Property Hub

The Property Hub block enables you to handle related properties as a group. To use a property hub in a dataflow, add the block and, using the + key, add the required properties. The Property Hub block supports properties that are specified in JSON format.

For information on using dataflow blocks, see Dataflow.

The following properties of the Property Hub block can take input and give output.

• invoke (trigger)
• autoRun (bool)
• syncPropertyList (trigger)
• hubMode (enum)
• hubInstance
• jsonInput (string)
• outputAll (bool)
• custom properties

** invoke ** triggers the block. In main mode it recomputes jsonOutput and hubInstance; in readWrite or writeOnly mode it writes all of the custom property values to the main hub.

** autoRun ** specifies whether the block runs automatically each time one of its custom properties changes. The Property Hub block from the palette has autoRun set to TRUE. This property is not shown on the block.

** syncPropertyList ** copies the list of custom properties from the main hub that is bound to hubInstance. This property is not shown on the block.

** hubMode ** controls the block behavior. The default is main. (Older dataflows that used "master" and "slave" are converted to main and readWrite.)

• main – This block holds the property values. It outputs itself through hubInstance; bind that output to the hubInstance of other Property Hub or Property Hub Modifier blocks.
• readWrite – Reads values from the main hub bound to hubInstance, and writes changed values back to it.
• readOnly – Reads values from the main hub, but does not write changes back.
• writeOnly – Writes changed values to the main hub, but is not updated by it.

** hubInstance ** In main mode, outputs a reference to this hub. In the other modes, bind it to the hubInstance of the main hub.

** jsonInput ** In main mode, sets the custom properties from a JSON object (or a JSON string). Only keys that match existing custom properties are used. This property is not shown on the block.

** outputAll** (bool) specifies whether complex objects (such as tables) are included in jsonOutput. For efficiency, such objects are not included by default.

custom properties are the properties that you add with the + button. They hold the values shared through the hub.

The following property of the Property Hub block can give output but cannot take input.

• jsonOutput (string)

** jsonOutput ** returns the custom property values as a JSON string. In readWrite and readOnly mode it returns the JSON of the main hub. This property is not shown on the block.

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