List Dataset Node

Overview

The List Dataset node publishes the list of available datasets from the connected Firebase configuration. It automatically sends messages when the flow starts and whenever the dataset list changes, making it ideal for dynamic UI components, dashboard displays, and dataset selection workflows.

Key Features

Auto-emit on startup: Sends dataset list when flow starts
Real-time updates: Emits when datasets change in Firebase
Manual trigger: Can be triggered via input message
Tag statistics: Includes image counts per tag
Dropdown options: Provides formatted options for UI selectors
Connection monitoring: Visual status indicators for Firebase connection
Sorted output: Datasets alphabetically sorted by name

Use Cases

Populate dropdown menus for dataset selection
Display dashboard statistics of available datasets
Monitor dataset updates in real-time
Trigger workflows when new datasets are added
Generate reports on dataset inventory

Configuration

Properties

Output Field

Type: Message property path
Default: payload
Required: Yes
Description: Where the dataset array will be stored in the message

Firebase Config

Type: Node reference (firebase-config)
Required: Yes
Description: Reference to firebase-config node for authentication

Input

Manual Trigger

Send any message to manually request the current dataset list:

javascript

msg.payload = true;  // Or any value
return msg;

Behavior:

Only works if Firebase is connected
Emits dataset list with reason: "manual"
Useful for refresh buttons or periodic polling

Output

Message Structure

javascript

{
  payload: [
    {
      name: "Product Inspection",
      id: "prod-inspect-v2",
      tags: {
        "OK": 1523,
        "DEFECT": 387,
        "ROTA": 149
      }
    },
    {
      name: "Quality Control",
      id: "qc-dataset-001",
      tags: {
        "PASS": 2000,
        "FAIL": 150
      }
    }
  ],
  reason: "startup",          // "startup", "update", "manual", "reset", "error"
  datasetsCount: 2,
  timestamp: "2024-01-15T10:30:00.000Z",
  options: [
    {
      label: "Product Inspection",
      value: "prod-inspect-v2"
    },
    {
      label: "Quality Control",
      value: "qc-dataset-001"
    }
  ]
}

Output Fields

payload (Array)

Array of dataset objects, each containing:

name: Human-readable dataset name
id: Unique dataset identifier
tags: Object mapping tag names to image counts

reason (String)

Why the message was sent:

"startup": Flow started or node deployed
"update": Dataset list changed in Firebase
"manual": Triggered by input message
"reset": Firebase reconnected
"error": Error occurred

datasetsCount (Number)

Total number of datasets in the list

timestamp (String)

ISO 8601 timestamp of when message was sent

options (Array)

Formatted for dropdown/select UI components:

label: Display name
value: Dataset ID for selection

Example Output

javascript

// Empty datasets
{
  payload: [],
  reason: "startup",
  datasetsCount: 0,
  timestamp: "2024-01-15T10:00:00.000Z",
  options: []
}

// Multiple datasets with tags
{
  payload: [
    {
      name: "Defect Detection",
      id: "defects-2024",
      tags: {
        "scratch": 450,
        "dent": 230,
        "crack": 120,
        "OK": 3200
      }
    }
  ],
  reason: "update",
  datasetsCount: 1,
  timestamp: "2024-01-15T10:05:00.000Z",
  options: [
    {
      label: "Defect Detection",
      value: "defects-2024"
    }
  ]
}

Node Status

Status Indicators

Fill	Shape	Text	Meaning
Yellow	Dot	`connecting (attempt N)`	Firebase connecting
Green	Dot	`connected`	Firebase connected
Green	Dot	`loaded: N dataset(s)`	Datasets loaded
Green	Dot	`updated: N dataset(s)`	Datasets updated
Yellow	Ring	`waiting for firebase`	Waiting for connection
Red	Ring	`connection error`	Firebase error
Red	Ring	`missing firebase-config`	Config not set
Red	Ring	`invalid output field`	Output path error

Usage Examples

[Inject: On Start] → [List Dataset] → [UI Dropdown]

UI Dropdown config:

javascript

// In dashboard dropdown node
msg.options = msg.options; // Use the options array
return msg;

Result: Dropdown populated with dataset names

Example 2: Dataset Statistics Dashboard

javascript

// Function node after List Dataset
const stats = msg.payload.map(ds => ({
  name: ds.name,
  totalImages: Object.values(ds.tags).reduce((sum, count) => sum + count, 0),
  tags: Object.keys(ds.tags).length
}));

msg.payload = stats;
return msg;

// Output:
// [
//   { name: "Dataset A", totalImages: 5000, tags: 5 },
//   { name: "Dataset B", totalImages: 3000, tags: 3 }
// ]

Example 3: Monitor New Datasets

javascript

// Function node: Track changes
const previous = context.get("previousCount") || 0;
const current = msg.datasetsCount;

if (current > previous) {
  msg.payload = `${current - previous} new dataset(s) added`;
  context.set("previousCount", current);
  return msg;  // Alert about new datasets
}

context.set("previousCount", current);
return null;  // No change

Example 4: Filter by Tag

javascript

// Function node: Find datasets with specific tag
const requiredTag = "DEFECT";

msg.payload = msg.payload.filter(dataset =>
  dataset.tags && requiredTag in dataset.tags
);

return msg;

Example 5: Create Dataset Summary

javascript

// Function node: Generate summary
const summary = {
  totalDatasets: msg.datasetsCount,
  timestamp: msg.timestamp,
  datasets: msg.payload.map(ds => {
    const totalImages = Object.values(ds.tags).reduce((sum, c) => sum + c, 0);
    const tagList = Object.keys(ds.tags).join(", ");

    return {
      name: ds.name,
      id: ds.id,
      totalImages: totalImages,
      tags: tagList,
      avgImagesPerTag: (totalImages / Object.keys(ds.tags).length).toFixed(0)
    };
  })
};

msg.payload = summary;
return msg;

Example 6: Conditional Workflow

[List Dataset] → [Switch: Check Count]
                   ├→ [Count > 0] → [Process Datasets]
                   └→ [Count = 0] → [Alert: No Datasets]

Switch node rules:

Rule 1: msg.datasetsCount > 0 → Output 1
Rule 2: msg.datasetsCount == 0 → Output 2

Integration Patterns

Pattern 1: Dynamic Dataset Selection

[List Dataset] → [UI Dropdown] → [User Selection] → [From Dataset]

Usage: User selects dataset, then loads images from it

Pattern 2: Periodic Monitoring

[Inject: Every 5min] → [List Dataset] → [Function: Check Changes] → [Alert]

Usage: Monitor for dataset additions/updates

Pattern 3: Multi-Output Dashboard

[List Dataset] ─┬→ [Chart: Dataset Counts]
                ├→ [Table: Dataset Details]
                └→ [Gauge: Total Images]

Usage: Multiple dashboard widgets from one source

Pattern 4: Conditional Processing

[List Dataset] → [Function: Filter] → [Dataset Upload]

Usage: Upload only to datasets matching criteria

Auto-Emit Behavior

On Startup

Node automatically emits dataset list when deployed
Reason: "startup"
Happens after Firebase connection established

On Firebase Updates

Emits when datasets change in Firebase
Reason: "update"
Real-time synchronization

On Firebase Reconnect

Emits after reconnection
Reason: "reset"
Ensures fresh data after connection loss

Error Handling

Missing Firebase Config

Error: "Missing firebase-config reference"

Cause: Firebase Config property not set

Solution: Configure Firebase Config dropdown in node settings

Connection Errors

Status: Red ring - "connection error"

Cause: Firebase authentication failed or network issue

Solution:

Check Firebase config credentials
Verify network connectivity
Check Firebase console for issues

Invalid Output Field

Error: "Failed to set output field"

Cause: Output field path is invalid

Solution: Use valid message property path (e.g., payload, datasets, data.list)

Performance Considerations

Memory Usage

Minimal: Only stores dataset metadata
No image data loaded
Scales well with hundreds of datasets

Network Usage

Initial load: Downloads dataset list from Firebase
Updates: Only changed datasets synced
Lightweight: Metadata only

Frequency

Startup: Once per deployment
Updates: Only when datasets change
Manual: On-demand via input

Best Practices

Use for UI selection: Ideal for dropdowns and selectors
Cache results: Store in context if needed repeatedly
Monitor changes: Use reason field to handle different triggers
Filter appropriately: Process only relevant datasets
Handle empty lists: Check datasetsCount before processing
Use options array: Pre-formatted for UI components

Troubleshooting

No datasets emitted

Possible causes:

Firebase not connected
No datasets in Firebase project
Firebase config incorrect

Solutions:

Check firebase-config node status
Verify Firebase console has datasets
Review Firebase credentials

Datasets not updating

Possible causes:

Real-time listener not active
Firebase connection dropped

Solutions:

Check node status for connection state
Send manual trigger to force update
Redeploy flow

Wrong output format

Possible causes:

Output field misconfigured
Expecting different structure

Solutions:

Verify output field path
Use function node to transform if needed
Check msg.payload structure

List Dataset Node ​

Overview ​

Key Features ​

Use Cases ​

Configuration ​

Properties ​

Output Field ​

Firebase Config ​

Input ​

Manual Trigger ​

Output ​

Message Structure ​

Output Fields ​

payload (Array) ​

reason (String) ​

datasetsCount (Number) ​

timestamp (String) ​

options (Array) ​

Example Output ​

Node Status ​

Status Indicators ​

Usage Examples ​

Example 1: Populate Dropdown ​

Example 2: Dataset Statistics Dashboard ​

Example 3: Monitor New Datasets ​

Example 4: Filter by Tag ​

Example 5: Create Dataset Summary ​

Example 6: Conditional Workflow ​

Integration Patterns ​

Pattern 1: Dynamic Dataset Selection ​

Pattern 2: Periodic Monitoring ​

Pattern 3: Multi-Output Dashboard ​

Pattern 4: Conditional Processing ​

Auto-Emit Behavior ​

On Startup ​

On Firebase Updates ​

On Firebase Reconnect ​

Error Handling ​

Missing Firebase Config ​

Connection Errors ​

Invalid Output Field ​

Performance Considerations ​

Memory Usage ​

Network Usage ​

Frequency ​

Best Practices ​

Troubleshooting ​

No datasets emitted ​

Datasets not updating ​

Wrong output format ​

See Also ​

List Dataset Node

Overview

Key Features

Use Cases

Configuration

Properties

Output Field

Firebase Config

Input

Manual Trigger

Output

Message Structure

Output Fields

payload (Array)

reason (String)

datasetsCount (Number)

timestamp (String)

options (Array)

Example Output

Node Status

Status Indicators

Usage Examples

Example 1: Populate Dropdown

Example 2: Dataset Statistics Dashboard

Example 3: Monitor New Datasets

Example 4: Filter by Tag

Example 5: Create Dataset Summary

Example 6: Conditional Workflow

Integration Patterns

Pattern 1: Dynamic Dataset Selection

Pattern 2: Periodic Monitoring

Pattern 3: Multi-Output Dashboard

Pattern 4: Conditional Processing

Auto-Emit Behavior

On Startup

On Firebase Updates

On Firebase Reconnect

Error Handling

Missing Firebase Config

Connection Errors

Invalid Output Field

Performance Considerations

Memory Usage

Network Usage

Frequency

Best Practices

Troubleshooting

No datasets emitted

Datasets not updating

Wrong output format

See Also