Tag: #javascript

2024-04-24

Load the model, convert the input to a tensor, preprocess the tensor to match the model’s expected format, run inference with .predict(), and decode the prediction tensor. 2021-02-15

A demo of real-time microphone volume measurement using the Web Audio API’s AnalyserNode. 2021-01-18

How to create an NPM addon package from C++ code using the node-gyp tool and a binding.gyp file, with a JavaScript wrapper module for a more idiomatic API. 2020-12-07

JavaScript class syntax is just syntactic sugar over the traditional prototype-based inheritance. Deconstructing a simple class reveals the underlying constructor functions, prototype assignment, and use of super to call the superclass’s constructor. 2020-11-03

JavaScript has two different “prototype” concepts: an own property with the string key “prototype”, and a parent slot. Don’t confuse the two! 2020-11-02

foo.bar, foo.bar(), or foo.bar = baz - what do they mean? A deep dive into prototypical inheritance and getters/setters. 2020-11-01

Async iterators use the Symbol.asyncIterator method to define the iteration protocol. 2020-10-19

Babel is a JavaScript compiler that transforms JavaScript code. Here I use its API programmatically. 2020-10-16

require in Electron works like Node.js, allowing you to load modules, but each Renderer process has its own isolated module state. Relative module resolution depends on whether you use loadFile or loadURL. 2020-10-15

An Electron instance is basically a Chromium instance. It just has some Node.js integration. 2020-10-14

Node.js REPL uses the inspector module to safely evaluate expressions as you type, using V8’s evaluation with throwOnSideEffect: true to avoid executing harmful code. 2020-10-05

UMD modules are a way to write JavaScript code that can be used in any module system (e.g. CommonJS, AMD, or as a global variable). 2020-10-04

“Simplified CommonJS wrapping” feature is a hacky attempt to support synchronous require calls by using regexes. It’s gross. 2020-10-03

Publishing an npm package @jameshfisher/numsyslib with a stringifyRoman function that converts a number to a Roman numeral. 2020-10-01

NPM is Node.js’s package system, allowing installation of arbitrary stuff, not just Node.js modules. Packages are folders, tarballs, URLs, or version identifiers published to the NPM registry. 2020-09-30

ECMAScript modules and CommonJS modules in Node.js are interoperable. Node.js looks at file extensions and package.json fields to determine the module type. ECMAScript modules can only use import, while CommonJS modules can only use require. 2020-09-29

ES modules are just concatenated source files, with some error checking and variable renaming. Live bindings are an illusion - they’re just ordinary variables at the top-level scope. 2020-09-28

The require function in Node.js loads modules, either local files or external packages. I show the algorithm that searches node_modules directories and package.json files. 2020-09-27

JavaScript modules enable better dependency management and scoping. A guide for developers like me who still use <script> tags everywhere. 2020-09-25

A green screen implementation in the browser using WebGL and chroma key. Includes a live demo. 2020-08-09

Using the MediaRecorder API to record a canvas element as a WebM video file, allowing the user to download the recorded video. 2020-03-13

I write an ArrayBuffer to a canvas by interpreting the buffer as pixel data and using ImageData to provide the dimensions. 2020-03-01

Generators in JavaScript can act as both producers and consumers of data. An example Metric generator batches and sends data using the yield keyword. 2019-05-18

JavaScript’s function* defines a generator function, which can be used to generate and consume data. 2019-05-17

Symbols are a new fundamental data type in JavaScript, introduced in 2015. They are used to create unique object property keys that won’t clash with other properties. 2019-05-16

JavaScript iterators are objects that implement a specific protocol, providing a way to iterate over a sequence of values. The for...of loop is syntactic sugar for manually creating and using an iterator. 2019-05-10

Implementing a Promise API in JavaScript, including handling asynchronous callbacks, promise chaining, and automatically wrapping non-promise values. 2017-11-07

Promises in JavaScript represent future values. They provide a way to handle asynchronous operations, allowing chaining of callbacks. Promises can be fulfilled or rejected, with callbacks handling each case. 2017-11-05

Generating ECDH keys and deriving a shared AES key. 2017-11-03

Generating a key, encrypting and decrypting text, and explaining the implementation. 2017-11-02

A web page that allows you to sign a string using the HMAC algorithm with SHA-256, implemented using the Web Crypto API. 2017-10-31

The Web Cryptography API provides low-level crypto primitives in JavaScript, including hashing strings using SHA-256. 2017-10-30

Differences between the Web Push API in Google Chrome and Firefox. Firefox uses the Mozilla Push Service, enabling push notifications without Google’s GCM/FCM. 2017-10-24

A WebGL clock face with moving hands that updates every second, using a vertex shader to convert polar coordinates to 3D positions. 2017-10-07

The web Notification API allows web apps to display system-level notifications, requiring user permission. It has two key parts: requesting permission and creating notifications. 2017-09-07

A multiplayer web-based version of the cooperative game Spaceteam, using Pusher for real-time communication between players. 2017-01-30

Including setting up the RTCPeerConnection, creating a data channel, handling ICE candidates, and generating an offer to be shared with the remote peer. The signaling channel is copy-paste! 2017-01-16

2016-08-10

A JS function to decide the Halting Problem will always have a logical contradiction. 2013-12-24