Breaking change with ImageProvider.load in Flutter 1.10

The Flutter team made a breaking change with the ImageProvider in Flutter 1.10.15 (currently Master channel only).

If you are experiencing one of the following errors upgrade to 2.0.0-rc.

The method 'ScaledFileImage.load' has fewer positional arguments than those of overridden method 'ImageProvider.load'
The method 'CachedNetworkImageProvider.load' has fewer positional arguments than those of overridden method 'ImageProvider.load'

Cached network image

Widget now uses builders for the placeholder and error widget and uses sqflite for cache management. See the docs for more information.

pub package Donate

A flutter library to show images from the internet and keep them in the cache directory.

How to use

The CachedNetworkImage can be used directly or through the ImageProvider.

CachedNetworkImage(
        imageUrl: "http://via.placeholder.com/350x150",
        placeholder: (context, url) => CircularProgressIndicator(),
        errorWidget: (context, url, error) => Icon(Icons.error),
     ),
Image(image: CachedNetworkImageProvider(url))

When you want to have both the placeholder functionality and want to get the imageprovider to use in another widget you can provide an imageBuilder:

CachedNetworkImage(
  imageUrl: "http://via.placeholder.com/200x150",
  imageBuilder: (context, imageProvider) => Container(
    decoration: BoxDecoration(
      image: DecorationImage(
          image: imageProvider,
          fit: BoxFit.cover,
          colorFilter:
              ColorFilter.mode(Colors.red, BlendMode.colorBurn)),
    ),
  ),
  placeholder: (context, url) => CircularProgressIndicator(),
  errorWidget: (context, url, error) => Icon(Icons.error),
),

How it works

The cached network images stores and retrieves files using the flutter_cache_manager.

Libraries

cached_network_image

Dart

VM

dart:ffi
Foreign Function Interface for interoperability with the C programming language. [...]

Web

dart:html
HTML elements and other resources for web-based applications that need to interact with the browser and the DOM (Document Object Model). [...]
dart:js
Low-level support for interoperating with JavaScript. [...]
dart:js_util
Utility methods to efficiently manipulate typed JSInterop objects in cases where the name to call is not known at runtime. You should only use these methods when the same effect cannot be achieved with @JS annotations. These methods would be extension methods on JSObject if Dart supported extension methods.