /___/ .__/\_,_/_/ /_/\_\   version 0.9.1
      /_/

danielnegri

import scala.concurrent.Await
import scala.concurrent.ExecutionContext
import scala.concurrent.Future
import scala.concurrent.blocking
import scala.concurrent.duration.Deadline
import scala.concurrent.duration.Duration
import scala.concurrent.duration.DurationInt
import scala.concurrent.duration.DurationLong
import scala.concurrent.future
import scala.concurrent.promise

danielnegri

#!/bin/bash
#
# Bash script to setup headless Selenium (uses Xvfb and Chrome)
# (Tested on Ubuntu 12.04) trying on ubuntu server 14.04

# Add Google Chrome's repo to sources.list
echo "deb http://dl.google.com/linux/chrome/deb/ stable main" | sudo tee -a /etc/apt/sources.list

# Install Google's public key used for signing packages (e.g. Chrome)
# (Source: http://www.google.com/linuxrepositories/)