Expressjs基于参数检索集合

Question

我试图根据视图中的一个模式属性的参数请求来循环我的数据库集合。我的模式中有一个tags属性，保存为数组。我希望能够做的是点击保存到该数组的值中的一个值，该值将呈现包含所选标签值的集合的页面。我已经能够创建路线，该路线将指引我点击的单个标签，但是我收到tags: [xxx, xxx, xxx] has no method .forEach。当我在我的视图中呼叫我的循环时会发生这种情况。为什么会这样，我该如何解决这个问题？

错误消息：

TypeError: /Users/user/Desktop/Projects/node/blog/views/pages/tag.ejs:15 
    13| <div class="col-md-12"> 
    14| <h1><%= blogpost.tags %></h1> 
>> 15| <% blogpost.forEach(function(blogpost) { %> 
    16| <%= blogpost.title %> 
    17| <% }); %> 
    18| </div> 

Object { _id: 54c7bd20c58f389232000001, 
category: 'Analytics/SEO/SEM', 
content: '', 
tagline: 'yep', 
author: 'Author', 
blogUrl: 'roger', 
featureImage: '/images/event-placeholder.png', 
title: 'Roger', 
__v: 0, 
date: Tue Jan 27 2015 11:29:48 GMT-0500 (EST), 
tags: [ 'wolf', ' cow', ' monkey' ] } has no method 'forEach' 

这里是我的模型：

var mongoose = require('mongoose'); 
var mongoosePaginate = require('mongoose-paginate'); 
var Schema  = mongoose.Schema; 



var BlogPostSchema = new Schema({ 
     title: { type: String, unique: true }, 
     featureImage: String, 
     blogUrl: String, 
     author: String, 
     tagline: String, 
     category: String, 
     content: String, 
     tags: { type: Array, lowercase: true }, 
     date: { type: Date, default: Date.now() } 
}); 

BlogPostSchema.post('init', function (post) { 
    var date = new Date(post.date || Date.now()); 
    post.dateString = date.getMonth() + 1 + '/' + date.getDate() + '/' + date.getFullYear(); 

}); 

BlogPostSchema.plugin(mongoosePaginate); 

var Blogpost = mongoose.model("Blogpost", BlogPostSchema); 



module.exports = mongoose.model('Blogpost', BlogPostSchema); 

这里是我如何我的路线内叫我单独选择标签（难道我的函数使用正确的参数调用方法？）：

router.route('/admin/posts/create') 

    // START POST method 
     .post(function(req, res) { 

      console.log("New instance"); 
      console.log(req.body.tags); 

      var blogpost = new Blogpost(); // create a new instance of a Blogpost model 

      blogpost.title = req.body.title; // set the blog title 
      blogpost.featureImage = req.body.featureImage; // set the blog image 
      blogpost.blogUrl = blogpost.title.toLowerCase().replace(/\s+/g,"-"); 
      blogpost.author = req.body.author; // set the author name 
      blogpost.tagline = req.body.tagline; // set the tagline 
      blogpost.content = req.body.content; // set the blog content 
      blogpost.category = req.body.category; // set the category 
      blogpost.tags = req.body.tags.trim().split(","); // set the tags 
       //Save Blog Post 
       blogpost.save(function(err) { 
        if (err) 
         res.send(err); 

        res.redirect(303, '/'); //NEEDS TO BE CHANGED 
       }); 

     }) // END POST method 


     .get(isLoggedIn, function(req, res, blogpost) { 
      res.render('pages/blogpost-create', { 
       blogpost : blogpost 
      }); 
     }); 

function getTagCriteria(params){ 
    return { 
    tags: params.blogpost_tags 
    }; 
} 

router.route('/tag/:blogpost_tags') 

    .get(function (req, res) { 
     var tagCriteria = getTagCriteria(req.params); 
     Blogpost.findOne(tagCriteria, function (err, blogpost) { 
     if (err) 
      res.sent(err); 
     res.render('pages/tag', { 
      blogpost : blogpost 
     }) 
     }) 
    }); 

页/标签视图文件：

<div class="container"> 
     <div class="col-md-12"> 
      <h1><%= blogpost.tags %></h1> 
      <% blogpost.forEach(function(blogpost) { %> 
       <%= blogpost.title %> 
      <% }); %> 
     </div> 
    </div> 

Answer 1

您蒙戈查询更改为：

Blogpost.find(tagCriteria, function (err, blogpost) { 
    if (err) 
     res.sent(err); 
    res.render('pages/tag', { 
     blogpost : blogpost 
    }) 
    }) 

注：博文现在是[]数组，而不是一个对象{}

然后在你的玉器，请执行下列操作

<% blogpost.forEach(function(post) { %> 
    <%= post.title %> 
<% }); %>