Handle Files React

npm

Description

Easy and Quick way to handle files in React with <Dropzone/> and useFileInput() hook.

Installation

npm install handle-files-react
yarn add handle-files-react
pnpm add handle-files-react

Quick Start

useFileInput()

import { useFileInput, FileWithMeta, convertToBytes } from 'handle-files-react';

function App(){
    const { open } = useFileInput();
    const [files, setFiles] = useState<FileWithMeta[]>([]);
    
    return (
        <div>
            <button onClick={async ()=>{
                try {
                    const files = await open({
                        multiple: true,
                        maxBytes: convertToBytes(10, "MB"), // 10MB
                        accept: ["image/*", "video/mp4"], // native input accept attribute
                        maxFiles:5,
                        customValidator: (file) => file.name.includes("Blender")
                    });
                    setFiles(files);
                } catch (e) {
                    console.error(e);
                }
            }}>Select</button>
            <ul>
                {files.map((file) => (
                    <li key={file.origin.name}>
                        {file.origin.name} ({file.toUnit("MB", 1)})
                    </li>
                ))}
            </ul>
        </div>
    )
}

<Dropzone/>

function App() {
    const [files, setFiles] = useState<FileWithMeta[]>([]);
    const [refEl, setRefEl] = useState<HTMLDivElement | null>(null);
    return (
        <div>
            <DropZone
                onDrop={(files) => {
                    setFiles(files);
                }}
                onError={(e) => {
                    console.error(e);
                }}
                multiple={true}
                maxBytes={convertToBytes(10, "MB")}
                accept={["image/*"]}
                maxFiles={5}
                customValidator={(file) => {
                    return file.name.includes("Blender");
                }}
            >
                <div
                    ref={(el) => {
                        if(!refEl) {
                            setRefEl(el); // use ref element with state
                        }
                    }}
                    style={{
                        width: 500,
                        height: 500,
                        backgroundColor: "gray",
                    }}
                >
                    DROP ZONE
                    <ul>
                        {files.map((file) => (
                            <li key={file.origin.name}>
                                {file.origin.name} ({file.toUnit("MB", 1)})
                            </li>
                        ))}
                    </ul>
                </div>
            </DropZone>
        </div>
    );
}

customValidator

return boolean or Promise<boolean> or throw Error

If you want to get message onError callback, you can throw Error. Returning boolean or Promise<boolean> will get default message.

1. Throw Error

<DropZone
    onError={(e) => {
        setErrorMsg(e.message); // e.message is ".wav extension is not allowed"
    }}
    accept={["audio/mpeg"]}
    customValidator={(file) => {
        if (file.name.includes("wav")) {
            throw new Error(".wav extension is not allowed");
        }
        return true;
    }}
/>

2. Return boolean

<DropZone
    onError={(e) => {
        setErrorMsg(e.message); // `Custom validation failed: ${file.name}`
    }}
    maxBytes={convertToBytes(10, "MB")}
    customValidator={(file) => {
        if (file.size > convertToBytes(10, "MB")) {
            return false;
        }
        return true;
    }}
/>

3. Return Promise

<DropZone
    onError={(e) => {
      setErrorMsg(e.message); // `timeout error`
    }}
    accept={["audio/mpeg"]}
    customValidator={async (file) => {
      await new Promise((resolve) => setTimeout(resolve, 1000));
      throw new Error("timeout error");
        return true;
    }}
>

accept options

accept option is used to filter the file type and use the File.type property. (not the file extension)
It works like the native input accept attribute. so, it supports string or string[].

// 1. string[]  
const files = await open({
accept: ["image/*", "video/mp4"], // same with <input accept="image/*, video/mp4">
});

// 2. string
const files2 = await open({
    accept: "image/*, video/mp4", // same with <input accept="image/*, video/mp4">
});

API

common

const units = [
    "B",
    "KB",
    "MB",
    "GB",
    "TB",
    "PB",
    "EB",
    "ZB",
    "YB",
] as const;

interface FileInputOptions {
  multiple?: boolean;
  accept?: string | string[]; // MIME type
  maxBytes?: number;
  maxFiles?: number;
  customValidator?: (file: File) => boolean | Promise<boolean>;
};

interface FileWithMeta {
    origin: File;
    toUnit: TGetUnit;
}

useFileInput()

function useFileInput(){
    const open = (options?: FileInputOptions) => {
        // ...
    }
    return { open };
}

<Dropzone/>

interface Props {
    children: React.ReactElement;
    onDrop: (files: FileWithMeta[]) => void;
    onError?: (error: Error) => void;
    onDragEnter?: (e: React.DragEvent) => void;
    onDragLeave?: (e: React.DragEvent) => void;
}

function DropZone(props:Props & FileInputOptions){
    // return clone children
}

Util funcitons

convertToBytes(value: number, unit: TUnit): number

value * 1024^index (index is the index of the unit in the units array)

convertToBytes(10, "MB"); // 10485760
convertToBytes(10, "GB"); // 10737418240
convertToBytes(10, "TB"); // 10995116277760

FileWithMeta.toUnit(unit: TUnit, fixed?: number): string

fileWithMeta.toUnit("MB", 1); // 10.0MB
fileWithMeta.toUnit("GB", 2); // 10.00GB
fileWithMeta.toUnit("TB", 3); // 10.000TB

getUnitFunc(bytes: number): TGetUnit

const toUnit = getUnitFunc(10485760);
toUnit("MB", 1); // 10.0MB

getFileDuration(file: File):Promise<number>

Get the duration of the video, audio file.

const duration = await getFileDuration(file); // seconds
console.log(duration); // 10.0

Tips

Infer the type of the file

accept option is used to filter the file type and use the File.type property.
Here, is the situation where image.ai is not an type of .ai but application/postscript.
But you can get actual file type by error.