Widget Functionality

What it does

Visualizes recent values for a set of Tango attributes either as line traces or as a heatmap. It can subscribe to live updates or periodically fetch windows of HDB++ history.

Expected data

  • attributes: fully-qualified attribute names.

GraphQL operations

  • Live stream (subscription):

    • subscription tangoAttributes(fullNames: [String!]!) { device attribute value timestamp }

  • History snapshots (query): see src/graphql/operations.ts for the exact query returning historical ranges with optional downsampling.

Notes:

  • When useHeatmap = true, Y = attributes, X = time, color = value.

  • heatmapConnectGaps can forward-fill onto an even grid to keep the heatmap continuous, or leave holes to highlight missing timestamps.

  • appendInterval throttles UI updates; backend streams are still consumed.