ivanberry

/* Exercise: Loops and Functions #43 */
package main

import (
	"fmt"
	"math"
)

func Sqrt(x float64) float64 {
	z := float64(2.)

ivanberry

Two way iframe communication

The main difference between the two pages is the method of sending messages. Recieving messages is the same in both.

Parent

Send messages to iframe using iframeEl.contentWindow.postMessage Recieve messages using window.addEventListener('message')

iframe

ivanberry

function translateError(msg) {
  var newErr = new Error(msg); // placed here to get correct stack
  return e => { 
    newErr.originalError = e;
    throw newErr;
  }
}

async function asyncTask() {  
    const user = await UserModel.findById(1).catch(translateError('No user found'))

ivanberry

npm set registry https://registry.npm.taobao.org # 注册模块镜像
npm set disturl https://npm.taobao.org/dist # node-gyp 编译依赖的 node 源码镜像

## 以下选择添加
npm set sass_binary_site https://npm.taobao.org/mirrors/node-sass # node-sass 二进制包镜像
npm set electron_mirror https://npm.taobao.org/mirrors/electron/ # electron 二进制包镜像
npm set puppeteer_download_host https://npm.taobao.org/mirrors # puppeteer 二进制包镜像
npm set chromedriver_cdnurl https://npm.taobao.org/mirrors/chromedriver # chromedriver 二进制包镜像
npm set operadriver_cdnurl https://npm.taobao.org/mirrors/operadriver # operadriver 二进制包镜像
npm set phantomjs_cdnurl https://npm.taobao.org/mirrors/phantomjs # phantomjs 二进制包镜像

ivanberry

Install MongoDB with Homebrew

brew install mongodb
mkdir -p /data/db

Set permissions for the data directory

Ensure that user account running mongod has correct permissions for the directory:

ivanberry

Understanding closures, callbacks and promises

For a code newbie like myself, callbacks, closures and promises are scary JavaScript concepts.

10 months into my full-time dev career, and I would struggle to explain these words to a peer.

So I decided it was time to face my fears, and try to get my head around each concept.

Here are the notes from my initial reading. I'll continue to refine them as my understanding improves.

ivanberry

// connect() is a function that injects Redux-related props into your component.
// You can inject data and callbacks that change that data by dispatching actions.
function connect(mapStateToProps, mapDispatchToProps) {
  // It lets us inject component as the last step so people can use it as a decorator.
  // Generally you don't need to worry about it.
  return function (WrappedComponent) {
    // It returns a component
    return class extends React.Component {
      render() {
        return (

ivanberry

100 Stupid Questions for React Native

What is React Native? Is it same as React?

React Native lets you build mobile apps using only JavaScript. It uses the same design as React, letting you compose a rich mobile UI from declarative components.

https://facebook.github.io/react-native/

Is React Native easy to learn?

It depends on what project you are going to build. As for front-end developer, you nearly need to learn nothing, only a new way to write javascript (Redux, JSX).

Do I must learn Redux?

ivanberry

function interval(duration, fn){
  this.baseline = undefined
  
  this.run = function(){
    if(this.baseline === undefined){
      this.baseline = new Date().getTime()
    }
    fn()
    var end = new Date().getTime()
    this.baseline += duration

ivanberry

`emacs --daemon` to run in the background.
`emacsclient.emacs24 <filename/dirname>` to open in terminal

NOTE: "M-m and SPC can be used interchangeably".

* Undo - `C-/`
* Redo - `C-?`
* Change case: 1. Camel Case : `M-c`
               2. Upper Case : `M-u`
               3. Lower Case : `M-l`