使用put内部匿名函数回调

Question

我正在将Pusher实现到我的React + Redux Saga应用程序中,但是我遇到了一些问题,我在一些回调中遇不到这些put(...)方法.console.log(...)在方法中使用等确实显示,但我无法进入put我的应用程序状态.

我在异步/生成器函数的一些实现上可能是错的,但我现在几乎被卡住了.

我的代码说明了什么不会触发:

import { takeLatest } from 'redux-saga'
import { call, put } from 'redux-saga/effects'

// Pusher actions
export const pusherConnecting = () => {
    return {
        type: ActionTypes.PUSHER_CONNECTING
    }
};

export const pusherConnectSucceeded = (client) => {
    return {
        type: ActionTypes.PUSHER_CONNECT_SUCCEEDED,
        client: client
    }
};

const pusherConnectFailed = (exception) => {
    return {
        type: ActionTypes.PUSHER_CONNECT_FAILED,
        message: exception
    }
};

// Pusher Saga
function * connectPusher(action) {
    try {
        const pusher = yield call(Api.connectPusher, action.directory, function(subscription) {
            subscription.bind(PUSHER_BIND_RELOAD, function() {
                location.reload(true);
            });

            subscription.bind(PUSHER_BIND_REQUEST_DATA, function(data) {
                if (data) {
                    put(updateDirectory(data));
                } else {
                    put(requestDirectory(action.directory.id));
                }
            });
        });

        pusher.connection.bind('connected', function() {
            put(pusherConnectSucceeded(pusher));
        });

        yield put(pusherConnecting());

    } catch (e) {
        yield put(pusherConnectFailed(e));
    }
}

export default function * pusherSaga() {
    yield * takeLatest(ActionTypes.DIRECTORY_FETCH_SUCCEEDED, connectPusher);
}



// My Api.ConnectPusher
export function * connectPusher(directory, subscription) {
    var pusher = new Pusher(PUSHER_KEY, {
        encrypted: true
    });

    var channels = ["test1", "test2"  ];

    for (var i = 0; i < channels.length; i++) {
        // Take each channel and callback with the subscription
        yield subscription(pusher.subscribe(channels[i]));
    }

    return pusher;
}

基于@Sebastien的解决方案

yield put(yield onConnect(pusher));

function onConnect(pusher) {
    return new Promise((resolve, reject) => {
        pusher.connection.bind('connected', function() {
            resolve(pusherConnectSucceeded(pusher));
        });
    });
}

Answer 1

Redux-saga不允许put不使用关键字yield.put创建了一个必须被解释/执行的简单json对象/效果,如果你不屈服则不会.

此外,即使使用yield put(...),如果这是在回调中完成的,也不会被解释,因为Redux-saga没有能力在其解释器中运行回调.它们只是作为正常的回调运行,什么都不会发生.

如果subscription.bind应该返回单个结果,则可以将该调用包装为返回promise的函数,然后生成该promise.

如果subscription.bind应该返回结果流,则可能需要而不是创建通道.我想将来有人会发布一些可以轻松允许将Observable转换为Redux-saga流的东西

请注意,如果您不需要多次取消订阅/重新订阅,那么将此代码置于传奇之外可能更为简单,只需执行此操作

        subscription.bind(PUSHER_BIND_RELOAD, function() {
            location.reload(true);
        });

        subscription.bind(PUSHER_BIND_REQUEST_DATA, function(data) {
            if (data) {
                reduxStore.dispatch(updateDirectory(data));
            } else {
                reduxStore.dispatch((requestDirectory(action.directory.id));
            }
        });