expressjs-使用中间件功能

Question

I would like to know how I can move the following code into a separate function (in the same file) and call upon it when either I call the POST or PUT routes to add or update documents.

I'm using https://www.npmjs.org/package/express-validator

The following is currently in my POST route but when I'm updating a record the title will still need to be validated.

app.post('/docs', auth, function (req, res) {
  req.checkBody('title', 'Title is required').notEmpty();
  var errors = req.validationErrors();

  if(errors){
    res.json(400, { errors: errors });
    return;
  }

  //go ahead and save the document

});

I've tried making my own function but I'm not sure where to put the var errors = req.validationErrors(); or whether it's bad practice to return 400 errors from a separate function.

Any help/code much appreciated.

Answer 1

The body of the middleware function is almost identical to the code you are using right now, only with two notable differences:

• The function ensures that the req.method is either POST or PUT.
• The next() function is called when validation passes. This will trigger the next middleware function in the chain, or the route handler.

app.use('/docs', function(req, res, next) {
  if (req.method == 'POST' || req.method == 'PUT') {
    req.checkBody('title', 'Title is required').notEmpty();
    var errors = req.validationErrors();
    if (errors) {
      res.json(400, { errors: errors });
      return;
    }
  }
  next();
});

app.post('/docs', auth, function (req, res) {
  // go ahead and save the document
});