Part1: FastAPI
Create virtualenv (optional)
Install FastAPI and all necessary things by-
pip install fastapi uvicorn websockets
Create main.py
file
from fastapi import FastAPI
app = FastAPI()
@app.get("/")
def root():
return {"msg":"welcome"}
and Run by -
uvicorn main:app --reload
Open this link in your browser http://127.0.0.1:8000
If you see something like this you are ready to go.
Now let's create websocket endpoint -
from fastapi import FastAPI, WebSocket
app = FastAPI()
# @app.get("/")
# def root():
# return {"msg":"welcome"}
@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
await websocket.accept()
while True:
data = await websocket.receive_text()
print(data)
await websocket.send_text(f"{data}")
This async
function will await until accept connection from frontend via await websocket.accept()
. And then when connection is created, our websocket will ready to communicate with frontend until connection closed.
data = await websocket.receive_text()
By this line of code we will receive data from frontend.
await websocket.send_text(f"{data}")
And by this line of code we are able to send data to frontend. And that's how we create two way communication.
Part2: Vue3 (Frontend)
let's create vue3 applicaion- Vue3 installation guide
npm init vue@latest
Delete all of the boilerplate code. And let's code in app.vue
file just for make things easier.
<script setup>
import { onMounted,ref } from 'vue'
const data = ref()
const inputData = ref()
const connection = new WebSocket("ws://localhost:8000/ws")
function submit() {
connection.send(inputData.value)
}
onMounted(() => {
connection.onmessage = function(e){
data.value = e.data
}
})
</script>
<template>
<h1>hello {{data}}</h1>
<input type="text" v-model="inputData" @keyup.enter="submit()">
<button @click="submit()">submit</button>
<RouterView />
</template>
Start building connection with fastAPI websocket by-
const connection = new WebSocket("ws://localhost:8000/ws")
In mounted hook we start listen what message is send by backend. Abd whatever data comes from backend we can store those data and can render it in tamplate by-
onMounted(() => {
connection.onmessage = function(e){
data.value = e.data
}
})
<!-- in template -->
<template>
<h1>hello {{data}}</h1>
</template>
Let's create a input field and send data from frontend and again receive those data in frontend via backend.
<template>
<h1>hello {{data}}</h1>
<input type="text" v-model="inputData" @keyup.enter="submit()">
<button @click="submit()">submit</button>
<RouterView />
</template>
And In submit()
function we will send data to the backend
function submit() {
connection.send(inputData.value)
}
Voila.... We are done 😎. Now you can do more experiment. Retrieve data from database and send it to frontend something like that. Or whatever you may wish.
Source Code: https://github.com/siumhossain/fastApi-Vue3-webSocket