How to Upload CSV Files in Reactjs

There are are multiple ways to upload file, we can upload file directly choosing from files or also upload files by drag and drop method, so in this this blog  I will be covering how to upload CSV file by drag and drop method using Reactjs and also I will be covering about how to apply size restrictions and which browser supports CSV upload and also how to install library and call that component.

I will explain the CSV file upload implementation in a simple way, I will mention the points below to use CSV file upload;

1. Library required to CSV file upload to your project
2. Browser supports
3. Calling the file drop component.
4. Handling different events.
5. Calling and implementing ondrop function
6. Advantages
7. Conclusion

1. Library Required To CSV File Upload To Your Project

We can use different types of libraries to use CSV file upload drag but we will be using React-file-drop library with the latest version of 3.0.7 for uploading CSV files by drag and drop.

npm i react-file-drop

2. Browser Supports

Most important thing before implementing any functionality we need to check is browser support which means whether the functionality is working on the respective browsers and whether it is feasible or not. The browser which supports the react file drop are given below.

• Chrome
• Firefox
• Safari
• IE 11
• IE Edge

3. Calling File Drop Component

Calling a file drop component is an important step in this blog. We have to add a file drop component name in reader so that we can call it,also we have to handle some event in that component.
– add component in render

<FileDrop > </FileDrop>

and also need to add different event in File drop component so that we have can handle events as shown below:

<FileDrop 

         onFrameDragEnter={(event) => console.log('onFrameDragEvent',event)}

         onFrameDragLeave={(event) => console.log('onFrameDragEvent',event)}

         onFrameDrop={(event) => console.log('onFrameDropEvent', event)}

         onDragOver={(event) => console.log('onDragOverEvent', event)}

         onDragLeave={(event) => console.log('onDragLeaveEvent', event)}

         onDrop={(files, event) =>  console.log('onDropEvent', event)}

       >

       </FileDrop>

4. Handling Different Events

5. Calling And Implementing Ondrop Function

We have to handle ondrop event so we will calling a function on drop event as shown below

<FileDrop 

         onFrameDragEnter={(event) => console.log('onFrameDragEvent',event)}

         onFrameDragLeave={(event) => console.log('onFrameDragEvent',event)}

         onFrameDrop={(event) => console.log('onFrameDropEvent', event)}

         onDragOver={(event) => console.log('onDragOverEvent', event)}

         onDragLeave={(event) => console.log('onDragLeaveEvent', event)}

         onDrop={(files, event) => this.onDropFunction(files)

}

We call the onDropFunction and pass files as a parameter.
Implementation on the function is given below

 drag_and_dropFile  ( files) {

          for(var i in files){

                             var file_type=files[i].type

                             var  file_size=files[i].size

               if( file_type === “text/CSV”){

                   console.log(“CSV file”)

                    }

               else{ 

                    console.log(“provide valid file type”)  

}                                              }}

We can also check the file type as shown above, and we can also check the file size and also apply validations on it as shown below

for (i in files){

var file_size=files[i].size

var file_size_in_unit

if (file_size < 1024) {

        console.log(file_size + " Bytes");

        file_size_in_unit=file_size

                               }

else if (file_size < 1048576) {

         console.log("KB:" + (file_size / 1024).toFixed(3) + " KB");

         file_size_in_unit=(file_size / 1024).toFixed(3) 

                                             }

else if (file_size < 1073741824) {

          console.log("MB:" + (file_size / 1048576).toFixed(2) + " MB");

          file_size_in_unit= (file_size / 1048576).toFixed(2)

        If(file_size_in_unit  > 25){

                 console.log("File size is greater than 25MB")

                                              }

                                                   }

                       }

6. Advantages Of This Approach

• Multiple browser support.
• Drag and drop multiple files at a time.
• Can allow restrictions for file type and size.

Code Snippet

import React, { Component } from 'react'

import { FileDrop } from 'react-file-drop

export class AddCSVFile extends Component {

    constructor(props) {

        super(props);

        this.state = { }

    }

   drag_and_dropFile  ( files) {

           for (i in files){

                             var file_type=files[i].type

                             var  file_size=files[i].size

               if( file_type === “text/CSV”){

                   console.log(“CSV file”)

                    }

               else{ 

                    console.log(“provide valid file type”)  

}                                              }

}

render() {


       return (

<div>

 <FileDrop