发现我的问题

Question

我有多个项目，但无法通过其ID在每个项目页面中显示每个属性。（使用Nodejs，Reactjs，MongoDB ...）它给出了一个错误

在模型“项目”的路径“ _id”处，对值“：id”的对象ID广播失败

和此console.log：

console.log('-----------PROJECTS byId-----------', projects);

给我undefined

我的路线：

const express = require('express'),
Projects = require('../models/projects.js'),
app = express.Router();
exports.render_projects_byId = (req, res) => {
let id = req.params.id;

Projects.findById(id).exec((err, projects) => {
    if (err) {
        console.log(err);
    }
    console.log('-----------PROJECTS byId-----------', projects);
    res.json(projects)
  });
};

“我的项目”页面将通过其自己的ID出现项目属性

import React, { Component } from 'react';
import { NavLink } from 'react-router-dom';

import './Project.css';



class Project extends Component {
    state = {
     title : '',
     typeOfProduction: ''
    };

componentDidMount() {

    fetch('/dashboard/projects/:id')
    .then(response => { return response.json()
        .then(projects => {
            console.log(projects);
            this.setState({
                title: this.state.title,
                typeOfProduction: this.state.typeOfProduction
            })      
        })
    }).catch(error => console.error('Error:', error));
}

render() {
 console.log("This.state.projects " + this.state.projects);

    return (

        <div>
            <section className="Project container">
                  <h1>
                  {this.state.title} oi
                  </h1>
                  <h1>
                  {this.state.typeOfProduction} oi
                  </h1>
            </section>
        </div>
    );

    }
}

export default Project;

我的项目模型架构：

var mongoose = require("mongoose");

var projectSchema = new mongoose.Schema({

   title: String,
   typeOfProduction: String
})

module.exports = mongoose.model("Projects", projectSchema);

Answer 1

"CastError: Cast to ObjectId failed for value "{ id: ':id' }" at path "_id" for model "project"

您正在发送一个对象，但是它需要一个字符串。您应该尝试Projects.findById(id) ....

Answer 2

发现我的问题

我没有以正确的方式访问对象及其获取时的ID。

    console.log("PROPS " + JSON.stringify(this.props));

道具

{“ match”：{“ path”：“ / project /：id”，“ url”：“ / project / 5ba945d25589902362b54469”，“ isExact”：true，“ params”：{“ id”：“ 5ba945d25589902362b54469” }}，“ location”：{“ pathname”：“ / project / 5ba945d25589902362b54469”，“ search”：“”，“ hash”：“”}，“ history”：{“ length”：50，“ action”：“ PUSH“，” location“：{” pathname“：” / project / 5ba945d25589902362b54469“，” search“：”“，” hash“：”“}}}

然后我必须访问这样的对象参数：

 const { match: { params } } = this.props;

然后我知道我正在错误地路由项目：id

//之前

获取（/dashboard/project/:id）

//之后

获取（/dashboard/project/${params.id}）

class Project extends Component {
constructor(props){
    super(props);
    this.state = {
      project: {}
    };
}


componentDidMount() { 

console.log("PROPS " + JSON.stringify(this.props));

    const { match: { params } } = this.props;


    fetch(`/dashboard/project/${params.id}`)
    .then(response => {  return response.json()
    }).then(project => {
        this.setState({
            project: project
        })
    })
}

render() {

    return (

        <div>
            <section className="Project container">
                  <h1>
                  {this.state.project.title} oi
                  </h1>
                  <h1>
                  {this.state.project.typeOfProduction} oi
                  </h1>
            </section>
        </div>
    );

 }
}

export default Project;

按ID显示React属性

2 个答案:

发现我的问题