We try to save, load and display images from the network, when the user is offline
void saveImage(String imageUrl, String imageName) async{
File file = File(await getImagePath(mediaName));
ByteData questionMediaData = await NetworkAssetBundle(Uri.parse(imageUrl)).load("");
file.writeAsString(questionMediaData.buffer.asUint8List());
}
Future<Uint8List> loadImage(String mediaName) async{
String path = imageUrl + mediaName;
if(await File(path).exists()){
File file = File(await getImagePath(path));
return await file.readAsString();
}
return null;
}
Future<String> getImagePath(String imageName) async {
Directory appDocumentsDirectory = await getApplicationDocumentsDirectory();
String appDocumentsPath = appDocumentsDirectory.path;
String filePath = '$appDocumentsPath/$imageName';
return filePath;
}
We have an ImageProvider-Class:
class OurImageProvider {
static Widget getImage(String imageName, {BoxFit fit = BoxFit.cover, double width, double height, ImageType imageType = ImageType.standard}) {
if(!hasText(imageName)){
if(imageType == ImageType.content)
return Image(
image: AssetImage('assets/dummy_images/catalog_dummy.jpg'),
fit: BoxFit.cover,
width: width,
height: height,
);
else
return Container();
}
return Image.network(imageName, fit: fit, width: width, height: height,
errorBuilder: (BuildContext context, Object exception, StackTrace stackTrace) {
return getAltImage(imageName, width, height, fit);
},
);
}
static Image getDummyImage(double width, double height, BoxFit fit) => Image(image: AssetImage('assets/dummy_images/dummy.jpg'), width: width, height: height, fit: fit);
static getAltImage(String imageName, double width, double height, BoxFit fit) async{
var localImage = await LocalStorage.instance.loadImage(imageName);
if(localImage != null){
return Image.memory(localImage, fit: BoxFit.cover,width: width, height: height, errorBuilder: (BuildContext context, Object exception, StackTrace stackTrace) {
return getDummyImage(width, height, fit);
},);
}
return getDummyImage(width, height, fit);
}
}
Our Problem is now that I don't find a way to fix this class as getAltImage has to be async and I cannot get getImage working to be usable as a child in the build method...
Try to add await:
return Image.memory(await localImage,...);