接收POST请求并编辑JSON文件NodeJS

在NodeJS中收到来自客户端的POST请求后，无法弄清楚如何编辑我的json文件。

使用webix数据表。 在我更新表中的数据后，它发送一个POST请求与数据+操作（webix_operation =更新/删除/插入），所以我想我可以做这样的事情：

app.use(bodyParser.json()); app.use(bodyParser.urlencoded({ extended : true })); app.post("/Page2", function (req, res) { var operation = req.body.webix_operation; if (operation == 'update') { fs.readFile("JSON/DB.json", "utf8", function (err, data) { var allData = JSON.parse(data) var userData = { "id": req.body.id, "data1": req.body.data1, "data2": req.body.data2, "data3": req.body.data3, } allData.push(userData); var newData = JSON.stringify(allData); fs.writeFile("JSON/DB.json", newData, "utf8"); console.error(err.stack); }) res.send(); } else if (operation == 'insert') { } else if (operation == 'delete') { } else console.log("This operation is not supported") }); 

但它不起作用。

有人可以检查代码，也许搞清楚我做错了什么？

Answer 1

 app.post("/Page2", function (req, res, next) { var operation = req.body.webix_operation; if (['insert', 'update', 'delete'].indexOf(operation) == -1) return next(new Error('Bad request')); // More better use http post to insert, put to update, delete to delete // eg app.put('/page2', func) to update var userData = { id: req.body.id, data1: req.body.data1, data2: req.body.data2, data3: req.body.data3 } if (!userData.id) return next(new Error('id is not set')); fs.readFile("JSON/DB.json", "utf8", function (err, data) { if (err) return next(err); var allData; try { allData = JSON.parse(data); } catch(err) { return next(err); } // find index of element in allData var i = allData.reduce(function(iRes, e, iCurr) { return (e.id == userData.id) ? iCurr : iRes }, -1); if (i == -1 && (operation == 'update' || operation == 'delete')) return next(new Error(operation + ': Bad id')); if (operation == 'update') allData[i] = userData; if (operation == 'delete') allData.splice(i, 1); if (operation == 'insert') allData.push(userData); fs.writeFile("JSON/DB.json", JSON.stringify(allData), 'utf8', function (err) { if (err) return next(err); res.end(); }) }); // end of readFile }); ... app.use(function(err, req, res, next)) { console.log(req.url, err); res.end(err.message); }