kx-playback

KX PlayBack Component

Also read kx-dashboard-core for: envelope, screen/widget wrapper, data sources, ViewState, binding patterns, actions, notifications, and the pre-flight checklist.

⚠️ PlayBack-Specific Hazards

1. key is "PlayBack" — not "BasicComponents". This is the only component with a dedicated top-level key outside BasicComponents.
2. Selected must be a ViewState binding — it receives the current playback position and drives all components that react to playback. Omitting it means nothing updates during playback.
3. SelectedColumn must match a column in the data source — it is the column whose value is published to Selected at each playback step. If left blank, nothing is published.
4. TimeColumn is only relevant in Mode: "Time" — in Mode: "Event" it is unused. In Mode: "Time", TimeColumn specifies the timestamp column used to derive playback timing.
5. Mode: "Event" steps through data rows sequentially — IntervalTime controls the delay in seconds between steps. Mode: "Time" uses the values in TimeColumn to derive real elapsed time between steps.
6. Playing: 0 is the stopped state — do not set Playing to a non-zero value in the initial JSON; the component manages this field at runtime.
7. **Data source must be sorted by SelectedColumn using `col xasc ** — PlayBack steps through rows in the order they arrive from the data source; unsorted data produces non-sequential playback. Always prepend `<column> xasc to the query, e.g. `Date xasc select distinct Date from SPX.

PLAYBACK

key: "PlayBack" · definitionId: "47" · version: "4.7.7"

A time-series playback controller. Steps through a data source row by row (Event mode) or by time (Time mode), publishing the current position to a ViewState that other components subscribe to.

Basics

{
  "Name": "",
  "Data": { "_dashboardsType": "data", "value": "<timeSeriesDataSource>" },
  "Selected": { "_dashboardsType": "viewstate", "value": "<currentPositionViewState>" },
  "SelectedColumn": "<value-column>",
  "TimeColumn": "<timestamp-column>",
  "Mode": "Event",
  "Speed": "1x",
  "Playing": 0,
  "MaxOverallTime": 60,
  "IntervalTime": 1,
  "speedControl": false,
  "multiStateControl": false,
  "ForcePause": false,
  "DisplayWarning": false
}