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Message Bus#

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This task acts over the MessageBus communication layer. It makes possible to publish a message, send a message with a request for a reply and subscribe to a certain subject.

Warning

This task is currently deprecated and will be removed in future versions.

Inputs#

Name Data Type IsTrigger Description
activate boolean Yes Activates whatever the action type is

Outputs#

Name Data Type Description
success Boolean true True value emitted when the action is successfully performed
error Error Error that occurred during the processing of this task or a timeout occurs when a SendRequest is waiting for reply

Different Inputs/Outputs#

This task can have different inputs/outputs, depending on the selected type in the options.

Action Type Publish#

1561732918756

Inputs#

Name Data Type IsTrigger Description
subject String No Subject of the message to be published
message any Yes Message to publish

Action Type SendRequest#

1561733291987

Inputs#

Name Data Type IsTrigger Description
subject String No Subject of the message to be sent
message any Yes Message to send

Outputs#

Name Data Type Description
data Object Emitted when a SendRequest receives a reply message

Action Type Subscribe#

1561733468540

Inputs#

Name Data Type IsTrigger Description
subject String Yes Subject to be listening to. When a different subject is received, a new subscription is performed
reply Object No Message input to reply to a SendRequest

Outputs#

Name Data Type Description
subscribedSubject String To output the subject received from a Publish/SendRequest
data Object Emitted when a message is received from a Publish/SendRequest

Settings#

Name Data Type PossibleValue Default Description
Action Enum Publish
SendRequest
Subscribe		 Publish Type of action to be performed by the task.
Subject String Subject of the message to publish or subscribe
Timeout Integer 60000 Number of milliseconds to wait for a reply message. Not applicable to action type Publish
Auto Activate Boolean true For the action type Subscribe, if this flag is set to true, the task will automatically subscribe to the subject

1561733783455

Behavior#

This task has three different modes of operation.

Publish#

This mode is activated when it receives a message or a true value in the activate input.

Upon activation, a message is published to a given subject (Fire and Forget), and the success output emits its respective value.

SendRequest#

This mode is activated when it receives a message or a true value in the activate input.

Upon activation, a message with a request for a reply is sent.

If a reply message is received, during the time interval defined in the settings, both data and success outputs emit their respective values. Otherwise, if a reply message is not received in that time interval, a timeout will occur, and an error will be emitted by the error output.

Subscribe#

The Subscribe action is activated by one of the following conditions:

  • Auto Activate setting is set to true
  • activate input is fed with a true Boolean value (or compatible, like 1, true, t, yes, y)
  • subject input is fed with a different subject from the one already subscribed

Upon activation, when a message is published to the subscribed subject, the data, subscribedSubject and success outputs will emit their respective values.

if activate input receives a false Boolean value, and there is an active subscription it will be immediately deactivated.

Note

When a certain subscription receives a message from a SendRequest, it will wait for the reply input to be fed with the reply message (the time to wait is defined in the timeout setting). If no message is received during that time interval, no reply will be sent.

Remarks#

This task uses a specific structure of context-based data called zone. More information on this topic can be read in the Zones page.