vue3-core/packages/reactivity/src/reactive.ts

433 lines
12 KiB
TypeScript

import { def, hasOwn, isObject, toRawType } from '@vue/shared'
import {
mutableHandlers,
readonlyHandlers,
shallowReactiveHandlers,
shallowReadonlyHandlers,
} from './baseHandlers'
import {
mutableCollectionHandlers,
readonlyCollectionHandlers,
shallowCollectionHandlers,
shallowReadonlyCollectionHandlers,
} from './collectionHandlers'
import type { RawSymbol, Ref, UnwrapRefSimple } from './ref'
import { ReactiveFlags } from './constants'
import { warn } from './warning'
export interface Target {
[ReactiveFlags.SKIP]?: boolean
[ReactiveFlags.IS_REACTIVE]?: boolean
[ReactiveFlags.IS_READONLY]?: boolean
[ReactiveFlags.IS_SHALLOW]?: boolean
[ReactiveFlags.RAW]?: any
}
export const reactiveMap: WeakMap<Target, any> = new WeakMap<Target, any>()
export const shallowReactiveMap: WeakMap<Target, any> = new WeakMap<
Target,
any
>()
export const readonlyMap: WeakMap<Target, any> = new WeakMap<Target, any>()
export const shallowReadonlyMap: WeakMap<Target, any> = new WeakMap<
Target,
any
>()
enum TargetType {
INVALID = 0,
COMMON = 1,
COLLECTION = 2,
}
function targetTypeMap(rawType: string) {
switch (rawType) {
case 'Object':
case 'Array':
return TargetType.COMMON
case 'Map':
case 'Set':
case 'WeakMap':
case 'WeakSet':
return TargetType.COLLECTION
default:
return TargetType.INVALID
}
}
function getTargetType(value: Target) {
return value[ReactiveFlags.SKIP] || !Object.isExtensible(value)
? TargetType.INVALID
: targetTypeMap(toRawType(value))
}
// only unwrap nested ref
export type UnwrapNestedRefs<T> = T extends Ref ? T : UnwrapRefSimple<T>
declare const ReactiveMarkerSymbol: unique symbol
export interface ReactiveMarker {
[ReactiveMarkerSymbol]?: void
}
export type Reactive<T> = UnwrapNestedRefs<T> &
(T extends readonly any[] ? ReactiveMarker : {})
/**
* Returns a reactive proxy of the object.
*
* The reactive conversion is "deep": it affects all nested properties. A
* reactive object also deeply unwraps any properties that are refs while
* maintaining reactivity.
*
* @example
* ```js
* const obj = reactive({ count: 0 })
* ```
*
* @param target - The source object.
* @see {@link https://vuejs.org/api/reactivity-core.html#reactive}
*/
export function reactive<T extends object>(target: T): Reactive<T>
export function reactive(target: object) {
// if trying to observe a readonly proxy, return the readonly version.
if (isReadonly(target)) {
return target
}
return createReactiveObject(
target,
false,
mutableHandlers,
mutableCollectionHandlers,
reactiveMap,
)
}
export declare const ShallowReactiveMarker: unique symbol
export type ShallowReactive<T> = T & { [ShallowReactiveMarker]?: true }
/**
* Shallow version of {@link reactive()}.
*
* Unlike {@link reactive()}, there is no deep conversion: only root-level
* properties are reactive for a shallow reactive object. Property values are
* stored and exposed as-is - this also means properties with ref values will
* not be automatically unwrapped.
*
* @example
* ```js
* const state = shallowReactive({
* foo: 1,
* nested: {
* bar: 2
* }
* })
*
* // mutating state's own properties is reactive
* state.foo++
*
* // ...but does not convert nested objects
* isReactive(state.nested) // false
*
* // NOT reactive
* state.nested.bar++
* ```
*
* @param target - The source object.
* @see {@link https://vuejs.org/api/reactivity-advanced.html#shallowreactive}
*/
export function shallowReactive<T extends object>(
target: T,
): ShallowReactive<T> {
return createReactiveObject(
target,
false,
shallowReactiveHandlers,
shallowCollectionHandlers,
shallowReactiveMap,
)
}
type Primitive = string | number | boolean | bigint | symbol | undefined | null
export type Builtin = Primitive | Function | Date | Error | RegExp
export type DeepReadonly<T> = T extends Builtin
? T
: T extends Map<infer K, infer V>
? ReadonlyMap<DeepReadonly<K>, DeepReadonly<V>>
: T extends ReadonlyMap<infer K, infer V>
? ReadonlyMap<DeepReadonly<K>, DeepReadonly<V>>
: T extends WeakMap<infer K, infer V>
? WeakMap<DeepReadonly<K>, DeepReadonly<V>>
: T extends Set<infer U>
? ReadonlySet<DeepReadonly<U>>
: T extends ReadonlySet<infer U>
? ReadonlySet<DeepReadonly<U>>
: T extends WeakSet<infer U>
? WeakSet<DeepReadonly<U>>
: T extends Promise<infer U>
? Promise<DeepReadonly<U>>
: T extends Ref<infer U, unknown>
? Readonly<Ref<DeepReadonly<U>>>
: T extends {}
? { readonly [K in keyof T]: DeepReadonly<T[K]> }
: Readonly<T>
/**
* Takes an object (reactive or plain) or a ref and returns a readonly proxy to
* the original.
*
* A readonly proxy is deep: any nested property accessed will be readonly as
* well. It also has the same ref-unwrapping behavior as {@link reactive()},
* except the unwrapped values will also be made readonly.
*
* @example
* ```js
* const original = reactive({ count: 0 })
*
* const copy = readonly(original)
*
* watchEffect(() => {
* // works for reactivity tracking
* console.log(copy.count)
* })
*
* // mutating original will trigger watchers relying on the copy
* original.count++
*
* // mutating the copy will fail and result in a warning
* copy.count++ // warning!
* ```
*
* @param target - The source object.
* @see {@link https://vuejs.org/api/reactivity-core.html#readonly}
*/
export function readonly<T extends object>(
target: T,
): DeepReadonly<UnwrapNestedRefs<T>> {
return createReactiveObject(
target,
true,
readonlyHandlers,
readonlyCollectionHandlers,
readonlyMap,
)
}
/**
* Shallow version of {@link readonly()}.
*
* Unlike {@link readonly()}, there is no deep conversion: only root-level
* properties are made readonly. Property values are stored and exposed as-is -
* this also means properties with ref values will not be automatically
* unwrapped.
*
* @example
* ```js
* const state = shallowReadonly({
* foo: 1,
* nested: {
* bar: 2
* }
* })
*
* // mutating state's own properties will fail
* state.foo++
*
* // ...but works on nested objects
* isReadonly(state.nested) // false
*
* // works
* state.nested.bar++
* ```
*
* @param target - The source object.
* @see {@link https://vuejs.org/api/reactivity-advanced.html#shallowreadonly}
*/
export function shallowReadonly<T extends object>(target: T): Readonly<T> {
return createReactiveObject(
target,
true,
shallowReadonlyHandlers,
shallowReadonlyCollectionHandlers,
shallowReadonlyMap,
)
}
function createReactiveObject(
target: Target,
isReadonly: boolean,
baseHandlers: ProxyHandler<any>,
collectionHandlers: ProxyHandler<any>,
proxyMap: WeakMap<Target, any>,
) {
if (!isObject(target)) {
if (__DEV__) {
warn(
`value cannot be made ${isReadonly ? 'readonly' : 'reactive'}: ${String(
target,
)}`,
)
}
return target
}
// target is already a Proxy, return it.
// exception: calling readonly() on a reactive object
if (
target[ReactiveFlags.RAW] &&
!(isReadonly && target[ReactiveFlags.IS_REACTIVE])
) {
return target
}
// only specific value types can be observed.
const targetType = getTargetType(target)
if (targetType === TargetType.INVALID) {
return target
}
// target already has corresponding Proxy
const existingProxy = proxyMap.get(target)
if (existingProxy) {
return existingProxy
}
const proxy = new Proxy(
target,
targetType === TargetType.COLLECTION ? collectionHandlers : baseHandlers,
)
proxyMap.set(target, proxy)
return proxy
}
/**
* Checks if an object is a proxy created by {@link reactive()} or
* {@link shallowReactive()} (or {@link ref()} in some cases).
*
* @example
* ```js
* isReactive(reactive({})) // => true
* isReactive(readonly(reactive({}))) // => true
* isReactive(ref({}).value) // => true
* isReactive(readonly(ref({})).value) // => true
* isReactive(ref(true)) // => false
* isReactive(shallowRef({}).value) // => false
* isReactive(shallowReactive({})) // => true
* ```
*
* @param value - The value to check.
* @see {@link https://vuejs.org/api/reactivity-utilities.html#isreactive}
*/
export function isReactive(value: unknown): boolean {
if (isReadonly(value)) {
return isReactive((value as Target)[ReactiveFlags.RAW])
}
return !!(value && (value as Target)[ReactiveFlags.IS_REACTIVE])
}
/**
* Checks whether the passed value is a readonly object. The properties of a
* readonly object can change, but they can't be assigned directly via the
* passed object.
*
* The proxies created by {@link readonly()} and {@link shallowReadonly()} are
* both considered readonly, as is a computed ref without a set function.
*
* @param value - The value to check.
* @see {@link https://vuejs.org/api/reactivity-utilities.html#isreadonly}
*/
export function isReadonly(value: unknown): boolean {
return !!(value && (value as Target)[ReactiveFlags.IS_READONLY])
}
export function isShallow(value: unknown): boolean {
return !!(value && (value as Target)[ReactiveFlags.IS_SHALLOW])
}
/**
* Checks if an object is a proxy created by {@link reactive},
* {@link readonly}, {@link shallowReactive} or {@link shallowReadonly()}.
*
* @param value - The value to check.
* @see {@link https://vuejs.org/api/reactivity-utilities.html#isproxy}
*/
export function isProxy(value: any): boolean {
return value ? !!value[ReactiveFlags.RAW] : false
}
/**
* Returns the raw, original object of a Vue-created proxy.
*
* `toRaw()` can return the original object from proxies created by
* {@link reactive()}, {@link readonly()}, {@link shallowReactive()} or
* {@link shallowReadonly()}.
*
* This is an escape hatch that can be used to temporarily read without
* incurring proxy access / tracking overhead or write without triggering
* changes. It is **not** recommended to hold a persistent reference to the
* original object. Use with caution.
*
* @example
* ```js
* const foo = {}
* const reactiveFoo = reactive(foo)
*
* console.log(toRaw(reactiveFoo) === foo) // true
* ```
*
* @param observed - The object for which the "raw" value is requested.
* @see {@link https://vuejs.org/api/reactivity-advanced.html#toraw}
*/
export function toRaw<T>(observed: T): T {
const raw = observed && (observed as Target)[ReactiveFlags.RAW]
return raw ? toRaw(raw) : observed
}
export type Raw<T> = T & { [RawSymbol]?: true }
/**
* Marks an object so that it will never be converted to a proxy. Returns the
* object itself.
*
* @example
* ```js
* const foo = markRaw({})
* console.log(isReactive(reactive(foo))) // false
*
* // also works when nested inside other reactive objects
* const bar = reactive({ foo })
* console.log(isReactive(bar.foo)) // false
* ```
*
* **Warning:** `markRaw()` together with the shallow APIs such as
* {@link shallowReactive()} allow you to selectively opt-out of the default
* deep reactive/readonly conversion and embed raw, non-proxied objects in your
* state graph.
*
* @param value - The object to be marked as "raw".
* @see {@link https://vuejs.org/api/reactivity-advanced.html#markraw}
*/
export function markRaw<T extends object>(value: T): Raw<T> {
if (!hasOwn(value, ReactiveFlags.SKIP) && Object.isExtensible(value)) {
def(value, ReactiveFlags.SKIP, true)
}
return value
}
/**
* Returns a reactive proxy of the given value (if possible).
*
* If the given value is not an object, the original value itself is returned.
*
* @param value - The value for which a reactive proxy shall be created.
*/
export const toReactive = <T extends unknown>(value: T): T =>
isObject(value) ? reactive(value) : value
/**
* Returns a readonly proxy of the given value (if possible).
*
* If the given value is not an object, the original value itself is returned.
*
* @param value - The value for which a readonly proxy shall be created.
*/
export const toReadonly = <T extends unknown>(value: T): DeepReadonly<T> =>
isObject(value) ? readonly(value) : (value as DeepReadonly<T>)