Sergey Zenchenko sergeyzenchenko

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).

Essential JavaScript Links

I no longer mantain this list. There are lots of other very comprehensive JavaScript link lists out there. Please see those, instead (Google "awesome JavaScript" for a start).

Focus

A Focus is a way to work with particular parts of a large chunk of data. On the most basic level, it lets you get and set fields of a record in a simple and composable way. This means you could avoid writing special record update syntax and use something that composes much more elegantly.

This API is inspired by the concept of Bidirectional Lenses as described by Nate Foster and seen in a modified form in Haskell as "lenses" and in ClojureScript as "cursors". My personal opinions and understanding comes from this talk by Simon Peyton Jones, discussions with @seliopou, and a basic understanding of Nate Foster's PhD thesis on bidirectional lenses. I chose the name "Focus" for this outline because it is sort of like a lens that only lets you see in one direction.

Here's the pseudocode that describes the basic API:

modul

UIKonf 2014 Slides

Christopher Downer: Designing Custom Interfaces, slides missing
Katrin Apel: Mobile Backends as a Service - Ready for Production?, slides
Max Seelemann: TextKit For The Rest Of Us, slides
David Rönnqvist: OpenGL (ES) demystified, slides missing
Nick Lockwood: Image Performance, slides
Eric Allam: Beyond the Basics - Building Better Transitions on iOS 7, slides
Sally Shepard: accessibility & voice over, slides missing
[Rachel Andrew](https://twitter.com/rachelandrew

	@implementation CKComponent (Injection)

	- (void)updateOnClassInjection {
	dispatch_async(dispatch_get_main_queue(), ^{

	// Search for the first component hostig view
	id comp = self;
	while (comp) {
	comp = [comp nextResponder];
	if ([comp isKindOfClass:[CKComponentHostingView class]]) {

	/*
	* This is an example provided by Facebook are for non-commercial testing and
	* evaluation purposes only.
	*
	* Facebook reserves all rights not expressly granted.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL
	* FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN

	#include <unistd.h>
	#include <mach/mach.h>
	#include <mach/mach_vm.h>
	#include <mach-o/dyld.h>

	int
	main (int argc, char * argv[])
	{
	volatile char * library;
	const mach_vm_size_t page_size = getpagesize ();

	import { Component } from "React";

	export var Enhance = ComposedComponent => class extends Component {
	constructor() {
	this.state = { data: null };
	}
	componentDidMount() {
	this.setState({ data: 'Hello' });
	}
	render() {

	function fswatch_propagate_pwd_changes_to_docker () {
	echo "Starting fswatch on $PWD"
	# tracking previous not to get into endless loop of changing the same file
	local previous=''
	fswatch -r "$PWD" \| while read file; do
	if [[ previous != "$file" ]]; then
	docker run --rm -v "$PWD":"$PWD" busybox touch -c "$file"
	fi
	previous="$file"
	done

	protocol ISubscriber {
	typealias Element

	func disposable() -> RACCompoundDisposable

	func sendNext(e: Element)
	func sendError(e: NSError)
	func sendCompleted()
	}