Need to parallelise async operation using stream in dart - flutter

Question

Problem: I am building an application on an RSS feed reader.
In a feed:
There are various items and each item is an article which has a URL.
Each URL has open graph metadata which needs to be fetched and takes time.
As soon as URL open graphs metadata is loaded it needs to be shown in the list on the UI.
Now I want to run 2 and 3 in parallel, am doing this in the code for now:
Stream<News> _getNewsRssFeed(Categories selectedCategory) async* {
try {
final rssUrl = _getRssUrl(selectedCategory);
RssFeed feed = await _getRssFeed(rssUrl);
if (feed.items != null) {
for (int itemIndex = 0; itemIndex < feed.items!.length; itemIndex++) {
final item = feed.items![itemIndex];
try {
Future<News> news = _processRssFeedItem(item, feed);
news.then((value){
yield value; // This is not working
});
} catch (error) {
print("Error while parsing ${item.link} error = $error");
}
}
}
} catch (error) {
print("Error while parsing RssFeed url $error");
}
}
The problematic line I have commented in above code, can you please let me know what is the best way here?

Answer 1

Basically, news.then returns Future and you are not awaiting for the result to be available.
You can change it by changing code to following
try {
final value = await _processRssFeedItem(item, feed);
yield value;
} catch (error) {
print("Error while parsing ${item.link} error = $error");
}