The link (channel) name. Link names can be custom names, specified when a cross-source link is created, or names in the format <source-name>.<field-name>, automatically generated for every field in a data source for same-source links.

The link name is defined when you define a cross-source link. See Define Cross-Source Links. It is published for use by a dashboard as a cross-visual filter. See Publish a Link. The link name represents the channel into which the message should be published. It is typically called a topic in standard publish/subscribe systems.

There is a one-to-one relationship between cross-source link names and your data fields. You cannot use the same link name for multiple data fields. In addition, you cannot create multiple cross-source links for the same data field.

Type: string

The message sent with the link. The message published can either be an arbitrary object or null. An object published to a link channel is not restricted to any particular structure but a Composer dashboard only recognizes messages in the structure described in Published Cross-Visual JavaScript Message Structure.

Publishing a null message can clear the last published message from the channel. If the last published message's publisherId matches the null message's publisherId, the last message is removed from the channel and subscribers receive a null message. If the publisherId of the last published message on the channel does not match the null message's publisherId, nothing happens.

The most recently published message on each channel is stored and sent to new subscribers at the time of subscription.

Type: object or null