Image upload using Golang and React

Golang is a blockbuster server side language in the field of efficiency and concurrency. If you are a Nodejs developer definitely you will come across express js for building your web api services. Gofiber is exactly like the express framework for golang and no doubt it booms with the efficiency of Fasthttp and golang.

In this blog post we will create a simple image upload server using gofiber and we will use reactjs for frontend to select image from file and upload to server.

we will use axios for http request to server and it is really awesome when we deal with implementing authentication and handling lots of api requests. It has lots of features which make life easy when dealing with api in react.

we will use chakra ui for designing material like button , images and layout it shins in Accessibility that directly effect better SEO.

library and tools we will use

golang

gofiber

reactjs

axios

chakra ui

Setup backend

create new directory and enter into it

mkdir go-react-image-upload

cd go-react-image-upload

create a new directory server inside go-react-image-upload and enter into it

mkdir server 

cd server

Setup go environment

go mod init github.com/harshmangalam

install packages required for backend

go get  github.com/gofiber/fiber/v2

go get github.com/google/uuid

uuid will help to generate unique id so that we can name our image easily and no two image will have same name.

create new go file main.go inside server and start writting code

package main

import (
    "fmt"
    "log"
    "os"
    "strings"

    "github.com/gofiber/fiber/v2"
    "github.com/gofiber/fiber/v2/middleware/cors"
    "github.com/google/uuid"
)

func main() {
    // create new fiber instance  and use across whole app
    app := fiber.New()

    // middleware to allow all clients to communicate using http and allow cors
    app.Use(cors.New())

    // serve  images from images directory prefixed with /images
    // i.e http://localhost:4000/images/someimage.webp

    app.Static("/images", "./images")

    // handle image uploading using post request

    app.Post("/", handleFileupload)

    // delete uploaded image by providing unique image name

    app.Delete("/:imageName", handleDeleteImage)

    // start dev server on port 4000

    log.Fatal(app.Listen(":4000"))
}



func handleFileupload(c *fiber.Ctx) error {

    // parse incomming image file

    file, err := c.FormFile("image")

    if err != nil {
        log.Println("image upload error --> ", err)
        return c.JSON(fiber.Map{"status": 500, "message": "Server error", "data": nil})

    }

    // generate new uuid for image name 
    uniqueId := uuid.New()

    // remove "- from imageName"

    filename := strings.Replace(uniqueId.String(), "-", "", -1)

    // extract image extension from original file filename

    fileExt := strings.Split(file.Filename, ".")[1]

    // generate image from filename and extension
    image := fmt.Sprintf("%s.%s", filename, fileExt)

    // save image to ./images dir 
    err = c.SaveFile(file, fmt.Sprintf("./images/%s", image))

    if err != nil {
        log.Println("image save error --> ", err)
        return c.JSON(fiber.Map{"status": 500, "message": "Server error", "data": nil})
    }

    // generate image url to serve to client using CDN

    imageUrl := fmt.Sprintf("http://localhost:4000/images/%s", image)

    // create meta data and send to client

    data := map[string]interface{}{

        "imageName": image,
        "imageUrl":  imageUrl,
        "header":    file.Header,
        "size":      file.Size,
    }

    return c.JSON(fiber.Map{"status": 201, "message": "Image uploaded successfully", "data": data})
}


func handleDeleteImage(c *fiber.Ctx) error {
    // extract image name from params
    imageName := c.Params("imageName")

    // delete image from ./images
    err := os.Remove(fmt.Sprintf("./images/%s", imageName))
    if err != nil {
        log.Println(err)
        return c.JSON(fiber.Map{"status": 500, "message": "Server Error", "data": nil})
    }

    return c.JSON(fiber.Map{"status": 201, "message": "Image deleted successfully", "data": nil})
}

run main.go from server

go run main.go

Now our server is up and running we can test it using Postman

setup frontend

come outside from server directory and generate reactjs project using create-react-app

npx create-react-app reactjs

cd reactjs

install dependencies

npm i @chakra-ui/react @emotion/react@^11 @emotion/styled@^11 framer-motion@^4 axios

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';


ReactDOM.render(

  <App />
  ,
  document.getElementById('root')
);

setup App.js

import { Box, ChakraProvider, Container } from "@chakra-ui/react";
import Axios from "axios";
import Upload from "./components/Upload";

Axios.defaults.baseURL = "http://localhost:4000";

function App() {
  return (
    <ChakraProvider>
      <Box
        minH="100vh"
        w="100%"
        bg="gray.200"
        display="flex"
        alignItems="center"
        justifyContent="center"
      >
        <Container maxWidth="container.xl">
          <Upload />
        </Container>
      </Box>
    </ChakraProvider>
  );
}

export default App;

create new hook useUpload hook in hooks folder

hooks/useUpload.js

import { useState } from "react";
import axios from "axios";
import { useToast } from "@chakra-ui/react";

const useUpload = () => {
  const [image, setImage] = useState(null);
  const [loading, setLoading] = useState(false);

  const [uploadedImage, setUploadedImage] = useState(null);

  const toast = useToast();

  const handleChangeImage = (e) => {
    setImage(e.target.files[0]);
  };

  const handleUploadImage = async () => {
    try {
      setLoading(true);
      const formData = new FormData();
      formData.append("image", image);
      const res = await axios.post("/", formData);
      if (res.data.data) {
        console.log(res.data);
        setUploadedImage(res.data.data);
        toast({
          title: "Image Uploaded",
          description: res.data.message,
          status: "success",
          duration: 4000,
          isClosable: true,
        });
      }
    } catch (error) {
      console.log(error);
    } finally {
      setImage(null);
      setLoading(false);
    }
  };

  const handleRemoveImage = async () => {
    try {
      setLoading(true);

      const res = await axios.delete(`/${uploadedImage.imageName}`);
      if (res.data) {
        console.log(res.data);
        setUploadedImage(null);
        toast({
          title: "Image Deleted",
          description: res.data.message,
          status: "success",
          duration: 4000,
          isClosable: true,
        });
      }
    } catch (error) {
      console.log(error);
    } finally {
      setLoading(false);
    }
  };
  return {
    image,
    uploadedImage,
    loading,
    handleChangeImage,
    handleUploadImage,
    handleRemoveImage,
  };
};

export default useUpload;

create Upload.js inside components folder

components/Upload.js

import { Button, Heading, VStack, Image, HStack, Tag } from "@chakra-ui/react";
import React from "react";
import { useRef } from "react";
import useUpload from "../hooks/useUpload";

function Upload() {
  const imageRef = useRef(null);
  const {
    loading,
    image,

    handleRemoveImage,
    handleChangeImage,
    handleUploadImage,
    uploadedImage,
  } = useUpload();
  return (
    <>
      <input
        style={{ display: "none" }}
        type="file"
        accept="image/*"
        ref={imageRef}
        onChange={handleChangeImage}
      />
      <VStack>
        <Heading>Image uploading using Golang and Reactjs</Heading>
        <Button
          onClick={() => imageRef.current.click()}
          colorScheme="blue"
          size="lg"
        >
          Select Image
        </Button>
      </VStack>

      {image && (
        <VStack my="4">
          <Image
            src={URL.createObjectURL(image)}
            width="300px"
            height="300px"
            alt="selected image..."
          />
          <Button
            onClick={handleUploadImage}
            variant="outline"
            colorScheme="green"
            isLoading={loading}
          >
            Upload
          </Button>
        </VStack>
      )}

      {uploadedImage && (
        <VStack my="4">
          <Image
            src={uploadedImage.imageUrl}
            width="300px"
            height="300px"
            alt={uploadedImage.imageName}
          />

          <HStack>
            <Tag variant="outline" colorScheme="blackAlpha">
              ~ {Math.floor(uploadedImage.size / 1024)} Kb
            </Tag>
            <Button
              variant="solid"
              colorScheme="red"
              onClick={handleRemoveImage}
              isLoading={loading}
            >
              Delete
            </Button>
          </HStack>
        </VStack>
      )}
    </>
  );
}

export default Upload;