Andy Kish Kobold

PostgreSQL is Enough

Background and Cron Jobs

Tether Drop + React Portal + Redux

This is an example of using Tether Drop with React Portal (and Redux for managing the state). I was asked if using React Portal is redundant, as both libraries pull the content into the <body>. Using only Drop would cause an invariant violation in React becuase of the DOM mutation, so I'm using React Portal to first bring it outside without React complaining (I don't know how React Portal does it, I haven't checked out the source, but it works). Once it's out of React's supervision, I can apply Drop to it.

Dropdown.jsx is the actual dropdown component
App.jsx is just an demo that uses it

This is my lazy way out of this limitation using an existing library that has much more features than you need, but chances are that you're going to need a library like React Portal anyway for stuff like modals.

Notes

Adventures in Python Core Dumping

After watching Bryan Cantrill's presentation on [Running Aground: Debugging Docker in Production][aground] I got all excited (and strangely nostalgic) about the possibility of core-dumping server-side Python apps whenever they go awry. This would theoretically allow me to fully inspect the state of the program at the point it exploded, rather than relying solely on the information of a stack trace.

Hello software developers,

Please check your code to ensure you're not making one of the following mistakes related to cryptography.

I. General Mistakes

Writing your own home-grown cryptography primitives (For example: Mifare Classic)
- Exception: For the sake of learning, but don't deploy it in production.
Using a fast hash function (e.g. MD5, SHA256) for storing passwords. Use bcrypt instead.
Not using a cryptographically secure random number generator

Tether is a great library for positioning stuff (tooltips, modals, hints, etc) in your web app.

But, as I use React, it was pretty problematic for me, as Tether mutates the DOM and React breaks miserably when it sees mutated DOM. The solution is to have the tethered element outside the part of the DOM tree which is controlled by React (in this case, I use document.body).

That's why I created 2 helpers to use Tether with React.

The first one, TetheredElement is a plain JS helper to create a new element, attach it to some other one via Tether, and populate it with some React component.

The second one, TetherTarget is a React component and it uses TetheredElement to integrate it further with React, so that you can attach components to each other with Tether, without leaving the cozy React/JSX world and worrying about manual DOM operations. Just write:

	#!/usr/bin/env python
	"""
	The Needleman-Wunsch Algorithm
	==============================

	This is a dynamic programming algorithm for finding the optimal alignment of
	two strings.

	Example
	-------

	-- Create a group
	CREATE ROLE readaccess;

	-- Grant access to existing tables
	GRANT USAGE ON SCHEMA public TO readaccess;
	GRANT SELECT ON ALL TABLES IN SCHEMA public TO readaccess;

	-- Grant access to future tables
	ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO readaccess;

	const Status = {
	REQUEST: 'requrest',
	SUCCESS: 'success',
	FAILURE: 'failure'
	};

	function requestAction (payload, type) {
	return {
	...payload,
	status: Status.REQUEST,

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<!-- The above 3 meta tags must come first in the head; any other head content must come after these tags -->
	<title>Websocket Scale</title>

	<style>

	#! /fi/cl/9.0/bin/linuxamd64.64/mlisp -#D

	(in-package :user)

	(defparameter instance-exceptions
	;; these instances are known to be running and are exceptions:
	...)

	(defparameter volume-exceptions
	;; these instances are known to be running and are exceptions: