Question

我能够实现以下目标 - ＆gt;当用户点击组件A中的特定日期时，数据将被发送到节点（Sails API），在那里完成所有必要的计算，并且在呈现组件B之前，可以显示正确的数据。

问题是当用户从组件B返回到组件A并选择不同的日期时，他/她得到完全相同的结果（旧值），因为即使将新值发送到后端API，Node也不是用新值重新计算。

我只能在手动刷新页面后才能获得正确的结果，或者对服务器进行更改以强制重新计算。

我想我需要提一下，我正在使用Redux传递数据，所以可能会出现问题。

我会考虑某种类型的自动刷新，动画加载，任何东西。是的，所以卡住了：/

甚至可以让它们完全同步吗？

更新 - ＆gt;这是代码：

BACKEND

getDetails: (req, res) => {
    authentication.authenticate().then((auth) => {
      const sheets = google.sheets('v4');
      sheets.spreadsheets.values.get({
        auth: auth,
        spreadsheetId: config.spreadsheetSettings.spreadsheetId, // id of spreadsheet
        range: config.spreadsheetSettings.employeeSheetId, // name of employee spreadsheet and range- get all cells
      }, (err, response) => {
        if (err) {
          res.serverError(err);
          return;
        }
        const rows = response.values; // response-all cells
        const updatedData = employeeService.mapEmployeeSheetToJson(rows);

         // FETCHING THE VALUE FROM REST API
        let myArr = [];

        (function() {

                    axios.get(`http://localhost:1337/api/`)
                    .then(res =>  {
                    let kajmak = res.data.slice(-1)[0]
                    let test = kajmak[Object.keys(kajmak)[0]]
                    myArr.push(test)
                    }).catch(err => console.error(err));
             })();

        // MAPING OVER THE ARRY AND DOING THE LOGIC
        setTimeout(() => {
            myArr.map(xo => {

        const result = [];

    updatedData.forEach(emp => {//  2013     2012  2014
        if (xo > parseInt(moment(emp.startdate).format('YYYYMM'), 10) &&
          (xo < parseInt(moment(emp.enddate).format('YYYYMM'), 10))) {
              result.push(emp);
          }
      });

      // IF THEY STARTED WORKING BEFORE THE SELECTED DATE AND STILL WORKING
    updatedData.forEach(emp => { // 2013   > 2012 & 2013   -
          if (xo > parseInt(moment(emp.startdate).format('YYYYMM'), 10) && 
              ((parseInt(moment(emp.enddate).format('YYYYMM'), 10) == undefined ))) {
                  result.push(emp);
          }
      });

      // IF THEY STARTED WORKIG BEFORE THE SELECTED DATE,
      // BUT STOPPED WORKING BEFORE THE SELECTED DATE
    updatedData.forEach(emp => {  // 2013  <    2014 ||     2013  > 2017
          if (xo < parseInt(moment(emp.startdate).format('YYYYMM'), 10) &&
              (xo > parseInt(moment(emp.startdate).format('YYYYMM'), 10))) {
                  result.pop(emp);
          }
      });

        // Getting the names to use for unique sheet req
        let finalResult = [];
        result.map(x => {
            finalResult.push((x.name + ' ' + x.surname))
        })

        if (rows.length === 0) {
          res.err('No data found.');
        } else {
          res.ok(finalResult);
        }
    }) 
        }, 1000);
    });

}

FRONTEND

getEmployeeSalaryData = () => {
            // GETTING THE CLICKED VALUE FROM THE PREVIOUS COMPONENT
            const { year } = this.props.history.location.state.item;
            const { month } = this.props.history.location.state.item;
            const selectedMonth = moment().month(month).format("MM");
            const finalSelect = parseInt(year + selectedMonth, 10);
            const { employees } = this.props;
            // I'M RECIEVING THIS AS PROPS USING REDUX AND THIS IS THE ACTUAL 'FINAL' DATA USED FOR FURTHER CALCS AND RENDERING
            const { details } = this.props;

             // HERE I'M SENDING THE 'CLICKED' VALUE FROM THE PREVIOUS COMPONENT TO THE BACKEND API
            axios.post(`http://localhost:1337/api/`, { 'test' : finalSelect })
                .then(res => {
                console.log('Data send')
                // console.log(res.data);
              }).catch(err => console.error(err));



            // Making the req 
            details.map(x => {

                EmployeeApi.getEmployee(x)
                    .then(y => {
                        //Making sure everything is in the right order
                        let test = Object.assign(y.data);
                        let ii = x;

                    setTimeout(
                        this.setState(prevState => ({
                            ...prevState.currentEmployee,
                            fullNames: [...prevState.currentEmployee.fullNames, ii]
                        })), 100);

                let onlyRelevantDate = [];
                test.map(item => {
                    if (finalSelect == parseInt(item.year + moment().month(item.month).format("MM"), 10)) {
                            onlyRelevantDate.push(item)
                        }})
                            this.setState(prevState => ({
                            currentEmployee: {
                            ...prevState.currentEmployee,
                            salaryInfo: [...prevState.currentEmployee.salaryInfo, onlyRelevantDate],
                            fullNames: [...prevState.currentEmployee.fullNames, ii]
                    }}))         
                })
            });
        }   
        componentWillReceiveProps(nextProps) {
            this.getEmployeeSalaryData(nextProps);
        }

        componentWillMount() {
            this.getEmployeeSalaryData(this.props);
        }

Answer 1

在组件A中，您应该调度一个采用调度函数的函数。

//some click handler for when user makes a selection
//  the function should be in action creator file but you get the jist
const handleSomeClick = someValue =>
  //when you dispatch an action that is a function in redux with thunk then
  //  the thunk middleware will not call next (no reducers will be called)
  //  thunk will pass a parameter to this function that is the dispatch
  //  function so from your function you can dispatch actual object action(s)
  dispatch(
    dispatch=>
      setTimeout(
        dispatch({type:"changedValue",data:someValue}),//dispatching the action
        someValue*1000//assuming someValue is a number
      )
  )

Here是一个示例，其组件A设置为someValue，具体取决于单击的按钮，并突出显示该按钮，它还将异步设置B的someValue。这是在调用一个函数的函数changeLater中完成的，因此thunk将使用调度执行它。

此功能将在超时后调度操作。如果单击数字5然后单击1（快速），您将看到A的突出显示按钮和B的异步后的值不匹配（A的突出显示为1，B的异步显示为5后的值）。

这是因为用户单击并启动异步进程的顺序与异步进程解析的顺序不同。您可以通过仅在最后解决的承诺时调度操作来解决此问题。

This example显示了如何使用later创建的承诺，只有在使用onlyLastRequestedPromise的部分应用版lastNumberClicked < / p>

Answer 2

您可以使用RxJS解决此问题

节点和React不同步

2 个答案: