miguelbermudez

This TRIGGER function calls PosgreSQL's NOTIFY command with a JSON payload. You can listen for these calls and then send the JSON payload to a message queue (like AMQP/RabbitMQ) or trigger other actions.

Create the trigger with notify_trigger.sql.

When declaring the trigger, supply the column names you want the JSON payload to contain as arguments to the function (see create_triggers.sql)

The payload returns a JSON object:

miguelbermudez

{:aliases
 {:dev {:extra-deps {com.bhauman/rebel-readline {:mvn/version "0.1.2"}
                     org.clojure/tools.nrepl {:mvn/version "0.2.12"}
                     cider/cider-nrepl {:mvn/version "0.17.0-SNAPSHOT"}}
        :main-opts ["-m" "repl"]}}}

miguelbermudez

(ns reduxish.state-tools
  (:require-macros [cljs.core.async.macros :refer [go go-loop]])
  (:require [cljs.core.async.impl.protocols :refer [WritePort ReadPort]]
            [cljs.core.async :refer [<!]]))

(defn channel?
  "A predicate that determines if the provided thing is a core.async channel"
  [ch]
  (and (satisfies? WritePort ch) (satisfies? ReadPort ch)))

miguelbermudez

Clojure Destructuring Tutorial and Cheat Sheet

(Related blog post)

Simply put, destructuring in Clojure is a way extract values from a datastructure and bind them to symbols, without having to explicitly traverse the datstructure. It allows for elegant and concise Clojure code.

Vectors

miguelbermudez

Windows 10 Development Environment for Scala

This is a guide for Scala and Java development on Windows, using Windows Subsystem for Linux, although a bunch of it is applicable to a VirtualBox / Vagrant / Docker subsystem environment. This is not complete, but is intended to be as step by step as possible.

Sadly, much of this pertains to Git, GPG, SSH, and Windows all not working, rather than Windows Subsystem for Linux. There is no unified command line experience for native Windows still -- instead, there's a bunch of different conflicting programs which all bring along their own environment and need to be told about each other.

Harden Windows 10

Read the entire Decent Security guide, and follow the instructions, especially:

miguelbermudez

CLJ_NREPL_PORT:=22340
FIGWHEEL_PORT:=22345

CLJS_JAR_VERSION:=1.7.48
CLJS_JAR_URL:=https://github.com/clojure/clojurescript/releases/download/r$(CLJS_JAR_VERSION)/cljs.jar

.PHONY: def_target

def_target : null

miguelbermudez

Checking the State of Your States

If applicable, make sure your design component accounts for all these states. This is basically copied from the Nine States of Design Medium article. 😛

• Initial state: What happens before your component does anything? Maybe it’s the first time a user sees it. Maybe it’s not activated yet. Essentially, the component exists but hasn’t started.
• Loading state: Have you accounted for when a user will be waiting for something to happen? What does that look like?
• Empty state: Your component has initialized, but it’s empty. No data. No Items. Now may be a good time to get the user to act (“Do this thing!”), or to reward them (“Good job, everything is taken care of”).
• One state: You have some data. On an input, this may be after the first keystroke. In a list, it might be when you have one item (or one left).
• Some data state: This is usually what you think

miguelbermudez

// getComponent is a function that returns a promise for a component
// It will not be called until the first mount
function asyncComponent(getComponent) {
  return class AsyncComponent extends React.Component {
    static Component = null;
    state = { Component: AsyncComponent.Component };

    componentWillMount() {
      if (!this.state.Component) {
        getComponent().then(Component => {

miguelbermudez

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

miguelbermudez

Atom Clojure Setup

This describes how I setup Atom for an ideal Clojure development workflow. This fixes indentation on newlines, handles parentheses, etc. The keybinding settings for enter (in keymap.cson) are important to get proper newlines with indentation at the right level. There are other helpers in init.coffee and keymap.cson that are useful for cutting, copying, pasting, deleting, and indenting Lisp expressions.

Install Atom

Download Atom

The Atom documentation is excellent. It's highly worth reading the flight manual.