javascript - 为什么我没有在UI中收到验证Flash消息，却出现Flash错误，例如[对象对象]，[对象对象]，[对象对象]

我正在开发NodeJs应用程序，它是Blog应用程序。并且我使用了Express Validator，在UI端使用Express Flash消息将数据库中的帖子保存到数据库之前，我试图使用Flash消息来验证Data，我成功将数据保存在数据库中，但是提交表单后消息未出现在UI端，我得到了Flash错误[object Object],[object Object],[object Object]

我正在使用哈巴狗模板引擎。

app.js

const express = require("express");
const path = require("path");
const app = express();
const mongoose = require("mongoose");
const Article = require("./models/article");
const bodyParser = require("body-parser");
const { check, validationResult } = require("express-validator");
const flash = require("connect-flash");
const session = require("express-session");

//Express Session Middleware
app.use(
  session({
    secret: "keyboard cat",
    resave: true,
    saveUninitialized: true
  })
);
app.use(flash());

app.use((req, res, next) => {
  res.locals.errors = req.flash("error");
  res.locals.successes = req.flash("success");
  next();
});
app.get("/articles/add", (req, res) => {
  res.render("add_articles", {
    title: "Add Articles"
  });
});

// Add Submit POST Route
app.post(
  "/articles/add",
  [
    check("title", "Title is required")
      .not()
      .isEmpty(),
    check("author", "Author is required")
      .not()
      .isEmpty(),
    check("body", "Body is required")
      .not()
      .isEmpty()
  ],
  (req, res) => {
    const errors = validationResult(req);

     if (errors) {
      res.render("add_articles", {
        title: "Add Articles",
        errors: errors
      });
    } else {
      //GetErrors
      let article = new Article();
      article.title = req.body.title;
      article.author = req.body.author;
      article.body = req.body.body;

      article.save(err => {
        if (err) {
          console.log(err);
          return;
        } else {
          req.flash("success", "Article Added");
          res.redirect("/");
        }
      });
    }
  }
);

message.pug

.messages
 each type in Object.keys(messages)
    each message in messages[type]
      div(class="alert alert-"+type) #{message}

layout.pug

 .container
      if successes
        for success in successes
           div.alert.alert-success #{ success }
      if errors
        for error , i in errors
           div.alert.alert-danger #{ error }

任何帮助都受到高度赞赏。

最佳答案

1）我要注意的第一件事是有关检查是否存在任何验证错误的方式：

const errors = validationResult(req); if (errors) {...}

应替换为：

const errors = validationResult(req); if (errors.isEmpty()) {...}

2）还有另一个问题，与获取错误数组有关。
代替：

res.render("add_articles", { title: "Add Articles", errors: errors});

您需要使用：

res.render("add_articles", { title: "Add Articles", errors: errors.array()});

资料来源：Express validator docs