Migration from jQuery

FLASH.js keeps the DX you love — $(".card").addClass("active") → F(".card").addClass("active") — but embraces the modern platform.

jQuery$ → FESM

Philosophy: No claim of 100% compatibility. FLASH.js intentionally diverges where the platform now has a better primitive (e.g., fetch over $.ajax).

Side-by-side

jQuery	FLASH.js
`$(selector)`	`F(selector)` — `Flash` is alias; `F` is primary
`$(".card").addClass("a")`	`F(".card").addClass("a")`
`$el.html()` / `text()` / `val()`	`F(el).html()` / `text()` / `val()`
`$el.attr(k,v)` / `removeAttr`	`F(el).attr(k,v)` / `removeAttr`
`$el.on("click", fn)`	`F(el).on("click", fn)`
`$(document).on("click",".btn", fn)`	`F(document).on("click",".btn", fn)`
`$el.trigger("evt")`	`F(el).trigger("evt", detail)`
`$el.animate(props, opts)` — jQuery FX	`F(el).animate(keyframes, opts)` — Web Animations API
`$.ajax({ url, method })`	`await F.http.get("/api")` / `F.http.json()` / `F.http.request()`
`localStorage` manual JSON	`F.storage.set/get/has` — JSON auto

Key differences

ESM: import { F } from "flash.js" instead of global $. UMD global still available as F/Flash for migration.
Fetch: F.http throws on non-2xx; handle via catch and error.status — no success/error callbacks.
Animation: Keyframes use Web Animations API syntax { opacity: [0,1] } or arrays; always returns Promise.
No Sizzle: selectors are native querySelectorAll — no jQuery custom pseudos.
Collection vs jQuery object: FLASH's Collection is iterable and array-like; use get(), each, map, filter.

ESM & tree-shaking

// Before
import $ from "jquery";
$(".card").addClass("active");

// After — ESM + tree-shaking
import { F } from "flash.js";
F(".card").addClass("active");

// Only what you use
import { http } from "flash.js/http";

Compatibility note

FLASH.js is not a drop-in jQuery shim. Porting is usually search-and-replace for DOM/events, but HTTP and animation need small rewrites to modern APIs. The docs' API reference is exactly the implemented surface — no hidden shims.

API Reference →