File Explorer / Media Gallery

A file explorer or media gallery in a mobile app allows users to select their own files, photos, or videos from the device’s storage—for example, to upload, view, or edit them. Users can access their photo gallery, downloads, or saved documents directly from within the app. Such features are now standard in social media apps, cloud storage services, support forms, and e-commerce applications.

🔧 Technical Explanation

In Expo-based React Native apps, access to local files and media is implemented via system-level interfaces that Expo makes readily available:

• expo-media-library
• → Access to images, videos, and albums
• expo-document-picker
• → Opens a native dialog for file selection (e.g., PDF, DOCX, CSV)
• expo-image-picker
• → Selects images/videos from the gallery or camera These libraries are OTA-compatible and work with both the Expo Go app and in your own build using EAS (Expo Application Services). The first time the app is accessed, it automatically requests the required permissions (e.g., media access) using MediaLibrary.requestPermissionsAsync() or ImagePicker.requestMediaLibraryPermissionsAsync().

💡 Possible Uses

• Upload a profile picture or avatar
• Select product images during the checkout process
• Upload a screenshot for support
• Attach PDFs or documents to forms
• Display an image gallery in creative or messaging apps
• Enable multiple selection for media uploads

❓ Important Questions and Answers About the File Explorer / Media Gallery

How does my Expo app access the gallery? Using expo-media-library or expo-image-picker. These libraries display a native file selector to the user and return the paths to the selected media. Does the user have to grant permissions? Yes. The first time the app accesses the gallery, it automatically requests media access. The gallery cannot be displayed without consent. What file types can I select? With expo-document-picker, you can select PDF, DOCX, TXT, CSV, images, ZIPs, and more. You can specifically limit the allowed types. Can multiple files be selected at the same time? Yes—expo-document-picker supports multi-select, provided the platform allows it. For images, a separate selection UI may be necessary. Are images and videos stored locally or externally? The APIs provide you with local URIs that can be displayed or processed directly within the app. Uploading to a server is handled separately via fetch() or a cloud API.