Question

编辑1

所以我现在更新了projectorSaga函数以使用yield call（），但我现在每次调用函数时都会收到以下错误，我认为这是由于我嵌套函数和返回promise的方式不是返回承诺的函数，但我对如何重组它来修复它有点不知所措。

redux-saga error: uncaught at check
call: argument [object Promise] is not a function
[14:57:43.351] [verbose] Error: call: argument [object Promise] is not a function

这里是更新传奇代码，其他功能仍然如下。

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

import * as pjControl from '../../pjcontrol/pjControl';

import { TURNON, TURNOFF, SENDCOMMAND, SHUTTERCLOSE, SHUTTEROPEN } from '../actions/actionTypes';

const log = require('electron-log');

const ip = '192.168.100.100';
const port = 3629;
const model = 'L1500';

function* sendCommand(payload) {
  yield put({ type: 'SENDING COMMAND', payload });
  try {
    let response;
    const command = payload.payload.command;
    if (command === TURNON) {
      response = yield call(pjControl.turnOn(ip, port, model));
    } else if (command === TURNOFF) {
      response = yield call(pjControl.turnOff(ip, port, model));
    } else if (command === SHUTTERCLOSE) {
      response = yield call(pjControl.shutterClose(ip, port, model));
    } else if (command === SHUTTEROPEN) {
      response = yield call(pjControl.shutterOpen(ip, port, model));
    } else {
      throw Error('Unknwon Command');
    }
    log.verbose(response);
    yield put({ type: 'SEND_COMMAND_SUCCEEDED', response });
  } catch (e) {
    log.verbose(e);
    yield put({ type: 'SEND_COMMAND_FAILED', e });
  }
}

export default function* projectorSetSaga() {
  yield takeEvery(SENDCOMMAND, sendCommand);
}

原始

我刚刚开始尝试在我正在使用的Electron应用程序中使用Redux-Saga，而且我在使用其中一个生成器函数时遇到问题。我怀疑我不理解所说的函数和回调e.t.c的嵌套，但到目前为止我已经在很多方面试过这个并没有区别。

问题的奇怪之处在于sendCommand中的初始yield会导致事件出现在Redux中。我所使用的日志命令也会在我期望它们时被调用，并且具有正确的值。如果连接超时，则会调用catch中的日志，但是两个throw命令都不会出现在Redux中。

这是我的根佐贺：

import { all, call } from 'redux-saga/effects';

import projectorGetSaga from './projectorGetSaga';
import projectorSetSaga from './projectorSetSaga';

export default function* rootSaga() {
  yield all([
    call(projectorGetSaga),
    call(projectorSetSaga),
  ]);
}

这是投影机设备，我正在努力奋斗。

import { put, takeEvery } from 'redux-saga/effects';

import * as pjControl from '../../pjcontrol/pjControl';

import { TURNON, TURNOFF, SENDCOMMAND, SHUTTERCLOSE, SHUTTEROPEN } from '../actions/actionTypes';

const log = require('electron-log');

const ip = '192.168.100.100';
const port = 3629;
const model = 'L1500';

function* sendCommand(payload) {
  yield put({ type: 'SENDING COMMAND', payload });
  try {
    let response;
    const command = payload.payload.command;
    if (command === TURNON) {
      response = yield pjControl.turnOn(ip, port, model);
    } else if (command === TURNOFF) {
      response = yield pjControl.turnOff(ip, port, model);
    } else if (command === SHUTTERCLOSE) {
      response = yield pjControl.shutterClose(ip, port, model);
    } else if (command === SHUTTEROPEN) {
      response = yield pjControl.shutterOpen(ip, port, model);
    } else {
      throw Error('Unknwon Command');
    }
    log.verbose(response);
    yield put({ type: 'SEND_COMMAND_SUCCEEDED', response });
  } catch (e) {
    log.verbose(e);
    yield put({ type: 'SEND_COMMAND_FAILED', e });
  }
}

export default function* projectorSetSaga() {
  yield takeEvery(SENDCOMMAND, sendCommand);
}

以下是saga调用的函数的其余代码，因为它可能是相关的，我可能完全误解了async函数/ promises e.t.c需要返回的方式。

sendCommand函数调用的PJ Control函数如下所示。

import * as epsonControl from './epson/epsonControl';
import { manufacturerlLookup, commandLookup } from './pjLookups';

function sendCommand(ip, port, model, command, input) {
  const manufacturer = manufacturerlLookup(model);
  const mappedCommand = commandLookup(manufacturer, command, input);
  switch (manufacturer) {
    case 'epson':
      return epsonControl.sendCommand(ip, port, mappedCommand);
    default:
      return null;
  }
}




exports.turnOn = (ip, port, model) => sendCommand(ip, port, model, 'PWR ON');

exports.turnOff = (ip, port, model) => sendCommand(ip, port, model, 'PWR OFF');

exports.shutterOpen = (ip, port, model) => sendCommand(ip, port, model, 'MUTE OFF');

exports.shutterClose = (ip, port, model) => sendCommand(ip, port, model, 'MUTE ON');

exports.setInput = (ip, port, model, input) => sendCommand(ip, port, model, 'SOURCE', input);

exports.getPowerStatus = (ip, port, model) => sendCommand(ip, port, model, 'PWR?');

exports.getShutterStatus = (ip, port, model) => sendCommand(ip, port, model, 'MUTE?');

exports.getInputStatus = (ip, port, model) => sendCommand(ip, port, model, 'SOURCE?');

最后，实际的异步函数，实际上是返回一个带有return / throw的promise。

exports.sendCommand = async (host, port, command) => {
  log.info(`sending command ${command} to ${host}`);

  // throw new Error('Oh dear!');
  // Set a time to cancel the operation if the connection times out
  const mergedCommand = `${command}\r`;
  // Create a new client
  const socket = new net.Socket();

  socket.setTimeout(1000);

  const client = new PromiseSocket(socket);

  await client.connect({ host, port });

  await client.write(buildBuffer(handshake));

  client.stream.on('data', (data) => {
    if (data.toString() === response) {
      log.verbose(`Got handshake, sending command ${command}`);
      client.write(buildBuffer(mergedCommand));
    } else if (data.toString() === ':') {
      // log.verbose('command executed successfully, disconnecting');
      sendStatus(data.toString(), host);
      client.end();
      return (true, 'command');
    } else {
      const respose = data.toString().substring(0, data.toString().length - 2);
      // log.verbose(`got status ${response} disconnecting`);
      sendStatus(respose, host);
      client.end();
      return (true, 'command', data);
    }
  });
};

Answer 1

我认为你是yielding（暂停）生成器函数而不调用它的下一个。佐贺有这方面的功能。例如，不是在函数调用上产生，而是在saga函数call上产生。

所以它应该是：

 try {
    let response;
    const command = payload.payload.command;
    if (command === TURNON) {
      response = yield call([pjControl,'turnOn'],ip, port, model);
    } 
 ...

请参阅https://redux-saga.js.org/docs/api/

无法让Redux在生成器函数

1 个答案: