File Uploader

A component to allow users to upload files and display their status.

import { FileUploader, FileStatus, processStatus } from '@cerberus/react'

Uploading Files

To allow users to upload files, use the FileUploader component. This will provide a drag-and-drop area for users to upload files which is also clickable.

Once a valid file is added, a preview card of the file will be displayed.

import { FileUploader } from '@cerberus/react'

export function BasicFileUploader() {
  return (
    <FileUploader
      accept="image/*"
      heading="Upload Files"
      name="basic-example"
    />
  )
}

File Status

If you choose to process the file, you can use the FileStatus component to display the status of the job.

'use client'

import {
  FileStatus,
  type FileStatusActions,
  processStatus,
} from '@cerberus/react'
import { vstack } from 'styled-system/patterns'
import { useCallback, type MouseEvent } from 'react'

export function UploadingCardsPreview() {
  const handleClick = useCallback(
    (status: FileStatusActions, e: MouseEvent<HTMLButtonElement>) =>
      console.log(status, e),
    [],
  )

  return (
    <div
      className={vstack({
        maxW: '36rem',
        w: '3/4',
      })}
    >
      <FileStatus
        id="todo"
        file="file.txt"
        now={0}
        onClick={handleClick}
        status={processStatus.TODO}
      />
      <FileStatus
        id="processing"
        file="file.txt"
        now={50}
        onClick={handleClick}
        status={processStatus.PROCESSING}
      />
      <FileStatus
        id="done"
        file="file.txt"
        now={100}
        onClick={handleClick}
        status={processStatus.DONE}
      />
      <FileStatus
        id="error"
        file="file.txt"
        now={0}
        onClick={handleClick}
        status={processStatus.ERROR}
      />
    </div>
  )
}

Accepted File Types

Use the accept prop to restrict the file types that can be uploaded. This prop accepts MIME types (e.g., image/png, image/jpeg) or file extensions (e.g., .pdf, .txt).

When users attempt to upload files that don't match the accepted types, these files will be automatically rejected and appear in the rejectedFiles array with a FILE_INVALID_TYPE error code.

import { FileUploader } from '@cerberus-design/react';

<FileUploader
  id="file-uploader"
  accept="image/png, image/jpeg"
/>

Error Handling

The FileUploader component provides comprehensive validation and error handling capabilities. You can set various constraints and handle different types of validation errors:

Built-in Validation Props:

maxFiles - Maximum number of files allowed
maxFileSize - Maximum file size in bytes
minFileSize - Minimum file size in bytes
accept - Allowed MIME types or file extensions

Built-in Error Types:

TOO_MANY_FILES - Exceeds maxFiles limit
FILE_INVALID_TYPE - File type not in accept list
FILE_TOO_LARGE - File size exceeds maxFileSize
FILE_TOO_SMALL - File size below minFileSize
FILE_INVALID - Generic validation failure
FILE_EXISTS - Duplicate file detected

import {
  FileUploader,
  FileUploadParts,
  createErrorMessages,
  Text,
} from '@cerberus/react'

const errorMessages = createErrorMessages({
  TOO_MANY_FILES: '📊 Too many files selected (max 3 allowed)',
  FILE_INVALID_TYPE: '🚫 Invalid file type (only images and PDFs allowed)',
  FILE_TOO_LARGE: '📏 File too large (max 1MB)',
  FILE_TOO_SMALL: '📐 File too small (min 1KB)',
  FILE_INVALID: '⚠️ Invalid file',
  FILE_EXISTS: '🔄 File already exists',
})

export const ErrorHandling = () => {
  return (
    <FileUploader
      maxFiles={3}
      maxFileSize={1024 * 1024} // 1MB
      minFileSize={1024} // 1KB
      accept="image/*,application/pdf"
      showPreview={false}
    >
      <div data-status="rejected">
        <Text textStyle="heading-md">❌ Rejected Files</Text>

        <FileUploadParts.ItemGroup>
          <FileUploadParts.Context>
            {({ rejectedFiles }) =>
              rejectedFiles.length === 0 ? (
                <Text>No rejected files</Text>
              ) : (
                rejectedFiles.map((fileRejection) => (
                  <FileUploadParts.Item
                    key={fileRejection.file.name}
                    file={fileRejection.file}
                    data-status="rejected"
                  >
                    <FileUploadParts.ItemName />
                    <FileUploadParts.ItemSizeText />
                    <div>
                      <Text as="strong">Validation Errors:</Text>
                      {fileRejection.errors.map((error, index) => (
                        <div key={index} data-error-code={error}>
                          {errorMessages[error as FileUploadFileError] || `❓ ${error}`}
                        </div>
                      ))}
                    </div>
                  </FileUploadParts.Item>
                ))
              )
            }
          </FileUploadParts.Context>
        </FileUploadParts.ItemGroup>
      </div>
    </FileUploader>
  )
}

Error Helpers

To easily create error messages for the built-in error types, use the createErrorMessages function:

createErrorMessages({
  tooMany: 'Too many files were selected',
  invalidType: 'This is not a valid file type',
  tooLarge: 'File size exceeds the maximum allowed (3KB)',
  tooSmall: 'File size must be at least 1KB',
  invalid: 'File type is not supported. Please select a valid file type.',
  exists: 'File already exists'
})

All of the properties within the options Object are optional and will provide the following default error messages if not provided:

{
  TOO_MANY_FILES: options.tooMany || '📊 Too many files selected',
  FILE_INVALID_TYPE: options.invalidType || '🚫 Invalid file type',
  FILE_TOO_LARGE: options.tooLarge || '📏 File too large',
  FILE_TOO_SMALL: options.tooSmall || '📐 File too small',
  FILE_INVALID: options.invalid || '⚠️ Invalid file',
  FILE_EXISTS: options.exists || '🔄 File already exists',
}

File Transformations

Use the transformFiles prop to process files before they're added to the accepted files list. This is useful for file compression, format conversion, or adding metadata.

Common transformation use cases:

Image compression: Use image-conversion, browser-image-compression, or similar libraries
Format conversion: Convert files to different formats (e.g., HEIC to JPEG)
Metadata extraction: Add EXIF data or other file information
File validation: Perform additional checks beyond basic validation
Resizing: Automatically resize images to specific dimensions

import { FileUploader } from '@cerberus/react/file-upload'
import { compressAccurately } from 'image-conversion'

function FileTransformationsDemo() {
  const transformFiles = async (files: File[]) => {
    return Promise.all(
      files.map(async (file) => {
        if (file.type.startsWith('image/')) {
          try {
            // Compress image to ~200KB
            const blob = await compressAccurately(file, 200)
            return new File([blob], file.name, { type: blob.type })
          } catch (error) {
            console.error('Compression failed for:', file.name, error)
            return file
          }
        }
        return file // Return non-image files as-is
      }),
    )
  }

  return (
    <FileUploader
      accept="image/*"
      maxFiles={5}
      transformFiles={transformFiles}
    />
  )
}

Custom Validation

Use the validate prop to implement custom validation logic beyond the built-in constraints.

<FileUploadParts.Root
  validate={(file) => {
    if (file.name.length > 20) return ['FILE_NAME_TOO_LONG']
    return null
  }}
/>

Guides

File Previews

The FileUpload component provides flexible preview options for different file types. Use ItemPreview with type matching to show appropriate previews based on file format.

Preview Types:

type="image/*": Shows image thumbnails using ItemPreviewImage
type="video/*": For video file previews
type="application/pdf": For PDF files
type=".*": Generic fallback for any file type

<FileUploadParts.ItemPreview type="image/*">
  <FileUploadParts.ItemPreviewImage />
</FileUploadParts.ItemPreview>

<FileUploadParts.ItemPreview type="video/*">
  <VideoIcon />
</FileUploadParts.ItemPreview>

<FileUploadParts.ItemPreview type="application/pdf">
  <PdfIcon />
</FileUploadParts.ItemPreview>

<FileUploadParts.ItemPreview type=".*">
  <FileIcon />
</FileUploadParts.ItemPreview>

File Metadata Display:

ItemName - Shows the file name
ItemSizeText - Shows formatted file size (e.g., "2.5 MB")

Disable dropzone

To disable drag-and-drop functionality, set the allowDrop prop to false.

<FileUploader allowDrop={false} />

Prevent document drop

By default, when the dropzone is active, we prevent accidental navigation when files are dropped outside the dropzone. To prevent this behavior, set the preventDocumentDrop prop to false.

<FileUploader preventDocumentDrop={false} />

Prevent double open

When you want to delegate clicking to the trigger and remove the dropzone from the tab order, you can use the disableClick prop. This prevents the the file picker from opening twice.

<FileUploadParts.Dropzone disableClick>
  <FileUploadParts.Trigger>Choose Files</FileUploadParts.Trigger>
  Drag files here
</FileUploadParts.Dropzone>

Primitives

You can utilize the primitive components or the style props to customize the file uploader.

Component	Description
FileUploadRoot	The context provider for the FileUploader parts
FileUploadTrigger	The trigger of the FileUploader
FileUploadDropzone	The dropzone of the FileUploader
FileUploadLabel	The label of the FileUploader
FileUploadTrigger	The trigger of the FileUploader
FileUploadClearTrigger	The clear trigger of the FileUploader
FileUPloadItemGroup	The container for the group of items
FileUploadItem	The container for the item
FileUploadItemPreview	The container of hte preview for the item
FileUploadItemPreviewImage	The image preview for the item
FileUploadItemName	The name of the item
FileUploadItemSizeText	The size text of the item
FileUploadItemDeleteTrigger	The delete trigger of the FileUploader
FileUPloadHiddenInput	The hidden input of the FileUploader
FileUploadContext	The context of the FileUploader
FileUploadIcon	The icon of the FileUploader
FileUploadHeading	The heading of the FileUploader
FileUploadDescription	The description of the FileUploader

API

FileUploader

Prop	Type	Description
`accept`	`Record<string, string[]>`	The accept file types
`acceptedFiles`	`File[]`	The controlled accepted files
`allowDrop`	`boolean`	Whether to allow drag and drop in the dropzone element
`asChild`	`boolean`	Use the provided child element as the default rendered element, combining their props and behavior.
`capture`	`'user' or 'environment'`	The default camera to use when capturing media
`defaultAcceptedFiles`	`File[]`	The default accepted files when rendered. Use when you don't need to control the accepted files of the input.
`directory`	`boolean`	Whether to accept directories, only works in webkit browsers
`disabled`	`boolean`	Whether the file input is disabled
`ids`	`Partial<PrimitiveStack>`	The ids of the elements. Useful for composition.
`invalid`	`boolean`	Whether the file input is invalid
`locale`	`string`	The current locale. Based on the BCP 47 definition.
`maxFiles`	`number`	The maximum number of files
`maxFileSize`	`number`	The maximum file size in bytes
`minFileSize`	`number`	The minimum file size in bytes
`name`	`string`	The name of the underlying file input
`onFileAccept`	`(details: FileAcceptDetails) => void`	Function called when the file is accepted
`onFileChange`	`(details: FileChangeDetails) => void`	Function called when the value changes, whether accepted or rejected
`onFileReject`	`(details: FileRejectDetails) => void`	Function called when the file is rejected
`preventDocumentDrop`	`boolean`	Whether to prevent the drop event on the document
`required`	`boolean`	Whether the file input is required
`transformFiles`	`(files: File[]) => Promise<File[]>`	Function to transform the accepted files to apply transformations
`translations`	`IntlTranslations`	The localized messages to use.
`validate`	`(file: File, details: FileValidateDetails) => FileError[] or null`	Function to validate a file
`heading`	`string`	The heading for the file uploader
`showPreview`	`boolean`	Whether to show the preview of the file or custom children.

Root Data Attributes:

Attribute	Value
`[data-scope]`	file-upload
`[data-part]`	root
`[data-disabled]`	Present when disabled
`[data-dragging]`	Present when in the dragging state

FileStatus

The FileStatus component accepts the following props:

Name	Default	Description
`id`		A unique identifier for the ProgressBar.
`file`		The name of the file being processed
`now`		The current progress of the file upload
`status`	`'todo'`	The status of the file upload

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