Hongbo Zhen bobzhen

Multiple MySQL Versions for Development

Options included below:

Using Docker docker-compose
Using Homebrew brew

Using Docker (recommended)

This gist was originally created for Homebrew before the rise of Docker, yet it may be best to avoid installing mysql via brew any longer. Instead consider adding a barebones docker-compose.yml for each project and run docker-compose up to start each project's mysql service.

Postgres Export and Import

Export

pg_dump -U [superuser] -Fc [dbname] > db.dump

Import

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

Using Solr search engine with Sunspot gem in Rails app

Solr search engine

http://lucene.apache.org/solr/

Sunspot

Sunspot - Sunspot is a Ruby library for interaction with the Solr search engine.

Download videos from egghead

Go to the egghead website, i.e. Building a React.js App

run

$.each($('h4 a'), function(index, video){
  console.log(video.href);
});

	class BaseUploader < CarrierWave::Uploader::Base
	attr_reader :width, :height
	before :cache, :capture_size

	...

	# for image size validation
	# fetching dimensions in uploader, validating it in model
	def capture_size(file)
	if version_name.blank? # Only do this once, to the original version

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
	<title>Fake auto play html audio in iOS Safari the right way</title>
	</head>
	<body>
	<h1>在 iOS Safari 中假装自动播放 HTML5 audio(音乐) 的正确方式</h1>
	<p>核心原理: 通过一个用户交互事件来主动 play 一下 audio</p>

	{
	"crv": "Ed25519",
	"d": "VoU6Pm8SOjz8ummuRPsvoJQOPI3cjsdMfUhf2AAEc7s",
	"kty": "OKP",
	"x": "l11mBSuP-XxI0KoSG7YEWRp4GWm7dKMOPkItJy2tlMM"
	}

	defmodule Expng do

	defstruct [:width, :height, :bit_depth, :color_type, :compression, :filter, :interlace, :chunks]

	def png_parse(<<
	0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A,
	_length :: size(32),
	"IHDR",
	width :: size(32),
	height :: size(32),

	defmodule Blog.Repo.Migrations.CreatePost do
	use Ecto.Migration

	def up do

	create table(:posts, primary_key: false) do
	add :id, :uuid, primary_key: true
	add :title, :string
	add :body, :text