validateFileList.md

sidebar_position	sidebar_label	title	description
4	validateFileList	validateFileList	Validates a list of files based on size limit and extension to return an array of acceptedFiles, rejectedFiles and errors.

validateFileList

type ProcessFilesResult = {
  acceptedFiles: File[];
  rejectedFiles?: File[]; 
  errors?: FileUploadError[];
}

function validateFileList(
  fileList: FileList,
  accept?: string
  maxSize?: number,
  maxFiles?: number;
): ProcessFilesResult

validateFileList function processes a list of uploaded files, validating each file against:

• Maximum file size in bytes (if provided)
• Accepted file types (based on the accept attribute)

This function utilized by RHFFileUploader ensures only files meeting the required criteria are passed for further processing.

Usage

import { validateFileList } from '@nish1896/rhf-mui-components/form-helpers';

Parameters

1. fileList: The set of input files to run this validation against.

2. accept: An optional string that specifies the allowed file types or extensions, following the standard input[type="file"] accept attribute format (e.g., .png, .jpg, image/*). Files not matching the criteria will be rejected.

3. maxSize: An optional numeric value (in bytes) that sets the maximum allowed file size. Files exceeding this limit will be rejected.

4. maxFiles: Maximum number of files allowed for upload. Any additional files, even if valid, will be added to the rejectedFiles array and excluded from the accepted files.

Returns

• acceptedFiles: A list of accepted files.
• rejectedFiles: A list of rejected files.
• errors: A set of validation errors which can be any of:
  • FILE_SIZE_EXCEEDED
  • FILE_TYPE_NOT_ALLOWED
  • FILE_LIMIT_EXCEEDED

Examples

// Allow any file, but max allowed size for each file should be 5 MB.
validateFileList(fileList, '*', 5 * 1024 * 1024);

// Allow only image mimetype
validateFileList(fileList, 'image/*');

// Allow at max 3 files
validateFileList(fileList, undefined, undefined, 3);