This content originally appeared on DEV Community and was authored by Kumar Kalyan
Getting started
In this article you will learn how to build a simple todo API using Nodejs. Nodejs is an open-source , JavaScript runtime environment use foe backend development. It's is used by the tech giants all over the world having wonderful community support and well structured documentation.
Install the dependencies
Before you satrt building the API you must install the following dependencies mentioned below.
- nodejs
- expressjs
- mongoosejs
- Mongodb
- Postman
-
clone this repo
After you clone the github repo open the folder named
hc-api-eventin the terminal and hitnpm install, this will install all the required packages mentioned in thepackage.jsonfile.
The File structure
Import the modules
To start using the libraries we need to import them first
/*Importing the moudule*/
const express = require('express');
const mongoose = require('mongoose');
const app = express()
app.use(express.json())
require('dotenv').config();
Connect the database and start the API
As we are building a todo API so we need to store the data todo's and there it comes the need of database.Database is an organized way to store collection of data just like taking down notes in a notebook.We are using Mongodb which is a popular nosql database.So to store the todo's into the database first we need to connect our API with Mongodb. We will use the mongoose instance which is having a connectfuntion which takes two parameters one is the connection string which is necessary and other is options . Use the below piece of code to connect the database with the API
const start = () => {
mongoose.connect(process.env.MONGODB_CONNECTION_STRING, {
useNewUrlParser: true,
useUnifiedTopology: true
}).then(
app.listen(5000, () => {
console.log("App is listining ");
})
).catch((err) => {
console.log("Error ")
})
}
start()
mongoose.connect() returns a promise which we are handling using then() and catch(). Here we are declaring that if the db connection is successfull then only start the API else catch the eror and stop the API. Now use our API we need to have some ednpoint so we are creating an HTTP server which will listen to port=5000, this is just like watching your favourite show on a particular channel out of many.
Designing the schema and creting the Model
Schemas are like skeleteal structures of data, It contains the necessary metadata of the data we are passing into the database. Suppose our data is related to a person so there will be a property named say name of type string which is required or say a property named isEmployed of type boolean and defalut value will be false
person schema :{
isEmployed : { type: Boolean, default: false },
Name: {type: String, required: true}
}
Model on the other hand provides an interface to the database for creating, querying, updating, deleting records, etc.
// Mongodb Schema & Model
const todoSchema = mongoose.Schema({
todo: String
})
const Todo = mongoose.model('Todo', todoSchema)
Designing the API request
Let me tell you that the behavior of an API is to accept a request and then pass a desired response. The request contains are metadata about what we want, in which form we are requesting the data, from which browser, which IP and a lot more similarly a response all the metadata taht we are passing to the Cient. In CRUD architechture we deal with 4 types of requests get Reading , post for Creating , put for updating and delete for deleting.So,Now we have created a model named Todo and we can use it to interact with our db.
Get All Todo's
We will just grab all the todo's using find() and pass it as a response
app.get('/', async (req, res) => {
const data = await Todo.find();
res.json(data)
})
Create a Todo
We will use the create() and will store the todo in the db
app.post('/', async (req, res) => {
const data = await Todo.create(req.body);
res.send(data)
})
Working with a particular document
Every doccument Mongodb creates it generated an ID. ID's are necessary to filter documents having similar property, just like there can be two employees with same name and same height but will have different employee ID's. Just like that every documnet we create mongobd automatically generates an Unique ID for it . Now we will be using these id in our request to filter data
Get a single Todo
As I have stated that our request contains all the metadata so we will be grabing the id of a todo from the request params and will us to filter that particular todo from our db using the findById
app.get('/:id', async (req, res) => {
const data = await Todo.findById(req.params.id);
res.json(data)
})
Update a Todo
We will use a method named findByIdAndUpdate and there will pass the id of the todo we want to delete followed by req.body with conataines the updated todo and lastly we will pass a option new which will be set to true
app.put('/:id', async (req, res) => {
const data = await Todo.findByIdAndUpdate(req.params.id, req.body, { new: true })
res.send(data)
})
Delete a Todo
Finally we will use the same approach to delete a todo using a method named findByIdAndUpdate and will pass the todo idand our todo will be deleted.
app.delete("/:id", async (req, res) => {
const data = await Todo.findByIdAndDelete(req.params.id)
res.send("Todo deleted")
})
The Final code
/*Importing the moudule*/
const express = require('express');
const mongoose = require('mongoose');
const app = express()
app.use(express.json())
require('dotenv').config();
// Mongodb Schema & Model
const todoSchema = mongoose.Schema({
todo: String
})
const Todo = mongoose.model('Todo', todoSchema)
//api requests
app.get('/', async (req, res) => {
const data = await Todo.find();
res.json(data)
})
app.post('/', async (req, res) => {
const data = await Todo.create(req.body);
res.send(data)
})
app.get('/:id', async (req, res) => {
const data = await Todo.findById(req.params.id);
res.json(data)
})
app.put('/:id', async (req, res) => {
const data = await Todo.findByIdAndUpdate(req.params.id, req.body, { new: true })
res.send(data)
})
app.delete("/:id", async (req, res) => {
const data = await Todo.findByIdAndDelete(req.params.id)
res.send("Todo deleted")
})
const start = () => {
mongoose.connect(process.env.MONGODB_CONNECTION_STRING, {
useNewUrlParser: true,
useUnifiedTopology: true
}).then(
app.listen(5000, () => {
console.log("App is listining ");
})
).catch((err) => {
console.log("Error ")
})
}
Key Take aways
- Request & Response
- CRUD Architechture
- Mongoose model, Schema & simple data filtering
Conclusion
Do share this article with your friends and peers if you find it useful and make sure to hit a reaction as it helps my page grow. Feel free to ask any questions in the comments
Connect
This content originally appeared on DEV Community and was authored by Kumar Kalyan
Kumar Kalyan | Sciencx (2022-06-24T16:22:02+00:00) Simple todo API with complex concepts. Retrieved from https://www.scien.cx/2022/06/24/simple-todo-api-with-complex-concepts/
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