Create a URL shortener app in Vue JS, Python, Mongo DB

by Posted on

In this tutorial, we will create a URL shortener app in Vue JS, Python and Mongo DB. We will use Vue JS as frontend, Python as backend and Mongo DB as database.

We will be creating a single page application in Vue JS 3, FastAPI for creating APIs in Python and standard Mongo DB for storing data.

User will enter a URL and the app will create a shorter URL of it. User can share that short URL on social media. Whenever someone access that short URL, we will show ads to him for 5 seconds. Then he will be able to move to the actual URL.

User can see how many people have clicked on his shorten URL and how many have accessed the real URL.

We will create the frontend in Vue JS 3, it will be a single page application (SPA). The backend will be in Python, we will be using FastAPI.

Add URL – Vue JS

The first step is to show user a form where he can enter his URL to shorten. So go ahead and create a folder anywhere in your computer (I have created on desktop). And inside that folder, create 2 more folders named “web” and “api”.

All our frontend code will go in “web” and all our backend code will go in “api”. Now open your command prompt (CMD) or terminal in your “web” folder and run the following command to install Vue JS.

> npm install -g @vue/cli

Then we will create an SPA in that folder.

> vue create .

If asked for Vue JS version, select Vue JS 3. Then run the following command to start Vue JS on localhost.

> npm run serve

You can access your app from http://localhost:8080/

Now go in your “web/src/components” and delete the “HelloWorld.vue” file. And create a file named “HomeComponent.vue”. Following will be the content of that file:

<template>
	HomeComponent
</template>

<script>
	export default {
		name: "HomeComponent"
	}
</script>

Open “src/main.js” and remove the “HelloWorld” component occurrences from there too.

In your components folder, create a folder named “layouts” and create 2 files in it: “AppHeader.vue” and “AppFooter.vue”. Following will be the content of these files:

// AppHeader.vue

<template>
	AppHeader
</template>

<script>
	export default {
		name: "AppHeader"
	}
</script>

// AppFooter.vue
<template>
	AppFooter
</template>

<script>
	export default {
		name: "AppFooter"
	}
</script>

Then run the following command to install “vue-router” that will be used for navigation, “sweetalert2” for displaying popups and “axios” for making AJAX calls.

npm install vue-router sweetalert2 axios

Then in your “main.js”, initialize the vue-router module.

import { createRouter, createWebHistory } from "vue-router"
import HomeComponent from "./components/HomeComponent.vue"

const app = createApp(App)

const routes = [
	{ path: "/", component: HomeComponent }
]

const router = createRouter({
	history: createWebHistory(),
	routes
})

app.use(router)
app.mount('#app')

Open your “web/src/App.vue” and replace the existing content with the following.

<template>
  <app-header />
    <router-view />
  <app-footer />
</template>

<script>

import AppHeader from "./components/layouts/AppHeader.vue"
import AppFooter from "./components/layouts/AppFooter.vue"

export default {
  name: 'App',
  components: {
    AppHeader,
    AppFooter
  }
}
</script>

After that, download Bootstrap 5 and paste the CSS and JS files in your “web/src/assets” folder. Then include them in your AppHeader component.

import "../../assets/css/bootstrap.css"
import "../../assets/js/jquery.js"
import "../../assets/js/bootstrap.js"

If you get any error regarding popper, just run the following commands.

> npm install @popperjs/core
> npm remove @vue/cli-plugin-eslint

Learn more about them in here.

Then open your HomeComponent and create a form inside <template> tag. The form simply have 1 field to enter the URL and a submit button.

<div class="container">
	<div class="row">
		<div class="offset-md-3 col-md-6">
			<form v-on:submit.prevent="shorten_url">
				<div class="form-group">
					<label class="form-label">Enter URL</label>
					<input type="url" name="url" placeholder="Enter URL" class="form-control" required />
				</div>

				<input type="submit" class="btn btn-primary" style="margin-top: 10px;" value="Shorten" />
			</form>

			<!-- [table goes here] -->
		</div>
	</div>
</div>

Then create a function “shorten_url” in your <script> tag in HomeComponent.

import axios from "axios"
import swal from "sweetalert2"

export default {
	name: "HomeComponent",

	methods: {
		async shorten_url() {
			const form = event.target
			const formData = new FormData(form)
			formData.append("timezone", Intl.DateTimeFormat().resolvedOptions().timeZone)

			try {
				const response = await axios.post(
					this.$api_url + "/shorten-url",
					formData
				)

				if (response.data.status == "success") {
					// [on url shortened success]
				} else {
					swal.fire("Error", response.data.message, "error")
				}
			} catch (exp) {
				console.log(exp)
			}
		}
	}
}

In your “main.js” add the following line that defines the URL of our Python API.

app.config.globalProperties.$api_url = "http://127.0.0.1:8000"

In the above function, we are sending form data to the server. We are also sending current timezone, so the server can return the time (in local timezone) when the URL was added.

Add URL – Python, Mongo DB

So the view is created, now we need to create our backend API that will handle this request.

Making sure you have installed Python 3 in your system, run the following commands in your “api” folder.

pip3 install fastapi uvicorn pymongo python-multipart

Create a file named api.py and write the following code in it:

import random, string
from fastapi import FastAPI, Form
from typing_extensions import Annotated
from fastapi.middleware.cors import CORSMiddleware
from pymongo import MongoClient
from bson.objectid import ObjectId
from datetime import datetime, timezone as timezone_module
from dateutil import tz

MONGO_CONNECTING_STRING = "mongodb://localhost:27017"
client = MongoClient(MONGO_CONNECTING_STRING)
db_name = "url_shortener"
db = client[db_name]

app = FastAPI()

app.add_middleware(
	CORSMiddleware,
	allow_origins=["*"]
)

@app.post("/shorten-url")
def shorten_url(url: Annotated[str, Form()], timezone: Annotated[str, Form()]):

	while True:
		random_characters = "".join(random.choice(string.ascii_lowercase) for _ in range(8))
		url_obj = db["urls"].find_one({
			"hash": random_characters
		})

		if (url_obj == None):
			break

	inserted_doc = {
		"_id": ObjectId(),
		"url": url,
		"hash": random_characters,
		"views": 0,
		"clicks": 0,
		"created_at": datetime.now(timezone_module.utc)
	}

	db["urls"].insert_one(inserted_doc)
	inserted_doc["_id"] = str(inserted_doc["_id"])
	inserted_doc["created_at"] = convert_utc_to_local(timezone, inserted_doc["created_at"])

	return {
		"status": "success",
		"message": "URL has been shortened.",
		"url": inserted_doc
	}

def convert_utc_to_local(timezone, utc):
	# Hardcode zones:
	from_zone = tz.gettz('UTC')
	to_zone = tz.gettz(timezone)

	# Tell the datetime object that it's in UTC time zone since 
	# datetime objects are 'naive' by default
	utc = utc.replace(tzinfo=from_zone)

	# Convert time zone
	utc = utc.astimezone(to_zone).strftime("%b %d, %Y %H:%M:%S")

	return utc

To start the API, run the following command in your “api” folder:

uvicorn api:app --reload

You can access it from here:

http://127.0.0.1:8000

You might see it blank and that’s okay. Because it will be accessed via AJAX calls.

Explanation:

First, we are making connection with Mongo DB. Then we are initializing FastAPI and setting CORS middleware to prevent CORS error.

After that, we are creating a function that will handle the request. It accepts URL and timezone.

It will generate random 8 characters and make sure they are unique in database using do-while loop.

Then it will insert the record in database. And in order to return the inserted document to the client side, we need to convert the ObjectId to string.

Date & time will be stored in UTC in database. But to return to client side, we have to convert UTC to user’s local timezone. So we have created a separate function “convert_utc_to_local” for that.

Show all added URLs – Vue JS

In your HomeComponent, write the following code in [table goes here] section.

<table class="table table-bordered" style="margin-top: 50px;">
	<thead>
		<tr>
			<th>URL</th>
			<th>Views</th>
			<th>Clicks</th>
			<th>Created at</th>
		</tr>
	</thead>

	<tbody>
		<tr v-for="(url, index) in urls">
			<td>
				<router-link v-bind:to="'/url/' + url.hash" v-text="url.hash"></router-link>
			</td>
			<td v-text="url.views"></td>
			<td v-text="url.clicks"></td>
			<td v-text="url.created_at"></td>
		</tr>
	</tbody>
</table>

Then in your <script> tag, initialize an empty array.

data() {
	return {
		urls: []
	}
},

And write the following code at [on url shortened success] section:

this.urls.unshift(response.data.url)

Add a “mounted” event in your Vue JS object.

mounted() {
	this.get_data()
}

After that, create the following method inside your “methods” object.

async get_data() {
	const formData = new FormData()
	formData.append("timezone", Intl.DateTimeFormat().resolvedOptions().timeZone)

	try {
		const response = await axios.post(
			this.$api_url + "/fetch-urls",
			formData
		)

		if (response.data.status == "success") {
			this.urls = response.data.urls
		} else {
			swal.fire("Error", response.data.message, "error")
		}
	} catch (exp) {
		console.log(exp)
	}
}

Fetch all URLs – Python, Mongo DB

Now we need to create an API in Python that will fetch all URLs from Mongo DB. Write the following code in your “api/api.py” file.

@app.post("/fetch-urls")
def fetch_urls(timezone: Annotated[str, Form()]):
	urls = db["urls"].find().sort("created_at", -1)

	url_arr = []
	for url in urls:
		url["_id"] = str(url["_id"])
		url["created_at"] = convert_utc_to_local(timezone, url["created_at"])

		url_arr.append(url)

	return {
		"status": "success",
		"message": "Data has been fetched.",
		"urls": url_arr
	}

Test the app now and you will see all your added URLs. Now whenever a URL is clicked, we will show a new page where user will have to wait for 5 seconds to access the real URL.

Access the URL – Vue JS

In your “web/src/components” folder, create a file named “URLComponent.vue” and write the following code in it:

<template>
	URLComponent
</template>

<script>

	export default {
		name: "URLComponent"
	}
</script>

Register it in your “main.js” file.

import URLComponent from "./components/URLComponent.vue"

And add it in “routes” array too.

{ path: "/url/:url", component: URLComponent }

Back to your URLComponent, write the following code inside <template> tag.

<div class="container">
	<div class="row">
		<div class="col-md-12">
			<div class="float-end" style="padding: 15px;
			    border-radius: 5px;
			    background-color: lightblue;
			    cursor: pointer;">
			    <span v-if="remaining_seconds > 0">
			    	Redirecting in <span v-text="remaining_seconds"></span> seconds
			    </span>
				
			    <span v-else v-on:click="goto_website">Go to website</span>
			</div>
		</div>
	</div>
</div>

This will show a text that will show the number of seconds remaining till user has to wait. When the time is over, it will show a clickable text which when clicked, should move the user to the actual URL.

import axios from "axios"
import swal from "sweetalert2"

export default {
	name: "URLComponent",

	data() {
		return {
			url: this.$route.params.url,
			remaining_seconds: 5,
			url_obj: null,
			interval: null
		}
	},

	methods: {
		async goto_website() {
			if (this.url_obj == null) {
				return
			}

			window.location.href = this.url_obj.url
		},

		async get_data() {
			const formData = new FormData()
			formData.append("url", this.url)

			try {
				const response = await axios.post(
					this.$api_url + "/get-url",
					formData
				)

				if (response.data.status == "success") {
					this.url_obj = response.data.url
				} else {
					swal.fire("Error", response.data.message, "error")
				}
			} catch (exp) {
				console.log(exp)
			}
		}
	},

	mounted() {
		const self = this
		this.get_data()

		setTimeout(function () {
			self.interval = setInterval(function () {
				self.remaining_seconds--

				if (self.remaining_seconds <= 0) {
					clearInterval(self.interval)
				}
			}, 1000)
		}, 500)
	}
}

When this component is mounted, we will call “get_data” function that will fetch the single URL data from Python API.

Also, it will start a countdown timer from 5. Once timer hits 0, you can click the button and go to your actual URL.

Fetch single URL – Python, Mongo DB

Create the following API in your “api/api.py” file.

@app.post("/get-url")
def get_url(url: Annotated[str, Form()]):

	url = db["urls"].find_one({
		"hash": url
	})

	if (url == None):
		return {
			"status": "error",
			"message": "URL not found."
		}

	url["_id"] = str(url["_id"])

	return {
		"status": "success",
		"message": "Data has been fetched.",
		"url": url
	}

This will fetch the single URL from Python API.

Number of clicks on Shorten URL

When you share the shorten URL with your friends, you might want to know how many have clicked the shorten URL and how many clicked the actual URL.

To increment number of clicks on shorten URL, we will simply go to “api.py” function “get_url” and add the following code before converting ObjectId “_id” to string.

db["urls"].find_one_and_update({
	"_id": url["_id"]
}, {
	"$inc": {
		"views": 1
	}
})

Test now and you will see whenever someone access your shorten URL page, your “views” gets incremented in HomeComponent.

Number of clicks on actual URL

In order to see how many has clicked on your actual URL, you need to open your “URLComponent.vue” file. Add the following lines in your “goto_website” function before the “window.location.href” line.

const formData = new FormData()
formData.append("url", this.url)
window.navigator.sendBeacon((this.$api_url + "/url-clicked"), formData)

Then create its API in Python that will handle this request.

@app.post("/url-clicked")
def url_clicked(url: Annotated[str, Form()]):
	db["urls"].find_one_and_update({
		"hash": url
	}, {
		"$inc": {
			"clicks": 1
		}
	})

Now whenever someone visit the actual URL, the “clicks” counter gets incremented.

Header and Footer

Write the following code insde <template> tag of your AppHeader component.

<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <div class="container-fluid">
    <router-link class="navbar-brand" to="/">URL Shortener</router-link>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
      <ul class="navbar-nav me-auto mb-2 mb-lg-0">
        <li class="nav-item">
          <router-link class="nav-link active" aria-current="page" to="/">Home</router-link>
        </li>
      </ul>
    </div>
  </div>
</nav>

And change your AppFooter component to the following.

<template>
	<footer class="container-fluid" style="margin-top: 50px; background-color: #e9e9e9; padding: 25px;">
		<p class="text-center" style="margin-bottom: 0px;">
			&copy;<span v-text="year"></span>&nbsp;
			adnan-tech.com
		</p>
	</footer>
</template>

<script>
	export default {
		name: "AppFooter",

		data() {
			return {
				year: new Date().getFullYear()
			}
		}
	}
</script>

So this is how you can create a URL shortener app using Vue JS as frontend, Python as backend and Mongo DB as database. If you face any problem in following this, kindly do let me know.

Post Views: 109

Published by adnanafzal565