Todsaporn Banjerdkit katopz

Observables

You don't really need a framework or fancy cutting-edge JavaScript features to do two-way data binding. Let's start basic - first and foremost, you need a way to tell when data changes. Traditionally, this is done via an Observer pattern, but a full-blown implementation of that is a little clunky for nice, lightweight JavaScript. So, if native getters/setters are out, the only mechanism we have are accessors:

var n = 5;
function getN() { return n; }
function setN(newN) { n = newN; }

console.log(getN()); // 5

setN(10);

React Native Trouble

Updating to macOS Sierra is causing trouble with React Native due to some of the Node.js and system utilities it uses. Specifically the watch utility fails due to a limit on the number of files which can be opened at a time.

The following command shows the current limit.

launchctl limit maxfiles

Learn Go in ~5mins

This is inspired by A half-hour to learn Rust and Zig in 30 minutes.

Basics

Your first Go program as a classical "Hello World" is pretty simple:

First we create a workspace for our project:

Note

This gist has graduated to a proper repo: preactjs/preact-root-fragment

`preact-root-fragment`: partial root rendering for Preact

This is a standalone Preact 10+ implementation of the deprecated replaceNode parameter from Preact 10.

It provides a way to render or hydrate a Preact tree using a subset of the children within the parent element passed to render():

	# create an account, create an app
	# @see https://apps.twitter.com/

	# retrieve the access tokens
	# @see https://dev.twitter.com/oauth/reference/post/oauth2/token

	# create the file ~/twitter_api
	nano ~/twitter_api
	Authorization: OAuth oauth_consumer_key="XXXXXX", oauth_nonce="11111111", oauth_signature="XXXXXX", oauth_signature_method="HMAC-SHA1", oauth_timestamp="1450728725", oauth_token="99999-XXXXXX", oauth_version="1.0"

	var bip39 = require("bip39");
	var ethwallet = require('ethereumjs-wallet');
	var ProviderEngine = require("web3-provider-engine");
	var WalletSubprovider = require('web3-provider-engine/subproviders/wallet.js');
	var Web3Subprovider = require("web3-provider-engine/subproviders/web3.js");
	var Web3 = require("web3");

	// Insert raw hex private key here, e.g. using MyEtherWallet
	var wallet = ethwallet.fromPrivateKey(Buffer.from('abcdef', 'hex'));

	// 1. Open the browser developper console on the network tab
	// 2. Start the video
	// 3. In the dev tab, locate the load of the "master.json" file, copy its full URL
	// 4. Run: node vimeo-downloader.js "<URL>"
	// 5. Combine the m4v and m4a files with mkvmerge

	const fs = require('fs');
	const url = require('url');
	const https = require('https');

	MERGE {destination} T
	USING (
	SELECT * EXCEPT(rn)
	FROM (
	SELECT
	*,
	row_number() over (PARTITION BY {primary_keys} ORDER BY updated_at DESC) AS rn
	FROM {source})
	WHERE rn = 1
	) S

	const eventFilter = (contractAddress, contractAbi, eventName, _provider) => {
	const provider = _provider
	// this will return an array with an object for each event
	const events = contractAbi.abi.filter(obj => obj.type ? obj.type === "event" : false);
	// getting the Transfer event and pulling it out of its array
	const event = events.filter(event => event.name === eventName)[0];
	// getting the types for the event signature
	const types = event.inputs.map(input => input.type)
	// knowing which types are indexed will be useful later
	let indexedInputs = [];