Pelle Wessman voxpelli

2015-01-29 Unofficial Relay FAQ

Compilation of questions and answers about Relay from React.js Conf.

Disclaimer: I work on Relay at Facebook. Relay is a complex system on which we're iterating aggressively. I'll do my best here to provide accurate, useful answers, but the details are subject to change. I may also be wrong. Feedback and additional questions are welcome.

What is Relay?

Relay is a new framework from Facebook that provides data-fetching functionality for React applications. It was announced at React.js Conf (January 2015).

In the .git/config file add the fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to the remote you want to fetch references to PR:s from.

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

Around 2006-2007, it was a bit of a fashion to hook lava lamps up to the build server. Normally, the green lava lamp would be on, but if the build failed, it would turn off and the red lava lamp would turn on.

By coincidence, I've actually met, about that time, (probably) the first person to hook up a lava lamp to a build server. It was Alberto Savoia, who'd founded a testing tools company (that did some very interesting things around generative testing that have basically never been noticed). Alberto had noticed that people did not react with any urgency when the build broke. They'd check in broken code and go off to something else, only reacting to the breakage they'd caused when some other programmer pulled the change and had problems.

v1.x (v1.0: Chromium 18, v1.5 & v1.6: Chromium 28)

Originally based on the stock Android browser (AOSP), 2012.

"It was around early 2013 when we made [the decision to move to Chromium]. We shipped our first Chromium-based browser in one of the Galaxy S4 models released later in 2013." (Source)

v1.0 preloaded in Galaxy S4
v1.5 preloaded in Galaxy Note 3

	# Set variables in .bashrc file

	# don't forget to change your path correctly!

	export GOPATH=$HOME/golang
	export GOROOT=/usr/local/opt/go/libexec
	export PATH=$PATH:$GOPATH/bin
	export PATH=$PATH:$GOROOT/bin

	/* bling.js */
	window.$ = document.querySelector.bind(document);
	window.$$ = document.querySelectorAll.bind(document);
	Node.prototype.on = window.on = function(name, fn) { this.addEventListener(name, fn); };
	NodeList.prototype.__proto__ = Array.prototype;
	NodeList.prototype.on = function(name, fn) { this.forEach((elem) => elem.on(name, fn)); };

	import org.apache.spark.ml.feature.{CountVectorizer, RegexTokenizer, StopWordsRemover}
	import org.apache.spark.mllib.clustering.{LDA, OnlineLDAOptimizer}
	import org.apache.spark.mllib.linalg.Vector

	import sqlContext.implicits._

	val numTopics: Int = 100
	val maxIterations: Int = 100
	val vocabSize: Int = 10000

	# coding: utf-8
	import sys
	import html2text
	import clipboard
	import webbrowser

	webpage = clipboard.get()

	text = sys.argv[1]

	const mochaList = require('mocha').reporters.Base.list;
	const mochaErrorLog = function (err, title) {
	mochaList([{
	err,
	fullTitle: () => title \|\| 'Untitled'
	}]);
	};