JsonSchema (Json Schema)
This component defines the schema, which includes the resulting output, configuration and queries properties, JSON entities,
and actions.
Figure 28. JsonSchema properties
You add a schema to a station by dragging a JsonSchema from the palette to the Config folder in the Nav tree. From there, to access schema properties, expand the Config folder and double-click the schema.
| Property | Value | Description |
|---|---|---|
| Output | container | Contains the generated JSON string. |
| Enabled | true (default) or false |
Activates (true) and deactivates (false) use of the object (network, device, point, component, table, schedule, descriptor, etc.).
|
| Status | read-only | Indicates if the network, device, point or component is active or inactive. |
| Fault Cause | read-only | Indicates the reason why a system object (network, device, component, extension, etc.) is not working properly (in fault). This property is empty unless a fault exists. |
| Last Updated | read-only | Reports when the schema was updated last. |
| Config | folder | Contains properties for customizing the schema. |
| Queries | folder | Contains the query ords. |
root
This container holds JSON entities: objects, arrays, properties and bound properties.
Figure 29. root Json Schema Object
A separate topic documents each of type of object, array and property.
Buttons
These functions are available when you click a button and name to the right of the Output property on the schema Property Sheet.
Figure 30. JSON Schema actions on the right side
- Generate requests a rebuild and update of schema output. For relative schemata, this evaluates the
Base Queryand publishes results. - Copy copies the selected JSON to the clipboard.
- Clear Output sets the Out slot of this component to an empty string.
- Output History displays a history of the most recent schema output values in a new tab. This information is useful to confirm output contents if the schema changes rapidly due to subscribed points, and to have timestamps show how frequently it changes.
- Metrics reports information used to size and provision capacity as well as debug performance problems.
- Indented Display toggles the
Outputdisplay between the underlying JSON string (which does not have extraneous whitespace) and a syntax highlighted and indented version that is easier to understand. It defaults to the latter.
Actions
These actions are available when you right-click the JsonSchema node in the Nav tree.
- Generate Json executes the JSON code.
- Force Generate Json forces the generate action regardless of the current tuning settings.
- Clear Cache discards the last known values of bindings and cached query results.
- Clear Output sets the Out slot of this component to an empty string.
- Execute Queries forces an immediate execution of all the schemas queries. You can link this action to some appropriate logic to trigger execution when needed.
- Unregister And Unsubscribe All (relative schema only) unsubscribes the registration from any base items that the relative schema monitors for updates and removes cloud registration from all export-marked entities in the station.