Handlebars：访问已被拒绝解析属性“_id”，因为它不是其父级的“自己的属性”

Posted 2023-03-10

【中文标题】Handlebars：访问已被拒绝解析属性“_id”，因为它不是其父级的“自己的属性”

【英文标题】：Handlebars: Access has been denied to resolve the property "_id" because it is not an "own property" of its parent

【发布时间】：2021-05-09 02:22:36

【问题描述】：

我是 JS 和 Handlebars 的新手，非常感谢我正在从事的项目的一些帮助。我正在使用 AJAX 创建一个新类别，然后尝试从服务器获取该类别（当前，如果我刷新，新类别将消失。我了解 AJAX 是异步的，并试图从服务器（如果可能）。目前，我收到以下错误：

。

从我所做的阅读来看，我相信这是因为 Handlebars 4.6.0 和 on 默认情况下禁止访问上下文对象的原型属性和方法。为了解决这个问题，我安装了@handlebars/allow-prototype-access 包，但我不确定如何在我的 app.engine 中使用它。有人可以帮忙吗？这是我的 app.js：

const globalVariables = require('./config/configuration')

const express = require('express');
const mongoose = require('mongoose');
const path = require('path');
const hbs = require('express-handlebars');
const mongoDbUrl, PORT = require('./config/configuration');
const flash = require('connect-flash');
const session = require('express-session');
const selectOption = require('./config/customFunctions');
const fileUpload = require('express-fileUpload');
const methodOverride = require('method-override');
const allowInsecurePrototypeAccess = require('@handlebars/allow-prototype-access');

const app = express();

/* Configure Mongoose to Connect MongoDB */
mongoose.connect(mongoDbUrl,  useNewUrlParser: true )
    .then(response => 
        console.log("MongoDB Connected Successfully.",  useNewUrlParser: true );
    ) .catch(err => 
        console.log("Database connection failed", err)
    );



/* Configure express*/
app.use(express.json());
app.use(express.urlencoded(extended: true))
app.use(express.static(path.join(__dirname, 'public')));

/*flash and session*/
app.use(session(
    secret: 'anysecret',
    saveUninitialized: true,
    resave: true
))

app.use(flash());

app.use(globalVariables);

app.use(fileUpload(
    limits:  fileSize: 50 * 1024 * 1024 ,
  ));

/* Setup View Engine To Use Handlebars */
app.engine('handlebars', hbs(defaultLayout: 'default', helpers: select: selectOption));
app.set('view engine', 'handlebars');

/* Method Override Middleware */
app.use(methodOverride('newMethod'));


/* Routes */
const defaultRoutes = require('./routes/defaultRoutes');
const adminRoutes = require('./routes/adminRoutes');

app.use('/', defaultRoutes);
app.use('/admin', adminRoutes);

app.listen(PORT, () => 
    console.log(`Server is running on port 3000`);
)

这是我用来创建类别的 .handlebars 表单：

 $("#create-category-button").on('click', function (e) 
            e.preventDefault();

            var data = $("#category-title").val();

            $.ajax(
                url: '/admin/category',
                type: 'POST',
                data: name: data,
                success: function (response) 

                    var html = `<tr>
                        <td>$response.title</td>
                        <td class="d-flex justify-content-center">
                            <a href="/admin/category/edit/$response._id" class="btn btn-sm btn-warning mr-2">Edit</a>
                            <form action="/admin/category/$response._id?newMethod=DELETE" method="post">
                                <button class="btn btn-sm btn-danger" type="submit">Delete</button>
                            </form>
                        </td>
                    </tr>`;

                        console.log(response);
                    $(".category-list").append(html);

                
            );

            $("#category-title").val('');
        );

非常感谢您的帮助！

【参考方案1】：

知道了！我不得不调整我的 app.engine 如下：

app.engine('handlebars', hbs( defaultLayout: 'default', helpers: select: selectOption, handlebars: allowInsecurePrototypeAccess(_handlebars)));

【参考方案2】：

我所做的是重写对象。就我而言：

router.post('/getMessage', async (req, res) => 

    const dbMessageData = await Message.findByPk(req.body.message_id,);
    console.log("---> dbMessageData :" + JSON.stringify(dbMessageData));
    const  message  = 
        "id": dbMessageData.id,
        "title": dbMessageData.title,
        "content": dbMessageData.content,
        "user_id": dbMessageData.user_id,
        "UserId": dbMessageData.user_id
    
         console.log("---> message :" + JSON.stringify (message) );
    res.render('updateMessage', message, session: req.session);

);

通过这种方式，您不必为不必要的配置问题而烦恼。