在回调函数中导出模块? [英] exporting a module in a callback function?

问题描述

有没有一种方法可以导出回调函数中的某些变量?例如，如果我需要在另一个文件中使用room.room_id，该怎么办?我试过module.exports.roomId = room.room_id，但另一个文件中的roomId似乎未定义.谢谢！

is there a way to export some variables that are inside a callback function? for example, if i need to use room.room_id in another file, what should i do? i tried module.exports.roomId = room.room_id but roomId in another file appeared to be undefined.thanks!

var Room = require('../models/database').Room

exports.create = function (req, res) {


Room
    .create({
        room_name: req.body.roomName
    })
    .complete(function () {

        Room
            .find({where: {room_name: req.body.roomName}})
            .success(function (room) {

                // if(err) console.log(err);

                res.redirect('rooms/videochat/' + req.body.roomName + '/' + room.room_id);
                console.log("room_id: " + room.room_id);

                module.exports.roomId = room.room_id;
        })

    })

};

推荐答案

您不能那样做，因为模块是同步评估的，并且将来会更改module.exports.您需要做的是提供一个回调，然后传入值或将回调用作可以成功从导出的属性中读取的指示符.

You can't do it like that because modules are evaluated synchronously and you're mutating module.exports some time in the future. What you need to do is supply a callback and either pass the value in or use the callback as an indicator that you can successfully read from the exported property.

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