[WIP] Major refactor and API change for version 2.0

This commit is contained in:
Talia 2024-01-17 14:54:53 +01:00
parent c5c4e973a5
commit 7a789d407e
2 changed files with 133 additions and 112 deletions

View File

@ -53,9 +53,8 @@ const getCustom = args => args.reduce(
const isElement = object => HTMLElement.prototype.isPrototypeOf(object)
const isReactive = object => object
&& (typeof object == "object")
&& ("addEventListener" in object)
&& ("value" in object)
&& (object instanceof EventTarget)
&& ("subscribe" in object)
const toChild = arg => {
if (typeof arg == "string" || typeof arg == "number") {

240
state.js
View File

@ -5,82 +5,56 @@ const kebabToCamel = string => string.replace(/([a-z])-([a-z])/g, (_, a, b) => a
export class ChangeEvent extends Event {
#final
#values
constructor(...changes) {
super('change')
this.changes = changes
}
get values() {
if (!this.#values) {
const values = new Map()
for (const {property, from, to} of this.changes) {
let list = values.get(property)
if (!list) {
list = [from]
values.set(property, list)
}
list.push(to)
}
this.#values = values
}
return this.#values
}
get final() {
if (!this.#final) {
this.#final = new Map(this.changes)
this.#final = new Map()
for (const [property, list] of this.values) {
if (list[0] !== list[list.length-1]) {
this.#final.set(property, list[list.length-1])
}
}
}
return this.#final
}
}
export class SimpleState extends EventTarget {}
export class MapStorage extends Storage {
#map = new Map()
key(index) {
return [...this.#map.keys()][index]
}
getItem(keyName) {
if (this.#map.has(keyName))
return this.#map.get(keyName)
else
return null
}
setItem(keyName, keyValue) {
this.#map.set(keyName, String(keyValue))
}
removeItem(keyName) {
this.#map.delete(keyName)
}
clear() {
this.#map.clear()
}
}
export class State extends SimpleState {
#target
#options
export class SimpleState extends EventTarget {
#synchronous
#queue
#forwardCache
#abortController
#nested = new Map()
#weakRef = new WeakRef(this)
#abortController = new AbortController
static isState(object) { return SimpleState.prototype.isPrototypeOf(object) }
constructor(target={}, options={}) {
constructor({synchronous, methods}={}) {
super()
this.#abortController = new AbortController
this.#synchronous = !!synchronous
abortRegistry.register(this, this.#abortController)
this.#options = options
this.#target = target
this.values = new Proxy(target, {
set: (_target, prop, value) => {
const old = this.get(prop)
if (old !== value) {
this.emit(prop, value)
if (this.#options.shallow) {
if (State.isState(old)) this.disown(prop, old)
if (State.isState(value)) this.adopt(prop, value)
}
this.set(prop, value)
}
return true
},
get: (_target, prop) => this.get(prop),
})
this.addEventListener
// Try running a "<name>Changed" method for every changed property
// Can be disabled to maybe squeeze out some performance
if (options.methods ?? true) {
if (methods ?? true) {
this.addEventListener("change", ({final}) => {
final.forEach((value, prop) => {
if (`${prop}Changed` in this) this[`${prop}Changed`](value)
@ -89,9 +63,32 @@ export class State extends SimpleState {
}
}
// When you only need one value, you can skip the proxy.
set value(value) { this.values.value = value }
get value() { return this.values.value }
subscribe(prop, callback) {
if (!callback) return this.subscribe("value", prop)
const controller = new AbortController()
this.addEventListener("change", ({final}) => {
if (final.has(prop)) return callback(final.get(prop))
}, {signal: controller.signal})
callback(this.value)
return () => controller.abort()
}
emit(property, from, to, options={}) {
const change = {property, from, to, ...options}
if (!this.synchronous) {
if (!this.#queue) {
this.#queue = []
queueMicrotask(() => {
this.dispatchEvent(new ChangeEvent(...this.#queue))
this.#queue = undefined
})
}
this.#queue.push(change)
} else {
this.dispatchEvent(new ChangeEvent([change]))
}
}
adopt(prop, state) {
let handlers = this.#nested.get(state)
@ -101,11 +98,12 @@ export class State extends SimpleState {
this.#nested.set(state, handlers)
}
const ref = this.#weakRef
const handler = () => ref.deref()?.emit(prop, state)
const handler = () => ref.deref()?.emit(prop, state, state, {state: true})
handlers.set(prop, handler)
state.addEventListener("change", handler, {signal: this.#abortController.signal})
state.addEventListener("change", handler, {signal: this.ignal})
}
disown(prop, state) {
const handlers = this.#nested.get(state)
const handler = handlers.get(prop)
@ -116,29 +114,49 @@ export class State extends SimpleState {
}
}
// Anounces that a prop has changed
emit(prop, value) {
if (this.#options.defer ?? true) {
if (!this.#queue) {
this.#queue = []
queueMicrotask(() => {
this.dispatchEvent(new ChangeEvent(...this.#queue))
this.#queue = undefined
})
}
this.#queue.push([prop, value])
} else {
this.dispatchEvent(new ChangeEvent([prop, value]))
}
get signal() { return this.#abortController.signal }
get synchronous() { return this.#synchronous }
}
export class State extends SimpleState {
#target
#shallow
#forwardCache
static isState(object) { return SimpleState.prototype.isPrototypeOf(object) }
constructor(target={}, {shallow, ...options}={}) {
super(options)
this.#shallow = !!shallow
this.#target = target
this.values = new Proxy(target, {
set: (_target, prop, value) => {
const old = this.get(prop)
if (old !== value) {
this.emit(prop, old, value)
if (this.#shallow) {
if (State.isState(old)) this.disown(prop, old)
if (State.isState(value)) this.adopt(prop, value)
}
this.set(prop, value)
}
return true
},
get: (_target, prop) => this.get(prop),
})
}
forward(property="value", fallback) {
set value(value) { this.values.value = value }
get value() { return this.values.value }
forward(property="value") {
if (!this.#forwardCache) this.#forwardCache = new Map()
const cached = this.#forwardCache.get(property)?.deref()
if (cached) {
return cached
} else {
const forwarded = new ForwardState(this, property, fallback)
const forwarded = new ForwardState(this, property)
const ref = new WeakRef(forwarded)
this.#forwardCache.set(property, ref)
forwardFinalizationRegistry.register(forwarded, [this.#forwardCache, property])
@ -159,20 +177,6 @@ export class State extends SimpleState {
const prop = args[0]
return this.#target[prop]
}
subscribe(prop, callback) {
if (!callback) return this.subscribe("value", prop)
const controller = new AbortController()
this.addEventListener("change", ({final}) => {
if (final.has(prop)) return callback(final.get(prop))
}, {signal: controller.signal})
callback(this.value)
return () => controller.abort()
}
// Backwards compatibility
get proxy() { return this.values }
}
const forwardFinalizationRegistry = new FinalizationRegistry(([cache, name]) => {
@ -182,21 +186,19 @@ const forwardFinalizationRegistry = new FinalizationRegistry(([cache, name]) =>
export class ForwardState extends SimpleState {
#backend
#property
#fallback
constructor(backend, property, fallback) {
constructor(backend, property) {
super()
this.#backend = backend
this.#property = property
this.#fallback = fallback
const ref = new WeakRef(this)
const abortController = new AbortController()
backend.addEventListener("change", event => {
const state = ref.deref()
if (state) {
const relevantChanges = event.changes
.filter(([name]) => name === property)
.map(([_, value]) => ["value", value])
.filter(({property: name}) => name === property)
.map(({from, to}) => ({property: "value", from, to}))
if (relevantChanges.length > 0)
state.dispatchEvent(new ChangeEvent(...relevantChanges))
} else {
@ -205,7 +207,7 @@ export class ForwardState extends SimpleState {
}, {signal: abortController.signal})
}
get value() { return this.#backend.values[this.#property] ?? this.#fallback }
get value() { return this.#backend.values[this.#property]}
set value(value) { this.#backend.values[this.#property] = value }
}
@ -280,8 +282,8 @@ export const component = (generator, name) => {
super()
this.state = new State(Object.fromEntries([...this.attributes].map(attribute => [kebabToCamel(attribute.name), attribute.value])))
this.state.addEventListener("change", event => {
for (const [name, value] of event.changes) {
const kebabName = camelToKebab(name)
for (const {property, to: value} of event.changes) {
const kebabName = camelToKebab(property)
if (this.getAttribute(kebabName) !== String(value))
this.setAttribute(kebabName, value)
}
@ -297,14 +299,12 @@ export const component = (generator, name) => {
class ComposedState extends SimpleState {
#func
#states
#options
constructor(func, options, ...states) {
super()
super(options)
this.#func = func
this.#states = states
this.#options = options
const abortController = new AbortController()
abortRegistry.register(this, abortController)
@ -322,7 +322,7 @@ class ComposedState extends SimpleState {
#microtaskQueued
scheduleUpdate() {
if (this.#options.defer) {
if (this.defer) {
if (!this.#microtaskQueued) {
queueMicrotask(() => {
this.#microtaskQueued = false
@ -336,8 +336,10 @@ class ComposedState extends SimpleState {
}
update() {
this.value = this.#func(...this.#states.map(state => state.value))
this.dispatchEvent(new ChangeEvent([["value", this.value]]))
const value = this.#func(...this.#states.map(state => state.value))
const change = {property: "value", from: this.value, to: value}
this.value = value
this.dispatchEvent(new ChangeEvent([change]))
}
}
@ -359,7 +361,6 @@ const mutationObserver = new MutationObserver(mutations => {
export class DOMState extends SimpleState {
#target
#defer
#getValue
#equal
@ -367,8 +368,7 @@ export class DOMState extends SimpleState {
#changedValue = false
constructor(target, options) {
super()
this.#defer = options.defer ?? false
super(options)
this.#target = target
this.#getValue = options.get ?? (target => target.value)
this.#equal = options.equal ?? ((a, b) => a===b)
@ -396,7 +396,7 @@ export class DOMState extends SimpleState {
this.#old = current
if (this.#defer) {
if (this.defer) {
if (!this.#changedValue) {
queueMicrotask(() => {
this.#changedValue = false
@ -410,4 +410,26 @@ export class DOMState extends SimpleState {
}
}
export class MapStorage extends Storage {
#map = new Map()
key(index) {
return [...this.#map.keys()][index]
}
getItem(keyName) {
if (this.#map.has(keyName))
return this.#map.get(keyName)
else
return null
}
setItem(keyName, keyValue) {
this.#map.set(keyName, String(keyValue))
}
removeItem(keyName) {
this.#map.delete(keyName)
}
clear() {
this.#map.clear()
}
}
export default State