Amadeus Guo - juju's Blog (Page 3)

Create javascript class with prototype methods in clojurescript

When working with clojurescript, you may need to integrate with javascript codebase that asks you to provide a javascript class. Here's how to create such thing: * define a type with methods in it using deftype. (defprotocol IProvider (getData [this cbk] "Just bark") (watch [this

clojurescript

Import clojurescript into ES6 module

In case you have a clojurescript codebase and you want to use it in your ES6 project. Sadly exports-loader does not work with it out of the box. Here's what to do. Mark exported functions using ^:export metadata. ;; algo/core.cljs (defn ^:export answer

linux

Use emacs shortcut in ubuntu

Emacs shortcut is convinent for text input. (Ctrl+F forward, Ctrl+B backward, etc.) Input boxes on ubuntu does not use emacs shortcut. This command modify system defaults to use emacs keys. gsettings set org.gnome.desktop.interface gtk-key-theme "Emacs" To go back, use:

frontend

webpack secrets

Here's some tricks to use with webpack. Customize require.ensure load path By default, require.ensure load script based on the page's path. To change this path, set it with this: __webpack_public_path__ = 'static/js/' external require with __non_webpack_require__ requirejs

Change Mac GUI app environment variable

Application launched from finder on mac does not respect environment variables set by bash. Here are some methods to set environment variables for GUI applications. Simplest method: modify via bash NODEENV=development ./trader.app/Contents/MacOS/Electron Global method: launchctl setenv NODE_ENV development

react

Using a proxy for communication between two components in reactjs

This is obsolete. Use mobx or redux for complex state management. Communication between components is usually done like this. 1. Child component wants to talk to it's ancesters: In this case, pass a function or states as props down the chain. 2. Parent component

frontend

React gotcha list

React is nice. But due to its complexity, some gotcha is bound to come up in development. Here, I keep a list for future reference. * this.props.children is an array if there are multiply children, a ReactElement if there's only one children. (V0.

Go Scan, Scanf, Scanln, ReadString

In go, 4 methods are commonly used for read from stdin. Scan, Scanf, Scanln, ReadString. They are different in that: * Scan read space separated values into successive arguments. * Scanln also read space separated values into successive arguments, but terminate until a new line is

Caveats regarding react event delegation

React's mechanism of vitual DOM is well known. I recently came into two caveats that might need some attention for js developers. Event delegation React's event delegation handler is attached to the document. When it receives an event, it dispatch a synthetic event accross

linux

matplotlib install on ubuntu14

I installed matplotlib on ubuntu14 today. When I use plot.show(). It raised such error: NotImplementedError: Surface.create_for_data: Not Implemented yet. and I got a blank image. The reason is pycairo does not support python3. To fix it, sudo pip3 install cairocffi.

linux

Set proxy for terminal

For terminal export http_proxy="socks5://127.0.0.1:1080" export https_proxy="socks5://127.0.0.1:1080" What if socks proxy is not supported? Use polipo to turn a socks proxy into http proxy. Install polipo apt-get install polipo service polipo

Hugo静态网站生成

建一个网站是一件十分麻烦的事情，即使对于我们这些互联网专业人士也同样。有些时候，我们想用最快的方式建一个网站，把内容放到互联网上。 CMS系统其实就是为了达到这样的目的。那为什么不用CMS呢？使用CMS意味着你需要一台server，还要搭建DB，运行环境等，这些都要花时间。就不能更简单一些么？于是，有了静态网站生成器。它用一个最实际的特性简单，解决了一个建站的最大的实际问题：懒！使用静态网站生成器，用户一般需要把内容放在不同的文本文件里，格式常见的有markdown，resturectedText等（完全没有db）。然后，通过命令行工具生成网站所有的html文件。这些html文件放到server上即可使用，不需要复杂的后台技术。这意味着随便搞个server几乎都可以部署，发布简单，空间流量十分便宜。由于github提供了github pages静态页面服务，每个人几乎都可以免费搭建自己的站点。当然并不是所有的项目都适合静态网站生成器。静态网站生成器一般适合多读少写，以内容为主的项目。如：个人博客，github项目介绍，程序API文档等。

compile thrift on mac

The prepackaged version on thrift.apache.org contain bugs, that prevent it from being compiled on mac. To compile thrift mac, clone the version from git master branch. install boost from boost.org install various packages port install libtool port install autoconf port install

linux

use ssh as a proxy

I found out this recently. SSH can be used as a socks proxy! [http://www.catonmat.net/blog/linux-socks5-proxy/] ssh -f -N -D 0.0.0.0:1080 yourhost.com I'm using it with my webfaction account. It's nice, especially when you're in China

frontend

dojo amd config

Dojo's amd environment support baseUrl configuration, howerever, when I was trying to set it up. baseUrl does not behave correctly. Module seems to load from a directory a level up from the expected. After a while digging in dojo code, I realized this is

Feature detection in modern js

Most html5 features rely on 'xxx' in window for feature detection. There's a caveat here though, since window.xxx form won't work :: > 'ontouchstart' in window true > window.ontouchstart null

Npm behind a corporate web proxy

For npm to work behind corporate web proxy, 3 configuration command is needed. Make sure, you have them all. npm config set registry http://registry.npmjs.org/ npm config set proxy http://proxy.company.com:8080 npm config set https-proxy http://proxy.company.com:

frontend

html5 web component introduction

在软件开发中使用组件，通常能减少重复造轮子的开发，提升开发效率。使用组件的成本一般很低，无非是一个import，一个实例化。在web前端，组件却有较高的使用成本，以至于有时候会选择不用组件，而是重新发开。前端组件主要的问题包括: 1. 众多外部资源的依赖，可以有js库依赖，dom依赖，css样式依赖，图片依赖等。以bootstrap为例，要使用bootstrap的功能必须有以下几个步骤： a. 插入样式 b. 插入依赖js 2. 封装并不严格。例如，外部脚本还是可以修改组件内部结构，外部样式可以影响组件的样式。随着基于HTML5的webapp的发展，前端的组件也被提升到了新的高度。为了解决前端组件存在的诸多问题，W3C提出了web component提案，提案包括了以下四个部分：

python

pause on exception in python

Pause on exception allow you to inspect variables and stack, quite useful. The default behavior in python is to sys.exit when an exception propagate up the stack. To pause on exception, save this file as debug.py import sys def info(type, value,

python

python httplib for http debugging

In http debugging, it's useful to send a http request as exactly as you want, to pinpoint certain problem. I encountered these problems in a recent debugging session. * how can I send a http 1.0 request? * how to send a specific header? * how

frontend

Frontend local development server setup

Local http server is useful in frontend development, and there are myriad of options for its setup. From ease of setup to features, each of them has its pros and cons. python solutions twisted web twisted is a python framework for making network applications.

http

Packet truncated capture HTTP capture

Received a packet capture file with this message. The reason is ·tcpdump· by default capture packet of only 96 bytes. Larger ones are truncated. The solution is to capture with tcpdump -i eth0 -w out.pcap -s 0 -s 0 flag tell tcpdump to

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