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{"version":3,"file":"signals.js","sources":["../src/index.ts"],"sourcesContent":["import { options, Component } from \"preact\";\nimport { useRef, useMemo, useEffect } from \"preact/hooks\";\nimport {\n\tsignal,\n\tcomputed,\n\tbatch,\n\teffect,\n\tSignal,\n\ttype ReadonlySignal,\n} from \"@preact/signals-core\";\nimport {\n\tVNode,\n\tOptionsTypes,\n\tHookFn,\n\tEffect,\n\tPropertyUpdater,\n\tAugmentedComponent,\n\tAugmentedElement as Element,\n} from \"./internal\";\n\nexport { signal, computed, batch, effect, Signal, type ReadonlySignal };\n\nconst HAS_PENDING_UPDATE = 1 << 0;\nconst HAS_HOOK_STATE = 1 << 1;\nconst HAS_COMPUTEDS = 1 << 2;\n\n// Install a Preact options hook\nfunction hook<T extends OptionsTypes>(hookName: T, hookFn: HookFn<T>) {\n\t// @ts-ignore-next-line private options hooks usage\n\toptions[hookName] = hookFn.bind(null, options[hookName] || (() => {}));\n}\n\nlet currentComponent: AugmentedComponent | undefined;\nlet finishUpdate: (() => void) | undefined;\n\nfunction setCurrentUpdater(updater?: Effect) {\n\t// end tracking for the current update:\n\tif (finishUpdate) finishUpdate();\n\t// start tracking the new update:\n\tfinishUpdate = updater && updater._start();\n}\n\nfunction createUpdater(update: () => void) {\n\tlet updater!: Effect;\n\teffect(function (this: Effect) {\n\t\tupdater = this;\n\t});\n\tupdater._callback = update;\n\treturn updater;\n}\n\n/** @todo This may be needed for complex prop value detection. */\n// function isSignalValue(value: any): value is Signal {\n// \tif (typeof value !== \"object\" || value == null) return false;\n// \tif (value instanceof Signal) return true;\n// \t// @TODO: uncomment this when we land Reactive (ideally behind a brand check)\n// \t// for (let i in value) if (value[i] instanceof Signal) return true;\n// \treturn false;\n// }\n\n/**\n * A wrapper component that renders a Signal directly as a Text node.\n * @todo: in Preact 11, just decorate Signal with `type:null`\n */\nfunction Text(this: AugmentedComponent, { data }: { data: Signal }) {\n\t// hasComputeds.add(this);\n\n\t// Store the props.data signal in another signal so that\n\t// passing a new signal reference re-runs the text computed:\n\tconst currentSignal = useSignal(data);\n\tcurrentSignal.value = data;\n\n\tconst s = useMemo(() => {\n\t\t// mark the parent component as having computeds so it gets optimized\n\t\tlet v = this.__v;\n\t\twhile ((v = v.__!)) {\n\t\t\tif (v.__c) {\n\t\t\t\tv.__c._updateFlags |= HAS_COMPUTEDS;\n\t\t\t\tbreak;\n\t\t\t}\n\t\t}\n\n\t\t// Replace this component's vdom updater with a direct text one:\n\t\tthis._updater!._callback = () => {\n\t\t\t(this.base as Text).data = s.peek();\n\t\t};\n\n\t\treturn computed(() => {\n\t\t\tlet data = currentSignal.value;\n\t\t\tlet s = data.value;\n\t\t\treturn s === 0 ? 0 : s === true ? \"\" : s || \"\";\n\t\t});\n\t}, []);\n\n\treturn s.value;\n}\nText.displayName = \"_st\";\n\nObject.defineProperties(Signal.prototype, {\n\tconstructor: { configurable: true },\n\ttype: { configurable: true, value: Text },\n\tprops: {\n\t\tconfigurable: true,\n\t\tget() {\n\t\t\treturn { data: this };\n\t\t},\n\t},\n\t// Setting a VNode's _depth to 1 forces Preact to clone it before modifying:\n\t// https://github.com/preactjs/preact/blob/d7a433ee8463a7dc23a05111bb47de9ec729ad4d/src/diff/children.js#L77\n\t// @todo remove this for Preact 11\n\t__b: { configurable: true, value: 1 },\n});\n\n/** Inject low-level property/attribute bindings for Signals into Preact's diff */\nhook(OptionsTypes.DIFF, (old, vnode) => {\n\tif (typeof vnode.type === \"string\") {\n\t\tlet signalProps: Record<string, any> | undefined;\n\n\t\tlet props = vnode.props;\n\t\tfor (let i in props) {\n\t\t\tif (i === \"children\") continue;\n\n\t\t\tlet value = props[i];\n\t\t\tif (value instanceof Signal) {\n\t\t\t\tif (!signalProps) vnode.__np = signalProps = {};\n\t\t\t\tsignalProps[i] = value;\n\t\t\t\tprops[i] = value.peek();\n\t\t\t}\n\t\t}\n\t}\n\n\told(vnode);\n});\n\n/** Set up Updater before rendering a component */\nhook(OptionsTypes.RENDER, (old, vnode) => {\n\t
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