react-use-subject/dist/index.mjs

A React hook for managing and subscribing to state changes using RxJS Subjects.

import { Subject } from 'rxjs';
import { useState, useEffect } from 'react';

/******************************************************************************
Copyright (c) Microsoft Corporation.

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
***************************************************************************** */
/* global Reflect, Promise, SuppressedError, Symbol, Iterator */


function __classPrivateFieldGet(receiver, state, kind, f) {
    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
}

function __classPrivateFieldSet(receiver, state, value, kind, f) {
    if (kind === "m") throw new TypeError("Private method is not writable");
    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
    return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
}

typeof SuppressedError === "function" ? SuppressedError : function (error, suppressed, message) {
    var e = new Error(message);
    return e.name = "SuppressedError", e.error = error, e.suppressed = suppressed, e;
};

var _ReplaySubject_cache, _ReplaySubject_cacheSize;
class ReplaySubject extends Subject {
    /**
     * 构造函数
     * @param cacheSize 缓存大小
     * @param initVal 初始数据
     */
    constructor(cacheSize = 1, initVal) {
        super();
        /**
         * 历史数据
         */
        _ReplaySubject_cache.set(this, []);
        /**
         * 缓存大小
         */
        _ReplaySubject_cacheSize.set(this, 1);
        __classPrivateFieldSet(this, _ReplaySubject_cacheSize, cacheSize, "f");
        if (initVal) {
            this.next(initVal);
        }
    }
    /**
     * 创建一个 ReplaySubject 实例
     * @param v 初始数据
     * @returns ReplaySubject 实例
     */
    static create(v) {
        return new ReplaySubject(1, v);
    }
    /**
     *
     * @param value 新数据
     * @returns
     */
    next(value) {
        __classPrivateFieldGet(this, _ReplaySubject_cache, "f").push(value);
        // 如果cache数组的长度大于cacheSize，则删除第一个元素（LRU）
        if (__classPrivateFieldGet(this, _ReplaySubject_cache, "f").length > __classPrivateFieldGet(this, _ReplaySubject_cacheSize, "f")) {
            __classPrivateFieldGet(this, _ReplaySubject_cache, "f").shift();
        }
        super.next(value);
        return this;
    }
    /**
     * 重写 subscribe 方法，订阅时立即调用回调并传递当前值（如果有缓存），并打印当前值
     */
    subscribe(callback) {
        if (__classPrivateFieldGet(this, _ReplaySubject_cache, "f").length > 0) {
            callback(this.getLast());
        }
        return super.subscribe(callback);
    }
    /**
     * @deprecated
     * @param val
     * 建议使用显式的 next 替代
     */
    set value(val) {
        console.warn("set value is deprecated, please use next instead");
        this.next(val);
    }
    /**
     * 获取最新（最后）数据
     * @returns
     */
    getLast() {
        if (__classPrivateFieldGet(this, _ReplaySubject_cache, "f").length === 0) {
            throw new Error("No data");
        }
        return __classPrivateFieldGet(this, _ReplaySubject_cache, "f")[__classPrivateFieldGet(this, _ReplaySubject_cache, "f").length - 1];
    }
    /**
     * 获取历史数据
     * @returns 历史数据
     */
    getHistory() {
        return [...__classPrivateFieldGet(this, _ReplaySubject_cache, "f")];
    }
}
_ReplaySubject_cache = new WeakMap(), _ReplaySubject_cacheSize = new WeakMap();

// 定义一个泛型函数useSubject，接收一个参数subject
function useSubject(subject) {
    const [value, setValue] = useState(subject.getLast());
    useEffect(() => {
        const subscription = subject.subscribe(setValue);
        return () => {
            subscription.unsubscribe();
        };
    });
    return value;
}

export { ReplaySubject, useSubject };