@tanstack/store/dist/cjs/derived.cjs

Framework agnostic type-safe store w/ reactive framework adapters

"use strict";
Object.defineProperty(exports, Symbol.toStringTag, { value: "Module" });
const store = require("./store.cjs");
const scheduler = require("./scheduler.cjs");
class Derived {
  constructor(options) {
    this.listeners = /* @__PURE__ */ new Set();
    this._subscriptions = [];
    this.lastSeenDepValues = [];
    this.getDepVals = () => {
      const prevDepVals = [];
      const currDepVals = [];
      for (const dep of this.options.deps) {
        prevDepVals.push(dep.prevState);
        currDepVals.push(dep.state);
      }
      this.lastSeenDepValues = currDepVals;
      return {
        prevDepVals,
        currDepVals,
        prevVal: this.prevState ?? void 0
      };
    };
    this.recompute = () => {
      var _a, _b;
      this.prevState = this.state;
      const { prevDepVals, currDepVals, prevVal } = this.getDepVals();
      this.state = this.options.fn({
        prevDepVals,
        currDepVals,
        prevVal
      });
      (_b = (_a = this.options).onUpdate) == null ? void 0 : _b.call(_a);
    };
    this.checkIfRecalculationNeededDeeply = () => {
      for (const dep of this.options.deps) {
        if (dep instanceof Derived) {
          dep.checkIfRecalculationNeededDeeply();
        }
      }
      let shouldRecompute = false;
      const lastSeenDepValues = this.lastSeenDepValues;
      const { currDepVals } = this.getDepVals();
      for (let i = 0; i < currDepVals.length; i++) {
        if (currDepVals[i] !== lastSeenDepValues[i]) {
          shouldRecompute = true;
          break;
        }
      }
      if (shouldRecompute) {
        this.recompute();
      }
    };
    this.mount = () => {
      this.registerOnGraph();
      this.checkIfRecalculationNeededDeeply();
      return () => {
        this.unregisterFromGraph();
        for (const cleanup of this._subscriptions) {
          cleanup();
        }
      };
    };
    this.subscribe = (listener) => {
      var _a, _b;
      this.listeners.add(listener);
      const unsub = (_b = (_a = this.options).onSubscribe) == null ? void 0 : _b.call(_a, listener, this);
      return () => {
        this.listeners.delete(listener);
        unsub == null ? void 0 : unsub();
      };
    };
    this.options = options;
    this.state = options.fn({
      prevDepVals: void 0,
      prevVal: void 0,
      currDepVals: this.getDepVals().currDepVals
    });
  }
  registerOnGraph(deps = this.options.deps) {
    for (const dep of deps) {
      if (dep instanceof Derived) {
        dep.registerOnGraph();
        this.registerOnGraph(dep.options.deps);
      } else if (dep instanceof store.Store) {
        let relatedLinkedDerivedVals = scheduler.__storeToDerived.get(dep);
        if (!relatedLinkedDerivedVals) {
          relatedLinkedDerivedVals = /* @__PURE__ */ new Set();
          scheduler.__storeToDerived.set(dep, relatedLinkedDerivedVals);
        }
        relatedLinkedDerivedVals.add(this);
        let relatedStores = scheduler.__derivedToStore.get(this);
        if (!relatedStores) {
          relatedStores = /* @__PURE__ */ new Set();
          scheduler.__derivedToStore.set(this, relatedStores);
        }
        relatedStores.add(dep);
      }
    }
  }
  unregisterFromGraph(deps = this.options.deps) {
    for (const dep of deps) {
      if (dep instanceof Derived) {
        this.unregisterFromGraph(dep.options.deps);
      } else if (dep instanceof store.Store) {
        const relatedLinkedDerivedVals = scheduler.__storeToDerived.get(dep);
        if (relatedLinkedDerivedVals) {
          relatedLinkedDerivedVals.delete(this);
        }
        const relatedStores = scheduler.__derivedToStore.get(this);
        if (relatedStores) {
          relatedStores.delete(dep);
        }
      }
    }
  }
}
exports.Derived = Derived;
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