[!SUMMARY]- Table of Contents - [[Axios#Installation|Installation]] - [[Axios#Basic Code|Basic Code]] - [[Axios#Set default URL|Set default URL]] - [[Axios#Set protected call function|Set protected call function]]

Installation¶

npm install axios

Basic Code¶

const getUser = async () => {
  try {
    const response = await axios.get('/user?ID=12345');
    console.log(response);
  } catch (error) {
    console.error(error);
  }
}

Set default URL¶

In the starting file of react application write the following

if (import.meta.env.DEV) { //for vite application
    console.log("Running in development mode");
    axios.defaults.baseURL = import.meta.env.VITE_LOCALHOST;
} else {
    console.log("Running in production mode");
    axios.defaults.baseURL = import.meta.env.VITE_SERVER_URL;
}

Reference Link -> Vitejs.dev

You do not require to create .Dev environment variables in .env, it is default for vite application For other react application you can use following :

if (process.env.NODE_ENV === "development") {
    console.log("Running in development mode");
    axios.defaults.baseURL = process.env.REACT_APP_LOCALHOST;
} else {
    console.log("Running in production mode");
    axios.defaults.baseURL = process.env.REACT_APP_SERVER_URL;
}

Set protected call function¶

Method 1 - When backend returns a message¶

import axios from "axios";
import Cookies from "js-cookie";

async function ApiCall(url, httpMethod, data) {
    const token = Cookies.get("studentsToken") || Cookies.get("professorsToken");
    try {
        const config = {
            headers: {
                Authorization: `Bearer ${token}`,
            },
        };
        if (httpMethod === "GET") {
            const response = await axios.get(url, config);
            if (response.data.message === "Invalid token" || response.data.message === "No Token Provided") {
                // remove Cookies if used
                window.location.href = "/";
            }
            return response;
        } else if (httpMethod === "POST") {
            const response = await axios.post(url, data, config);
            if (response.data.message === "Invalid token" || response.data.message === "No Token Provided") {
                // remove Cookies if used
                window.location.href = "/";
            }
            return response;
        }
    } catch (error) {
        console.error("Error in API call:", error);
        throw error;
    }
}

export default ApiCall;

Method 2 - When Backend return status code¶

import { toast } from "react-toastify";
import axios from "axios";

const ApiCall = async (url, method, navigate, data) => {
  console.log("******** Inside ApiCall function ********");

  if (method === "GET") {
    try {
      const response = await axios.get(url);
      console.log(response.data);
      return response.data;
    } catch (error) {
      console.error("Error in API call:", error);
      if (error.response.status === 401) {
        toast.error("You are not authorized to access this page. Please login first.");
        navigate("/login");
      } else if (error.response.status === 404) {
        toast.error("The requested resource was not found.");
        navigate("/");
      } else if (error.response.status === 500) {
        toast.error("Server Error. Please try again later.");
        navigate("/");
      } else {
        toast.error("An error occurred. Please try again later.");
        navigate("/");
      }
    }
  } else if (method === "POST") {
    try {
      const response = await axios.post(url, data);
      console.log(response.data);
      return response.data;
    } catch (error) {
      console.error("Error in API call:", error);
      if (error.response.status === 401) {
        toast.error("You are not authorized to access this page. Please login first.");
        navigate("/login");
      } else if (error.response.status === 404) {
        toast.error("The requested resource was not found.");
        navigate("/");
      } else if (error.response.status === 500) {
        toast.error("Server Error. Please try again later.");
        navigate("/");
      } else {
        toast.error("An error occurred. Please try again later.");
        navigate("/");
      }
    }
  }
};

export default ApiCall;

Make axios call using protected function

import ApiCall from "../../util/ApiCall";
import { useNavigate } from "react-router-dom";

const Discover = () => {
  const navigate = useNavigate();

  useEffect(() => {
    const getUser = async () => {
      const response = await ApiCall("/user/getDetails", "GET", navigate, null);
      console.log(response.data);
      setUser(response.data.name);
    };
    getUser();
  }, []);

  return <></>;
};

export default Discover;

Send post request with token¶

const config = {
                headers: {
                    Authorization: `Bearer ${
                        JSON.parse(localStorage.getItem("userInfo")).jwt
                    }`,
                },
            };
            const res = await axios.post(
                "/admin/sendTicketafterVerification/",
                {},
                config
            );
            console.log("After Sending Ticket", res);

Send get request with token¶

const response = await axios.get(
                `/admin/verify/${props.details._id}`,
                config
            );

How to show uploading of file in frontend¶

Yes, you can add a feature to show the upload percentage of the file using Axios's onUploadProgress event. This event allows you to track the progress of the upload and update the state accordingly. Here's how you can do it:

Updated Frontend Code with Upload Progress¶

FileUpload.js:

import React, { useState } from 'react';
import axios from 'axios';

const FileUpload = () => {
  const [file, setFile] = useState(null);
  const [name, setName] = useState('');
  const [message, setMessage] = useState('');
  const [uploadPercentage, setUploadPercentage] = useState(0);

  const handleFileChange = (e) => {
    setFile(e.target.files[0]);
  };

  const handleNameChange = (e) => {
    setName(e.target.value);
  };

  const handleSubmit = async (e) => {
    e.preventDefault();
    const formData = new FormData();
    formData.append('file', file);
    formData.append('name', name);

    try {
      const res = await axios.post('http://localhost:5000/upload', formData, {
        onUploadProgress: (progressEvent) => {
          const { loaded, total } = progressEvent;
          const percent = Math.round((loaded * 100) / total);
          setUploadPercentage(percent);
        },
      });

      setMessage(res.data.message);
      setUploadPercentage(0); // Reset progress bar on successful upload
    } catch (err) {
      console.error(err);
      setMessage('Upload failed');
      setUploadPercentage(0); // Reset progress bar on error
    }
  };

  return (
    <div>
      <form onSubmit={handleSubmit}>
        <input type="text" placeholder="Enter name" value={name} onChange={handleNameChange} />
        <input type="file" onChange={handleFileChange} />
        <button type="submit">Upload</button>
      </form>
      {uploadPercentage > 0 && (
        <div>
          <progress value={uploadPercentage} max="100">{uploadPercentage}%</progress>
          <span>{uploadPercentage}%</span>
        </div>
      )}
      <p>{message}</p>
    </div>
  );
};

export default FileUpload;

Explanation:¶

State Management:
uploadPercentage: State to keep track of the upload percentage.
Event Handlers:
handleFileChange: Updates the file state when a file is selected.
handleNameChange: Updates the name state when the input value changes.
handleSubmit: Handles form submission, sets up the FormData, and makes the Axios request with onUploadProgress.
Axios Request:
The onUploadProgress event is used to track the upload progress. It receives a progressEvent object, from which you can extract the loaded and total bytes.
Calculate the upload percentage and update the uploadPercentage state.
Render:
Displays a progress bar and percentage text if uploadPercentage is greater than 0.
Shows the response message or an error message after the upload attempt.

Backend Code (unchanged):¶

server.js:

const express = require('express');
const multer = require('multer');
const path = require('path');

const app = express();
const PORT = 5000;

// Set up storage engine
const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, 'uploads/');
  },
  filename: (req, file, cb) => {
    cb(null, `${Date.now()}-${file.originalname}`);
  },
});

// Initialize upload
const upload = multer({ storage });

// Middleware to handle file upload and name
app.post('/upload', upload.single('file'), (req, res) => {
  try {
    const { name } = req.body;
    console.log(req.file); // File information
    console.log(name); // Name information
    res.status(200).json({ message: 'File and name uploaded successfully', file: req.file, name });
  } catch (error) {
    console.error(error);
    res.status(500).json({ message: 'Upload failed', error });
  }
});

app.listen(PORT, () => {
  console.log(`Server is running on http://localhost:${PORT}`);
});

Summary¶

The frontend code now includes an upload progress bar that updates in real-time using Axios's onUploadProgress event.
The progress bar and percentage are displayed during the file upload process, providing feedback to the user.

With this implementation, users will see a progress bar indicating the percentage of the file that has been uploaded, enhancing the user experience.