TwitterKit filter timeline but inversely? - twitter

Question

I'm displaying a twitter timeline in my app via Fabric TwitterKit.
I want to filter the timeline by showing only tweets # a specific user. I've read the documentation from here on how to filter tweets in the timeline. Unfortunately for me, the function they provide will exclude any tweet that contains the specified keyword/s in the timeline.
The behavior I'm looking for is one that will include only the tweets that contain the specified keyword/s in the timeline.
Is this possible to do with TwitterKit? I've been searching for an inverse filter for this but there seems to be none.

Answer 1

First of all it is not clear what is your source timeline. Have you considered using TWTRSearchTimelineDataSource and configuring Search API query? The Search API supports compound queries with some logical functions, so you might be able to create a query that will cover all your needs.
Note: given the link you provided in your question I assume your target platform is iOS. You can apply similar solution for Android.
If the Search API is not powerful enough for you, your other choice is to do some client-side filtering. I was not able to find iOS source code but some version of Twitter Kit for Android is available at GitHub. If you look at BasicTimelineFilter and
FilterTimelineDelegate, you can see that in Android filtering is actually performed on the client side. So you can do the same with any custom filtering in your iOS application. All you need is create a wrapper class that will implement TWTRTimelineDataSource protocol and do your custom filtering. Here is some sketch of how the code might look like in Objective-C (you can do the same in Swift of course):
Note: beware of bugs, I haven't even compiled this code
.h file
typedef BOOL (^SOTweetFilter)(TWTRTweet * tweet);
#interface SOFilteredTimelineDataSourceWrapper : NSObject<TWTRTimelineDataSource>
- (instancetype)initWithDataSource:(id<TWTRTimelineDataSource>)dataSource filter:(SOTweetFilter)filter;
#end
.m file
#implementation SOFilteredTimelineDataSourceWrapper
#property (nonatomic, strong, readwrite) id<TWTRTimelineDataSource> wrapped;
#property (nonatomic, copy) SOTweetFilter filter;
- (instancetype)initWithDataSource:(id<TWTRTimelineDataSource>)dataSource filter:(SOTweetFilter)filter {
if(!(self = [super init])) return self;
self.wrapped = dataSource;
self.filter = filter;
return self;
}
- (void)loadPreviousTweetsBeforePosition:(nullable NSString *)position completion:(TWTRLoadTimelineCompletion)completion {
// typedef void (^TWTRLoadTimelineCompletion)(NSArray<TWTRTweet *> * _Nullable tweets, TWTRTimelineCursor * _Nullable cursor, NSError * _Nullable error);
[wrapped loadPreviousTweetsBeforePosition:position completion:^(NSArray<TWTRTweet *> * _Nullable tweets, TWTRTimelineCursor * _Nullable cursor, NSError * _Nullable error) {
if(error) {
// forward error
completion(tweets, cursor, error);
}
else {
// filter results
NSArray* filtered = [tweets filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:(id evaluatedObject, NSDictionary<NSString *,id> *bindings) {
return self.filter(evaluatedObject);
}]];
completion(filtered, cursor, error);
}
}];
}
// delegate all properties to the wrapped
- (TWTRTimelineType)timelineType {
return wrapped.timelineType;
}
-(TWTRTimelineFilter *)timelineFilter {
return wrapped.timelineFilter;
}
-(void)setTimelineFilter:(TWTRTimelineFilter *)timelineFilter {
wrapped.timelineFilter = timelineFilter;
}
- (TWTRAPIClient *)APIClient{
return wrapped.APIClient;
}
- (void)setAPIClient:(TWTRAPIClient *)APIClient{
wrapped.APIClient = APIClient;
}
#end
The main idea is that you intercept loadPreviousTweetsBeforePosition:completion: call and add your additional processing before calling the original completion callback. Using such SOFilteredTimelineDataSourceWrapper you can wrap any other TWTRTimelineDataSource and do any filtering you want analyzing TWTRTweet.text. For mentions (i.e. handle-based) filtering you might want to take a look at Android implementation of normalizeHandle.