Widgets

The Widget Module (apps/backend/modules/widget) is responsible for defining data visualizations and connecting them to data sources (SQL Queries or Workflows).

Architecture

The module has two distinct execution modes handled by widget.service.js:

1. Query Mode: Direct execution of SQL queries via dataQueryService.
2. Workflow Mode: Triggering a workflow via workflowService and streaming results.

Real-time Data Bridge

The widgetWorkflowBridge.js is a critical component that enables real-time charts. It acts as a middleware between the Workflow Orchestrator and the Frontend Widgets.

Bridge Data Flow

Key Functions

registerWidget(widgetID, instanceID, socket, metadata)

Maps a connected frontend widget to a running workflow instance. Stores metadata (like which fields to plot) in memory.

processContextForWidget(context, widgetConfig)

Transforms raw workflow variables (e.g. [ { x: 1, y: 10 }, { x: 2, y: 20 } ]) into the specific format required by the widget type (e.g. Bar Chart needs separate label/value arrays). This transformation happens on the Server Side to reduce frontend payload size.

Widget Service API

getWidgetDataByID

Params: { widgetID, executionMode: 'ASYNC' | 'SYNC' }

• Async Mode (Default):
  1. Triggers workflowService.executeWorkflow.
  2. Returns { status: "PENDING", instanceID: "..." }.
  3. Frontend subscribes to instanceID via Socket.
• Sync Mode:
  1. Triggers workflow.
  2. Polles internal status until COMPLETED.
  3. Returns full payload { status: "COMPLETED", data: [...] }.