File Uploads in React

This part builds upon the previous GraphQL operations part by demonstrating how to implement file upload functionality with proper storage permissions. You’ll learn how to create storage buckets, configure upload permissions, and implement complete file management operations in a React application.

Note

This is Part 5 in the Full-Stack React Development with Nhost series. This part focuses on file storage, upload operations, and permission-based file access control in a production application.

Full-Stack React Development with Nhost

1. Create Project

Set up your Nhost project

2. Protected Routes

Route protection basics

3. User Authentication

Complete auth flow

4. GraphQL Operations

CRUD operations with GraphQL

5. File Uploads

Current - File upload and management

Prerequisites

• Complete the GraphQL Operations part first
• The project from the previous part set up and running

What You’ll Build

By the end of this part, you’ll have:

• A personal bucket so users can upload their own private files
• File upload functionality
• File management interface for viewing and deleting files
• Security permissions ensuring users can only access their own files

Step-by-Step Guide

Create a Personal Storage Bucket

First, we’ll create a storage bucket where users can upload their personal files.

In your Nhost project dashboard:

1. Navigate to Database
2. Change to schema.storage, then buckets
3. Now click on + Insert on the top right corner.
4. As id set personal, leave the rest of the fields blank and click on Insert at the bottom

Configure Storage Permissions

Now we need to set up permissions for the storage bucket to ensure the user role can only upload, view, and delete their own files.

Upload

To upload files we need to grant permissions to insert on the table storage.files. Because we want to allow uploading files only to the personal bucket we will be using the bucket_id eq personal as a custom check. In addition, we are configuring a preset uploaded_by_user_id = X-Hasura-User-id, this will automatically extract the user_id from the session and set the column accordingly. Then we can use this in other permissions to allow downloading files and deleting them.

Download

To download files users need to be able to query those files. To make sure users can only download files they uploaded we will be leveraging the column uploaded_by_user_id column from before and the `bucket_id“.

Delete

Similarly to downloading files, to delete files users need to be able to delete rows from the storage.files table. Again we will use the uploaded_by_user_id column and the bucket_id to make sure users can only delete their own files.

Note

You can read more about storage permissions here

Create the File Upload Component

Now let’s implement the React component for file upload functionality.

import type { FileMetadata } from "@nhost/nhost-js/storage";
import { type JSX, useCallback, useEffect, useRef, useState } from "react";
import { useAuth } from "../lib/nhost/AuthProvider";

interface DeleteStatus {
  message: string;
  isError: boolean;
}

interface GraphqlGetFilesResponse {
  files: FileMetadata[];
}

function formatFileSize(bytes: number): string {
  if (bytes === 0) return "0 Bytes";

  const sizes: string[] = ["Bytes", "KB", "MB", "GB", "TB"];
  const i: number = Math.floor(Math.log(bytes) / Math.log(1024));

  return `${parseFloat((bytes / 1024 ** i).toFixed(2))} ${sizes[i]}`;
}

export default function Files(): JSX.Element {
  const { isAuthenticated, nhost } = useAuth();
  const fileInputRef = useRef<HTMLInputElement | null>(null);
  const [selectedFile, setSelectedFile] = useState<File | null>(null);
  const [uploading, setUploading] = useState<boolean>(false);
  const [uploadResult, setUploadResult] = useState<FileMetadata | null>(null);
  const [isFetching, setIsFetching] = useState<boolean>(true);
  const [error, setError] = useState<string | null>(null);
  const [files, setFiles] = useState<FileMetadata[]>([]);
  const [viewingFile, setViewingFile] = useState<string | null>(null);
  const [deleting, setDeleting] = useState<string | null>(null);
  const [deleteStatus, setDeleteStatus] = useState<DeleteStatus | null>(null);

  const fetchFiles = useCallback(async (): Promise<void> => {
    setIsFetching(true);
    setError(null);

    try {
      // Use GraphQL to fetch files from the storage system
      // Files are automatically filtered by user permissions
      const response = await nhost.graphql.request<GraphqlGetFilesResponse>({
        query: `query GetFiles {
            files {
              id
              name
              size
              mimeType
              bucketId
              uploadedByUserId
            }
          }`,
      });

      if (response.body.errors) {
        throw new Error(
          response.body.errors[0]?.message || "Failed to fetch files",
        );
      }

      setFiles(response.body.data?.files || []);
    } catch (err) {
      console.error("Error fetching files:", err);
      setError("Failed to load files. Please try refreshing the page.");
    } finally {
      setIsFetching(false);
    }
  }, [nhost.graphql]);

  useEffect(() => {
    if (isAuthenticated) {
      fetchFiles();
    }
  }, [isAuthenticated, fetchFiles]);

  const handleFileChange = (e: React.ChangeEvent<HTMLInputElement>): void => {
    if (e.target.files && e.target.files.length > 0) {
      const file = e.target.files[0];
      if (file) {
        setSelectedFile(file);
        setError(null);
        setUploadResult(null);
      }
    }
  };

  const handleUpload = async (): Promise<void> => {
    if (!selectedFile) {
      setError("Please select a file to upload");
      return;
    }

    setUploading(true);
    setError(null);

    try {
      // Upload file to the personal bucket
      // The uploadedByUserId is automatically set by the storage permissions
      const response = await nhost.storage.uploadFiles({
        "bucket-id": "personal",
        "file[]": [selectedFile],
      });

      const uploadedFile = response.body.processedFiles?.[0];
      if (uploadedFile === undefined) {
        throw new Error("Failed to upload file");
      }
      setUploadResult(uploadedFile);

      // Clear the form
      setSelectedFile(null);
      if (fileInputRef.current) {
        fileInputRef.current.value = "";
      }

      // Update the files list
      setFiles((prevFiles) => [uploadedFile, ...prevFiles]);

      await fetchFiles();

      // Clear success message after 3 seconds
      setTimeout(() => {
        setUploadResult(null);
      }, 3000);
    } catch (err: unknown) {
      const message = (err as Error).message || "An unknown error occurred";
      setError(`Failed to upload file: ${message}`);
    } finally {
      setUploading(false);
    }
  };

  const handleViewFile = async (
    fileId: string,
    fileName: string,
    mimeType: string,
  ): Promise<void> => {
    setViewingFile(fileId);

    try {
      // Get the file from storage
      const response = await nhost.storage.getFile(fileId);

      const url = URL.createObjectURL(response.body);

      // Handle different file types appropriately
      if (
        mimeType.startsWith("image/") ||
        mimeType === "application/pdf" ||
        mimeType.startsWith("text/") ||
        mimeType.startsWith("video/") ||
        mimeType.startsWith("audio/")
      ) {
        // Open viewable files in new tab
        window.open(url, "_blank");
      } else {
        // Download other file types
        const link = document.createElement("a");
        link.href = url;
        link.download = fileName;
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);

        // Show download confirmation
        const newWindow = window.open("", "_blank", "width=400,height=200");
        if (newWindow) {
          newWindow.document.documentElement.innerHTML = `
            <head>
              <title>File Download</title>
              <style>
                body { font-family: Arial, sans-serif; padding: 20px; text-align: center; }
              </style>
            </head>
            <body>
              <h3>Downloading: ${fileName}</h3>
              <p>Your download has started. You can close this window.</p>
            </body>
          `;
        }
      }
    } catch (err) {
      const message = (err as Error).message || "An unknown error occurred";
      setError(`Failed to view file: ${message}`);
      console.error("Error viewing file:", err);
    } finally {
      setViewingFile(null);
    }
  };

  const handleDeleteFile = async (fileId: string): Promise<void> => {
    if (!fileId || deleting) return;

    setDeleting(fileId);
    setError(null);
    setDeleteStatus(null);

    const fileToDelete = files.find((file) => file.id === fileId);
    const fileName = fileToDelete?.name || "File";

    try {
      // Delete file from storage
      // Permissions ensure users can only delete their own files
      await nhost.storage.deleteFile(fileId);

      setDeleteStatus({
        message: `${fileName} deleted successfully`,
        isError: false,
      });

      // Remove from local state
      setFiles(files.filter((file) => file.id !== fileId));

      await fetchFiles();

      // Clear success message after 3 seconds
      setTimeout(() => {
        setDeleteStatus(null);
      }, 3000);
    } catch (err) {
      const message = (err as Error).message || "An unknown error occurred";
      setDeleteStatus({
        message: `Failed to delete ${fileName}: ${message}`,
        isError: true,
      });
      console.error("Error deleting file:", err);
    } finally {
      setDeleting(null);
    }
  };

  return (
    <div className="container">
      <header className="page-header">
        <h1 className="page-title">File Upload</h1>
      </header>

      <div className="form-card">
        <h2 className="form-title">Upload a File</h2>

        <div className="field-group">
          <input
            type="file"
            ref={fileInputRef}
            onChange={handleFileChange}
            style={{
              position: "absolute",
              width: "1px",
              height: "1px",
              padding: 0,
              margin: "-1px",
              overflow: "hidden",
              clip: "rect(0,0,0,0)",
              border: 0,
            }}
            aria-hidden="true"
            tabIndex={-1}
          />
          <button
            type="button"
            className="btn btn-secondary file-upload-btn"
            onClick={() => fileInputRef.current?.click()}
          >
            <svg
              width="40"
              height="40"
              fill="none"
              viewBox="0 0 24 24"
              stroke="currentColor"
              role="img"
              aria-label="Upload file"
            >
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M7 16a4 4 0 01-.88-7.903A5 5 0 1115.9 6L16 6a5 5 0 011 9.9M15 13l-3-3m0 0l-3 3m3-3v12"
              />
            </svg>
            <p>Click to select a file</p>
            {selectedFile && (
              <p className="file-upload-info">
                {selectedFile.name} ({formatFileSize(selectedFile.size)})
              </p>
            )}
          </button>
        </div>

        {error && <div className="error-message">{error}</div>}

        {uploadResult && (
          <div className="success-message">File uploaded successfully!</div>
        )}

        <button
          type="button"
          onClick={handleUpload}
          disabled={!selectedFile || uploading}
          className="btn btn-primary"
          style={{ width: "100%" }}
        >
          {uploading ? "Uploading..." : "Upload File"}
        </button>
      </div>

      <div className="form-card">
        <h2 className="form-title">Your Files</h2>

        {deleteStatus && (
          <div
            className={
              deleteStatus.isError ? "error-message" : "success-message"
            }
          >
            {deleteStatus.message}
          </div>
        )}

        {isFetching ? (
          <div className="loading-container">
            <div className="loading-content">
              <div className="spinner"></div>
              <span className="loading-text">Loading files...</span>
            </div>
          </div>
        ) : files.length === 0 ? (
          <div className="empty-state">
            <svg
              className="empty-icon"
              fill="none"
              stroke="currentColor"
              viewBox="0 0 24 24"
              aria-hidden="true"
            >
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={1.5}
                d="M7 21h10a2 2 0 002-2V9.414a1 1 0 00-.293-.707l-5.414-5.414A1 1 0 0012.586 3H7a2 2 0 00-2 2v14a2 2 0 002 2z"
              />
            </svg>
            <h3 className="empty-title">No files yet</h3>
            <p className="empty-description">
              Upload your first file to get started!
            </p>
          </div>
        ) : (
          <div style={{ overflowX: "auto" }}>
            <table className="file-table">
              <thead>
                <tr>
                  <th>Name</th>
                  <th>Type</th>
                  <th>Size</th>
                  <th>Actions</th>
                </tr>
              </thead>
              <tbody>
                {files.map((file) => (
                  <tr key={file.id}>
                    <td className="file-name">{file.name}</td>
                    <td className="file-meta">{file.mimeType}</td>
                    <td className="file-meta">
                      {formatFileSize(file.size || 0)}
                    </td>
                    <td>
                      <div className="file-actions">
                        <button
                          type="button"
                          onClick={() =>
                            handleViewFile(
                              file.id || "unknown",
                              file.name || "unknown",
                              file.mimeType || "unknown",
                            )
                          }
                          disabled={viewingFile === file.id}
                          className="action-btn action-btn-edit"
                          title="View File"
                        >
                          {viewingFile === file.id ? "⏳" : "👁️"}
                        </button>
                        <button
                          type="button"
                          onClick={() => handleDeleteFile(file.id || "unknown")}
                          disabled={deleting === file.id}
                          className="action-btn action-btn-delete"
                          title="Delete File"
                        >
                          {deleting === file.id ? "⏳" : "🗑️"}
                        </button>
                      </div>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        )}
      </div>
    </div>
  );
}

Update Application Routes

Add the uploads page to your application routing.

import {
  createBrowserRouter,
  createRoutesFromElements,
  Navigate,
  Outlet,
  Route,
  RouterProvider,
} from "react-router-dom";
import Navigation from "./components/Navigation";
import ProtectedRoute from "./components/ProtectedRoute";
import { AuthProvider } from "./lib/nhost/AuthProvider";
import Files from "./pages/Files";
import Home from "./pages/Home";
import Profile from "./pages/Profile";
import SignIn from "./pages/SignIn";
import SignUp from "./pages/SignUp";
import Todos from "./pages/Todos";
import Verify from "./pages/Verify";

// Root layout component to wrap all routes
const RootLayout = () => {
  return (
    <>
      <Navigation />
      <div className="app-content">
        <Outlet />
      </div>
    </>
  );
};

// Create router with routes
const router = createBrowserRouter(
  createRoutesFromElements(
    <Route element={<RootLayout />}>
      <Route index element={<Home />} />
      <Route path="signin" element={<SignIn />} />
      <Route path="signup" element={<SignUp />} />
      <Route path="verify" element={<Verify />} />
      <Route element={<ProtectedRoute />}>
        <Route path="profile" element={<Profile />} />
        <Route path="todos" element={<Todos />} />
        <Route path="files" element={<Files />} />
      </Route>
      <Route path="*" element={<Navigate to="/" />} />
    </Route>,
  ),
);

function App() {
  return (
    <AuthProvider>
      <RouterProvider router={router} />
    </AuthProvider>
  );
}

export default App;

Update Navigation Links

Add a link to the uploads page in the navigation bar.

import { Link, useNavigate } from "react-router-dom";
import { useAuth } from "../lib/nhost/AuthProvider";

export default function Navigation() {
  const { isAuthenticated, session, nhost } = useAuth();
  const navigate = useNavigate();

  const handleSignOut = async () => {
    try {
      if (session) {
        await nhost.auth.signOut({
          refreshToken: session.refreshToken,
        });
      }
      navigate("/");
    } catch (err: unknown) {
      const message = err instanceof Error ? err.message : String(err);
      console.error("Error signing out:", message);
    }
  };

  return (
    <nav className="navigation">
      <div className="nav-container">
        <Link to="/" className="nav-logo">
          Nhost React Demo
        </Link>

        <div className="nav-links">
          <Link to="/" className="nav-link">
            Home
          </Link>

          {isAuthenticated ? (
            <>
              <Link to="/todos" className="nav-link">
                Todos
              </Link>
              <Link to="/files" className="nav-link">
                Files
              </Link>
              <Link to="/profile" className="nav-link">
                Profile
              </Link>
              <button
                type="button"
                onClick={handleSignOut}
                className="nav-link nav-button"
              >
                Sign Out
              </button>
            </>
          ) : (
            <>
              <Link to="/signin" className="nav-link">
                Sign In
              </Link>
              <Link to="/signup" className="nav-link">
                Sign Up
              </Link>
            </>
          )}
        </div>
      </div>
    </nav>
  );
}

Test Your File Upload System

Run your application and test all the functionality:

npm run dev

Things to try out:

1. Try signing in and out and see how the file upload page is only accessible when signed in.
2. Upload different types of files (images, documents, etc.)
3. View and delete files
4. Sign in with another account and verify you cannot see files from the first account

Key Features Implemented

Storage Bucket

Dedicated personal storage bucket with proper configuration for user file isolation.

File Upload Interface

User-friendly upload interface with file selection, preview, and progress feedback.

File Management

Complete file listing with metadata, viewing capabilities, and deletion functionality.

File Type Handling

Intelligent handling of different file types with appropriate viewing/download behavior.

Error Handling

Comprehensive error handling with user-friendly messages for upload and management operations.