Kirill Shevchenko kirillshevch

(This applies to Rails 7.1, Turbo 8.0 with esbuild and propshaft)

If you're getting a "TypeError: map.get is not a function" when navigating between pages:

Uncaught (in promise) TypeError: map.get is not a function
    at fetch (application-df30cd29ded7227ed5c827c81fa4fc9b51db518a.js:6485:20)
    at fetchWithTurboHeaders (application-df30cd29ded7227ed5c827c81fa4fc9b51db518a.js:1153:10)
    at FetchRequest.perform (application-df30cd29ded7227ed5c827c81fa4fc9b51db518a.js:1263:25)
fetch @ application-df30cd29ded7227ed5c827c81fa4fc9b51db518a.js:6485

Minimal MP4 Parser Example

Download MP4: https://github.com/alfg/mp4/blob/master/test/tears-of-steel.mp4?raw=true
Run

go run mp4_example.go tears-of-steel.mp4

go run mp4_example_2.go tears-of-steel.mp4

Rails 6 + ActionCable + Stimulus example for pushing updates to the view.

This example will show how to push updates to the view for a Model instance that has changed without the user having to refresh the page.

This example focuses more on getting ActionCable working with Stimulus. If you don't already have stimulus setup in your app, here's a great write up on how to set it up: https://medium.com/better-programming/how-to-add-stimulus-js-to-a-rails-6-application-4201837785f9

Example scenario

You have a Scan model with attributes.
You have a ScanController#show action.
A user is viewing a Scan through the show.html.slim|haml|erb view template.

Run rails new --help to see all of the options you can use to create a new Rails application:

Output for Rails 7+

Usage:
  rails new APP_PATH [options]

Options:
      [--skip-namespace], [--no-skip-namespace]              # Skip namespace (affects only isolated engines)

Source Code: https://github.com/NullVoxPopuli/rails-NPlusOneTests

Deserialization

deserialization_benchmark.rb

Each of these scenarios just changes the payload to be parsed, and does not change any deserialization options.

No Relationships

STEP 2: setup docker to run react app (dev and production) configuration: https://gist.github.com/przbadu/929fc2b0d5d4cd78a5efe76d37f891b6

Setup Docker for React development

Because we are using Docker, we are not going to install node, npm, create-react-app in our development machine, not even for generating create-react-app scaffold.

For this purpose I am using 2-step docker configuration:

In first step, we will create a simple docker container, that does only one thing, install create-react-app

How to disable page caching with create-react-app

If you currently not using a service worker resulting in old production caches being used and users not getting new versions of the app.

src/index.js

Use:

import { unregister as unregisterServiceWorker } from './registerServiceWorker'

	# https://twitter.com/josh_cheek/status/1587406334839889921
	$**?$ # => ""
	$*%$$ # => ""
	$% # => ""
	$**%$$ # => ""

	$_ = {}
	alias $*$_
	public def () = itself
	alias ** *

	require 'objspace'

	def self.show_allocations(&block)
	_ = ObjectSpace.trace_object_allocations &block
	ObjectSpace
	.each_object
	.to_a
	.filter_map do \|obj\|
	file = ObjectSpace.allocation_sourcefile obj
	line = ObjectSpace.allocation_sourceline obj

	package main

	import (
	"bytes"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	)