jakub-g

navigator.sendBeacon(url, data)

The data parameter is an ArrayBufferView, Blob, DOMString, or FormData object containing the data to be transmitted.

• no plain old key-value JS object :| serialization of an object to a string up to the developer

• always POST, not possible to send GET :|

• when DOMString passed, the request type is Content-Type: text/plain, hence expressjs middlewares that read postdata won't process it :/ need to write custom middleware

jakub-g

1. Grab old version of Firefox from Mozilla's FTP. They downloads are placed in folders that follow a simple naming convention. For example v63.0 is here:

https://ftp.mozilla.org/pub/firefox/releases/63.0/win64/en-US/

2. Run the installer and install it to a folder like c:\software\firefox63

3. IMPORTANT: turn off internet connectivity at system level before running Firefox for the first time! Otherwise it will automatically self-update! (Windows 10 has "airplane mode").

4. Create a shortcut with special command line switches

jakub-g

open .vscode/settings.json

files.exclude
files.watcherExclude
search.exclude

https://code.visualstudio.com/docs/getstarted/settings

jakub-g

• Using the American date format https://twitter.com/csswizardry/status/1103677023191515137

• Using Fahrenheit in CMT

jakub-g

When sharing your screen -- during an on-site presentation, a remote meeting presentation, a conference talk -- there are a lot of small things to consider to make the experience better for the viewers. It's paramount to accommodate for the fact that your viewers will perceive things differently from youself due to where they are and their individual predispositions.

General

• Make sure your pointer is visible to the users (or accommodate for it if impossible).

  • For example, when sharing mobile screens, people don't see where your finger is. Demos which rely on you tapping the device in places invisible to the observers are bad. Accommodate for that by telling upfront where are you going to tap.
  • When using tools like Vysor, prefer clicking things on your laptop with your mouse, instead of directly tapping with your finger on the device.

• Make sure people in the room and the ones connected remotely *c

jakub-g

ConEmu theme: Solarized Light + 8. = #dddddd

cat ~/.gitconfig

[color "diff"]
        new = bold black bold green
        old = bold black bold red

jakub-g

Rationale for serving ES6

• Write ES6 without transpilation (perf reasons aside; developer convenience)
• Perf reasons (untranspiled code is smaller and faster)

Expectations vs reality

┓┏┓┏┓┃
┛┗┛┗┛┃＼○／

jakub-g

A collection of web performance facts

Inspired by: https://wpostats.com/

Mobile vs WiFi

• 2018.11 OpenSignal study:
  • mobile vs wifi:
    • In 33 countries, or 41% of those analyzed by OpenSignal, mobile delivers a faster download experience than Wifi
  • 4G vs wifi:

jakub-g

• Check that you're debugging the proper file (correct URL, correct folder etc.)

• Nuclear option: remove everything

• Check the errors

• Compare behavior before and after

• Compare logs before and after

• Check the commits in the meantime

• "Nothing happens, and no errors": Look for missing callbacks

jakub-g

Network time vs JS eval time vs JS at runtime

• Network time: DNS, TCP, TLS, data transfer

• High Performance Browser Networking

  • https://hpbn.co/

• "Network protocols for anyone who knows a programming language, 20 minute read"

  • https://www.destroyallsoftware.com/compendium/network-protocols?share_key=97d3ba4c24d21147