slikts

Why using the children prop makes React.memo() not work

I've recently ran into a pitfall of [React.memo()][memo] that seems generally overlooked; skimming over the top results in Google just finds it mentioned in passing in a [React issue][regit], but not in the [FAQ] or API [overview][react-api], and not in the articles that set out to explain React.memo() (at least the ones I looked at). The issue is specifically that nesting children defeats memoization, unless the children are just plain text. To give a simplified code example:

const Memoized = React.memo(({ children }) => (<div>{children}</div>));
// Won't ever re-render
<Memoized>bar</Memoized>
// Will re-render every time; the memoization does nothing

jonashaag

from django.core.mail.message import make_msgid


class FastMailBackendMixin:
    """Work around slow development email backend due to slow socket.getfqdn() call.

    This simply uses "example.com" instead of your local machine's hostname.
    """
    def send_messages(self, messages):
        for message in messages:

chourobin

Bridging Native & React for iOS & Android

js -> native

• Simple Example
• Callbacks
• Promises
• Properties

native -> js

MichaelDanielTom

/**
 * HighlightableImage.js
 *
 * If we simply change the source prop of an Image in the render method, the
 * image blinks, and there is no image for a fraction of a second. This is
 * solved by mounting 2 images and changing their opacity.
 *
 */
import React from 'react'
import {

cliffano

# This gist is compatible with Ansible 1.x .
# For Ansible 2.x , please check out:
# - https://gist.github.com/dmsimard/cd706de198c85a8255f6
# - https://github.com/n0ts/ansible-human_log

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#

steipete

// Taken from the commercial iOS PDF framework http://pspdfkit.com.
// Copyright (c) 2014 Peter Steinberger, PSPDFKit GmbH. All rights reserved.
// Licensed under MIT (http://opensource.org/licenses/MIT)
//
// You should only use this in debug builds. It doesn't use private API, but I wouldn't ship it.

// PLEASE DUPE rdar://27192338 (https://openradar.appspot.com/27192338) if you would like to see this in UIKit.

#import <objc/runtime.h>
#import <objc/message.h>