Extractors are KBC components used for importing data from external sources into KBC.
Typically, extractors connect to APIs external services, like Facebook, Youtube, Gmail and so on. They can also connect directly to an arbitrary database.
Extractors can be grouped by their primary purpose:
For a definitive list of usable extractors, see your project Extractors section or the public list of components.
Even though extractors are generally designed for automated and repeated data collection, they can be triggered manually at any time.
As bringing data into KBC is the main purpose of an extractor, go the path of least resistance: Get your data in first, and then convert it to what you want it to look like. To give an example, when connecting to existing information systems, do not modify the data in them. Such data conversion can prove to be difficult and expensive. Extract what you need and shape it in KBC.
Some extractors have limits inherent to their sources. Unfortunately, there is not much we can do about it. For example, the Twitter extractor will not let you access the history of a particular tweet account beyond a certain point because of the limitations of Twitter API.