The data can be obtained from some type of feed, perhaps provided by some external API or it can be from some other application communicating using Diffusion™ protocols. This is entirely up to the publisher but Diffusion does offer some mechanisms.

Control clients

A publisher can receive input from a control client.

Control clients can use the TopicUpdateControl feature to publish messages to topics. Where such topics have topic data the topic state is automatically updated and deltas are published to subscribed clients. Where topics do not have topic data, published messages are forwarded to subscribed clients (that is, it is assumed that the control client maintains the data state).

Control clients can also send messages to specific clients and these are forwarded to the clients automatically.