jurassix

export const contains = (list = [], test) => list.indexOf(test) >= 0;

export const removeItemAt = (list = [], index = 0) =>
  [
    ...list.slice(0, index),
    ...list.slice(index + 1),
  ];

export const insertItemAt = (list = [], index = 0, item) =>
  [

idibidiart

Building a Maintainable, Agile Architecture for Realtime, Transactional Apps

A maintainable application architecture requires that the UI only contain the rendering logic and execute queries and mutations against the underlying data model on the server. A maintainable architecture must not contain any logic for composing "app state" on the client as that would necessarily embed business logic in the client. App state should be persisted to the database and the client projection of it should be composed in the mid tier, and refreshed as mutations occur on the server (and after network interruption) for a highly interactive, realtime UX.

With GraphQL we are able to define an easy-to-change application-level data schema on the server that captures the types and relationships in our data, and wiring it to data sources via resolvers that leverage our db's own query language (or data-oriented, uniform service APIs) to resolve client-specified "queries" and "mutations" against the schema.

We use GraphQL to dyn

paulirish

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

albertstill

class PostIndex extends React.Component {
  state = { loading: false };

  componentDidMount() {
    window.onscroll = () => {
      if (!this.state.loading
        && (window.innerHeight + window.scrollY)
          >= document.body.offsetHeight) {

        this.setState({loading: true}, () => {

cpojer

import {Router, Route} from 'react-router';
import BrowserHistory from 'react-router/lib/BrowserHistory';

import App from './components/App';
import Widget from './components/Widget';

// A wrapper to create a Relay container
function createRelayContainer(Component, props) {
  if (Relay.isContainer(Component)) {
    // Construct the RelayQueryConfig from the route and the router props.

chenglou

key is pretty much crucial for state perservation in React. As of React 0.13 it can't do the following things:

• Clone state

<Comp key={1} /><Comp key={1} />

• Preserve component state across different parents:

davinkevin

package lan.dk.podcastserver.utils.multipart;

import lan.dk.podcastserver.utils.MimeTypeUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

wincent

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).

paf31

This blog post series has moved here.

You might also be interested in the 2016 version.

chrisdone

Basic unit type:

λ> replTy "()"
() :: ()

Basic functions: