Node.js：未显示成功和错误消息

Question

我想在我的单个帖子上显示成功消息。我正在使用connect-flash，express-session显示Flash消息。

也试图在其他页面中刷新消息。但是，该消息不是强制性的。因此，它不会显示在任何页面上。我正在按scotch显示成功消息。

[当我尝试提交空白表格时，它在控制台MongoError: E11000 duplicate key error collection中显示以下错误

模式：

const eventSchema = new Schema({
    name: {
        type: String,
        require: [true, 'Event name is required']
    },
    slug: {
      type: String,
      unique: true,
      sparse: true
    },
    description: {
        type: String,
        require: [true, 'Event description is required']
    },
}, {collection: 'event'});

const eventModel = mongoose.model('Event', eventSchema);

app.js：

const session = require('express-session'),
    flash     = require('connect-flash');

app.use(session({
    secret: 'secret-key',
    cookie: {
        secure: true,
        maxAge: 60000,
    },
    resave: false,
    saveUninitialized: false
}));

app.use(flash());app.use(session({
    secret: 'secret-key',
    cookie: {
        secure: true,
        maxAge: 60000,
    },
    resave: false,
    saveUninitialized: false
}));
app.use(flash());

控制器：

const Event = require('../models/event'),
{ body, validationResult } = require('express-validator');

exports.showSingleEvent = async(req, res) => {
    try {
        await Event.findOne({ slug: req.params.slug }).exec((error, event) => {
            if(error) {
                res.status(404);
                res.send('Events not found');
            }

            res.render('pages/single', {
                title: `Event: ${event.name}`,
                event: event,
                success: req.flash('success')
            });
        });   
    } catch (error) {
        return next(error);
    }
};

exports.createEvent = ([
    // Validate data
    body('name')
        .isLength({ min: 5, max: 30 })
        .not().isEmpty()
        .trim()
        .escape(),
    body('description')
        .isLength({ min: 5, max: 200 }).withMessage('Must be between 5 & 200')
        .not().isEmpty()
        .trim()
        .escape()
], async(req, res) => {
    // Check if has errors
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        return res.status(422).json({ errors: errors.array() });
      } else {
        const event = new Event({
            name: req.body.name,
            description: req.body.description
        });

        await event.save((error) => {
            if(error) throw error;

            // Flash successful message
            req.flash('success', 'Data has created successfully!');

            // Redirect to newly created event
            res.redirect(`/events/${event.slug}`);
        });
    }
});

single.ejs：

<% if (success.length > 0) { %>
    <div class="alert alert-success mt-2 mb-2">
        <%= success %>
    </div>
<% } %>

<div class="jumbotron text-center">
    <h1><%= event.name %></h1>
    <p><%= event.description %></p>
    <p>
        <a href="/events" class="btn btn-success">All events</a>
    </p>
</div>

create.ejs：

       <% if (errors.length > 0) { %>
            <div class="alert alert-success mt-2 mb-2">
                <% for (error of errors ) { %>
                    <%= error %> <br>
                <% } %>
            </div>
        <% } %> 

        <form action="/events/create" method="POST">

            <div class="form-group">
                <label>Name</label>
                <input type="text" name="name" class="form-control">
            </div>

            <div class="form-group">
                <label>Description</label>
                <textarea name="description" rows="5" class="form-control"></textarea>
            </div>

            <div class="form-group">
                <button type="submit" class="btn btn-success btn-lg">Create</button>
            </div>

        </form>

Answer 1

此错误的原因是。您尝试在其中插入的集合中没有索引。因此，解决方案是删除该集合并再次运行您的程序。