uri_content

Get Uint8List content from a Uri in Flutter.

This package reads content directly from the original source and streams bytes in memory. It does not create temporary files while fetching content.

Supported URI schemes

• data:
• file:
• http:
• https:
• content: (Android only)

Usage styles

You can use uri_content in two ways:

1. Uri extension methods (getContent() / getContentOrNull()).
2. A UriContent instance (recommended for testability, injection, custom headers, and Android content: buffer tuning).

Quick start

import 'dart:typed_data';
import 'package:uri_content/uri_content.dart';

Future<Uint8List> loadBytes() async {
  final uri = Uri.parse('https://example.com/file.bin');
  try {
    return await uri.getContent(); // extension on Uri
  } catch (e) {
    // getContent() can throw when content can't be retrieved.
    rethrow;
  }
}

If you prefer nullable behavior on failure:

final bytesOrNull = await Uri.parse('https://example.com/file.bin').getContentOrNull();

Using UriContent directly

Use UriContent when you want dependency injection/mocking, custom headers, a custom HttpClient, or control over Android content: read buffer size.

import 'dart:io';
import 'package:uri_content/uri_content.dart';

final uriContent = UriContent(
  defaultHttpHeaders: {'Authorization': 'Bearer <token>'},
  httpClient: HttpClient(),
);

final bytes = await uriContent.from(
  Uri.parse('https://example.com/private.bin'),
  httpHeaders: {'X-Request-Id': 'abc-123'},
);

Streaming large content

from() returns all bytes in a single Uint8List. For large files, prefer getContentStream() to process chunks and reduce memory usage. Fetching very large content with from() may use too much memory and can crash your app.

import 'package:uri_content/uri_content.dart';

final uri = Uri.parse('https://example.com/large-file.zip');
final stream = UriContent().getContentStream(uri);

await for (final chunk in stream) {
  // process/save chunk
}

If you stop early, cancel the stream subscription. Always consume the stream to completion or cancel it to avoid resource leaks.

For Android content: URIs, bufferSize controls chunk size (default: 5 MB). Larger values can considerably increase performance, while smaller values reduce memory consumption:

final stream = UriContent().getContentStream(
  Uri.parse('content://...'),
  bufferSize: 1024 * 1024, // 1 MB
);

Utility methods

final uriContent = UriContent();
final uri = Uri.parse('https://example.com/file.bin');

final canFetch = await uriContent.canFetchContent(uri);
final length = await uriContent.getContentLength(uri); // may be null
final lengthOrNull = await uriContent.getContentLengthOrNull(uri);

• canFetchContent() checks whether content can be fetched (for example, file existence for file: URIs and reachability for http/https URIs).
• getContentLength() uses metadata and may be inaccurate; it can throw if content is not reachable; it returns null when length is unavailable.
• getContentLengthOrNull() returns null on errors, but null is ambiguous (unreachable content vs unavailable length).

Errors

• from() and getContent() throw when content cannot be retrieved.
• fromOrNull() and getContentOrNull() return null on errors.
• Unsupported schemes throw UnsupportedSchemeError.