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@jamesknelson
jamesknelson / createSubscribe.js
Created Oct 22, 2019
Turn an async function into something you can subscribe to (untested)
View createSubscribe.js
const requests = {}
export const createSubscribe = (asyncFn) => {
return subscribeToData = (params, onUpdate) => {
onUpdate('pending')
const key = JSON.stringify(params)
const request = requests[key]
if (!request) {
request = requests[key] = {
@jamesknelson
jamesknelson / README.md
Last active Oct 3, 2019
Convert a video into a gif
View README.md

A 4-line shell script to convert your movies into gifs. Defaults to 10fps, 700px wide.

WIDTH=420 FPS=12 togif input.mov

You'll need to have ffmpeg installed -- on mac, you can do this with brew:

brew install ffmpeg
@jamesknelson
jamesknelson / BlackTriangle.js
Last active Apr 8, 2019
A black triangle. It spins if ES6 works, otherwise it doesn't.
View BlackTriangle.js
export default class BlackTriangle {
constructor(selector) {
this.angle = 0;
this.innerEl = document.querySelector(selector).querySelector('.BlackTriangle-inner');
}
rotate(amount) {
this.angle = (this.angle + amount) % 360;
}
View concatStringsAndStreams.js
const CombinedStream = require('combined-stream2');
function concatStringsAndStreams(strings, ...args) {
let combinedStream = CombinedStream.create()
combinedStream.append(Buffer.from(strings[0], 'utf8'))
for (let i = 0; i < args.length; i++) {
let arg = args[i]
let string = strings[i+1]
if (arg && arg.pipe) {
combinedStream.append(arg)
View mapObservableToChunkIterator.md

mapObservableToChunkIterator(observable, mapValueToChunks, mapErrorToChunks?): Generator<Promise | Chunk[]>

A function that accepts an Observable with a subscribe() method, and optionally with a getCurrentValue() or getCurrentResult() method.

It returns a Generator that yields Promise (when waiting for a new value) or Chunk objects (i.e. objects that extend { type: string }).

By default, mapErrorToChunks takes the error emitted by an observable, and yields [{ type: 'error', error: error }].

When the observable is complete, the Generator's next() function will return { done: true }.

@jamesknelson
jamesknelson / component-routing.js
Last active Mar 19, 2019
Two APIs for routing with React that support POST methods and SSR.
View component-routing.js
/**
UPDATE:
This component and hook based routing/fetching API won't work, as `useAsync()`
is an impossible component.
In order to use async functions to respond to route changes, the functions will
need to be registered with a parent cache/provider with a unique key. As such, a
more natural component-based architecture would involve a `<Route path>` component
View UpdatePasswordForm.jsx
import { map, redirect, route } from 'navi'
function UpdatePasswordForm({ submitErrors }) {
return (
<Form
method='post'
submitErrors={submitErrors}
validate={value =>
value.password !== value.passwordConfirmation &&
{
View gist:432f00af5522ea07cbb39990a8105e0c
A React app can be split into a number of different types of functions and components, where *each type can depend only on the types above it in the hierarchy*.
This makes gives you a way to split up components and functions over your filesystem. It also helps you to keep components from growing too large, and encourages practices that make testing easier.
```
types (TypeScript typings)
^
utils (plain javascript functions)
^
contexts (React context, and provider components)
@jamesknelson
jamesknelson / create-cruv-app.sh
Last active Aug 22, 2018
React CRUV - 4 directories to solve project structure for good
View create-cruv-app.sh
create-react-app myapp
cd myapp/src
mkdir containers routes utils views
touch config.js contexts.js
mv App.* routes
sed -i '' -e 's/.\/App/.\/routes\/App/g' index.js
View HTTPOperation.ts
import * as Govern from 'govern'
import axios, { AxiosInstance, AxiosResponse, AxiosRequestConfig } from 'axios'
export interface HTTPOperation<Success = any, Rejection = any> {
hasEnded: boolean
isBusy: boolean
wasCancelled: boolean
wasSuccessful: boolean
wasRejected: boolean
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