@chrfalch/react-observable-context/dist/index.mjs

Observable context for React

// src/library/createContext.ts
import React from "react";

// src/library/makeObservable.ts
var makeObservable = (initialValue) => {
  const listeners = /* @__PURE__ */ new Map();
  const subscribe = (prop, listener) => {
    if (!listeners.has(prop)) {
      listeners.set(prop, [listener]);
    } else {
      listeners.get(prop)?.push(listener);
    }
    return () => {
      const index = listeners.get(prop)?.indexOf(listener);
      if (index !== void 0 && index > -1) {
        listeners.get(prop)?.splice(index, 1);
      }
    };
  };
  const notify = (key) => {
    const cb = listeners.get(key);
    cb?.forEach((c) => c());
    const parentKey = key.toString().split(".").slice(0, -1).join(".");
    if (parentKey) {
      notify(parentKey);
    }
  };
  const internalWrap = (object, parentKey = "") => {
    return new Proxy(object, {
      get: (target, prop, receiver) => {
        if (parentKey === "" && prop === "subscribe") {
          return subscribe;
        } else if (typeof prop === "symbol") {
          return Reflect.get(target, prop, receiver);
        } else {
          const value = Reflect.get(target, prop, receiver);
          if (value && (typeof value === "object" || Array.isArray(value))) {
            return internalWrap(
              value,
              parentKey + (parentKey ? "." : "") + prop
            );
          } else {
            return Reflect.get(target, prop, receiver);
          }
        }
      },
      set: (target, prop, value, receiver) => {
        const retVal = Reflect.set(target, prop, value, receiver);
        if (retVal && typeof prop !== "symbol") {
          const key = parentKey + (parentKey ? "." : "") + prop;
          notify(key);
        }
        return retVal;
      }
    });
  };
  return internalWrap(initialValue);
};

// src/library/createContext.ts
var createContext = (obj) => React.createContext(obj ? makeObservable(obj) : void 0);

// src/library/useObserver.ts
import { useEffect, useState } from "react";

// src/library/utils.ts
var resolve = (obj, path) => path.split(".").reduce((p, c) => {
  return p?.[c];
}, obj);
var flatten = (obj, parentKey) => {
  let result = {};
  Object.entries(obj).forEach(([key, value]) => {
    const flattenedKey = parentKey ? parentKey + "." + key : key;
    if (value instanceof Array) {
      result = {
        ...result,
        [flattenedKey]: value,
        [`${flattenedKey}.length`]: value.length,
        ...flatten(
          value,
          flattenedKey
        )
      };
    } else if (typeof value === "object") {
      result = {
        ...result,
        ...flatten(value, flattenedKey)
      };
    } else {
      result[flattenedKey] = value;
    }
  });
  return result;
};
function extract(obj, ...keys) {
  return keys.reduce((newObj, curr) => {
    newObj[curr] = obj[curr];
    return newObj;
  }, {});
}

// src/library/useObserver.ts
var useObserver = (observable, ...props) => {
  const [_, inc] = useState(0);
  const [state, setState] = useState(
    () => flattenAndExtract(
      observable,
      props
    )
  );
  useEffect(() => {
    const unsubscribers = props.map((prop) => {
      return observable.subscribe(prop, () => {
        inc((p) => p + 1);
        setState((p) => ({
          ...p,
          // eslint-disable-next-line @typescript-eslint/ban-ts-comment
          // @ts-ignore
          [prop]: resolve(observable, prop)
        }));
      });
    });
    return () => unsubscribers.forEach((un) => un());
  }, [observable, props]);
  return state;
};
function flattenAndExtract(value, props) {
  const flattenedObject = flatten(value);
  return extract(
    flattenedObject,
    ...props
  );
}

// src/library/useObservable.ts
import { useMemo } from "react";
var useObservable = (initialValue) => {
  return useMemo(() => {
    return makeObservable(initialValue);
  }, []);
};

// src/index.ts
var Observable = {
  createContext,
  makeObservable,
  useObserver,
  useObservable
};
var src_default = Observable;
export {
  Observable,
  createContext,
  src_default as default,
  makeObservable,
  useObservable,
  useObserver
};