[Feature request] Option to pass exclude item IDs

[generalomosco]

Currently my approach to avoid querying duplicated items.

First

This is be ran every time i called GetRecommend or fetch posts directly from database

		for _, item := range postsResponses {
			//Feedback is been sent immediately after each query to prevent fetching same posts on next query, the "read" will later be updated to "watched" when watched
			
			postsFeedbacks = append(postsFeedbacks, gClient.Feedback{
				FeedbackType: "read",
				UserId:       utilities.ToStr_fromInt(user_id),
				ItemId:       utilities.ToStr_fromInt(item.Data.ID),
				Value:        0,
				Timestamp:    appInst.Util.Time.GetNow(),
			})
		}
	

	if len(postsFeedbacks) != 0 {
		appInst.Recommender.GorseClient.InsertFeedback(context.Background(), postsFeedbacks)
	}

Then secondly

//Delete all "read" feedback upto an 30 minutes in database in task job
	var feedbacks []RecommenderFeedback
	db.Table("feedback").Select("user_id, item_id").Where("feedback_type = ? AND updated <= NOW() - INTERVAL ? MINUTE", "read", 30).Limit(10000).Scan(&feedbacks)
	for _, f := range feedbacks {
		self.instance.Task.Usecase.Session.App.Recommender.GorseClient.DeleteFeedback(context.Background(), "read", f.UserID, f.ItemID)
	}

This approve is not that nice, better approach should be passing exclude item IDs too to GetRecommend api

[zhangzhenghao]

You don't need to insert read feedback in the application after every recommendation request. Gorse can write it back automatically:

GET /api/recommend/{user-id}?n=10&write-back-type=read

Make sure read is configured as a read feedback type:

[recommend.data_source]
read_feedback_types = ["read"]

The returned items are then stored as read feedback and will be excluded from subsequent recommendations for that user.

write-back-delay is not a TTL. For example, write-back-delay=30m writes the feedback with a timestamp 30 minutes in the future, so it does not exclude the item until that time. It does not make the feedback expire after 30 minutes.

If the items should become eligible again after 30 minutes, automatic expiration of read feedback is currently not supported. The read feedback still needs to be deleted after 30 minutes, preferably through the feedback API rather than by modifying Gorse's database directly:

DELETE /api/feedback/read/{user-id}/{item-id}

So write-back removes the manual insertion step, but a scheduled deletion is still required for a 30-minute exclusion window. Passing an explicit per-request exclusion list would be a separate feature.

[generalomosco]

Meaning write-back-delay is not working currently because i'm trying /api/recommend/6?n=2&offset=0&write-back-delay=1m&write-back-type=read the write-back-delay=1m is still not fetching the read write-back-type feedback items even when expired already