javascript - 如何使用node.js在server.js中传递参数

Question

我想将参数数据从mongoDB传递到服务器端。 我创建了全局变量diagramData以从diagramModel.find()查询传递到app.post函数。但当 console.log(diagramData) 时它是空数组。有人能帮我弄清楚吗？谢谢

var diagramData = [];
mongoose.connection.on('connected', function () {
    diagramModel.find({}, function(err, data) {
      diagramData = data;
    });
});

app.post('/display_bpmnFile', function(req, res) {
    console.log(diagramData);
    res.send({
        file: diagramData
    });
});

Answer 1

You will not get value in that since when you call your route then it works as async nature so most of the chance your array will be empty.

<小时/>

It's not a proper answer since I am writing your connection in route.

在某个地方写下你的连接并在任何地方使用它

app.post('/display_bpmnFile', function(req, res) {
  mongoose.connection.on('connected', function() {//connection code must not be here put it in somewhere else and make it common
    diagramModel.find({}, function(err, data) {
      if (!err) {
        res.send({
          file: data
        });
      }
    });
  });
});