Topics

In Diffusion® Cloud, a topic is a channel through which data is distributed to clients.
Topics provide a logical link between publishing clients and subscribing clients.

Data types

Diffusion® Cloud topics are based on 'data types'. Data sent through topics must match the data type of the topic. You can publish data to these topics, and the data is streamed to subscribing clients.
The possible data types are:

  • JSON

  • Binary

  • String

  • Int64

  • Double

  • RecordV2

Time series topics

Time Series topics provide additional capabilities such as, storing a sequence of events. They are useful for collaborative applications such as chat rooms. Multiple users can concurrently update a time series topic.

Topic selectors

A client can reference a topic by its topic path.
Alternatively, you can also use topic selectors to access all the topics that match a regex or topic tree expression.

For example, you might want your client to subscribe to every topic under the /foo/bar path.

Since you cannot know ahead of time which topics will exist there; instead of specifying every topic path, you can use a topic selector.

Topic selector foo bar foo/bar foo/baz foo/bar/baz/bing

foo

tick

cross

cross

cross

cross

?foo/

cross

cross

tick

tick

tick

?foo//

tick

tick

tick

tick

tick

?foo/.*

cross

tick

tick

tick

cross

?foo/bar

cross

cross

tick

cross

cross

?foo/bar/

cross

cross

cross

cross

tick