node-red-contrib-json-filter-advanced

A powerful Node-RED node for interactive JSON filtering with a visual tree interface, template editor, and flexible output options.

Features

• Interactive Tree View: Visual representation of JSON structure with expandable/collapsible nodes
• Flexible Property Selection: Select any message property (msg.payload, msg.data, etc.) as the data source
• Template Editor: Build and test JSON structures directly in the editor
• Multiple Output Modes: Choose between Object, Flattened, or Array output formats
• Parent/Child Selection: Smart selection logic that automatically includes parent paths
• Real-time Preview: See your JSON structure as you work with live messages
• Professional UI: Clean, Node-RED-styled interface with intuitive controls

Installation

npm install node-red-contrib-json-filter-advanced

Or install via the Node-RED palette manager.

Usage

Basic Setup

1. Drag the "json filter advanced" node into your flow
2. Double-click to open the configuration dialog
3. Select your data source:
   • Use Latest Message: Work with live data from your flow
   • Use JSON Template: Define a JSON structure for testing

Configuration Options

Property Selection

• Property: Choose which message property to filter (default: payload)
• Supports nested properties like data.items, response.body, etc.

Output Modes

• Object: Returns the filtered data as a nested object structure
• Flattened: Returns key-value pairs with dot-notation keys
• Array: Returns an array of the selected leaf values

Data Sources

• Use Latest Message: Automatically loads the structure from the last message received
• Use JSON Template: Define your own JSON structure for testing and development

Tree Navigation

• Expand/Collapse: Click the arrow icons or use the "Expand All"/"Collapse All" buttons
• Selection: Check boxes to select specific fields
• Parent/Child Logic: Selecting a parent automatically includes its children
• Visual Feedback: Selected items are highlighted with different colors

Examples

Example 1: Basic Filtering

Input Message:

{
  "user": {
    "name": "John Doe",
    "email": "[email protected]",
    "address": {
      "street": "123 Main St",
      "city": "New York",
      "zip": "10001"
    }
  },
  "timestamp": "2024-01-01T00:00:00Z"
}

Selected Paths: user.name, user.email, user.address.city

Output (Object mode):

{
  "user": {
    "name": "John Doe",
    "email": "[email protected]",
    "address": {
      "city": "New York"
    }
  }
}

Output (Flattened mode):

{
  "user.name": "John Doe",
  "user.email": "[email protected]",
  "user.address.city": "New York"
}

Output (Array mode):

["John Doe", "[email protected]", "New York"]

Example 2: Working with Arrays

Input Message:

{
  "products": [
    {
      "id": 1,
      "name": "Laptop",
      "price": 999.99,
      "category": "Electronics"
    },
    {
      "id": 2,
      "name": "Mouse",
      "price": 29.99,
      "category": "Electronics"
    }
  ]
}

Selected Paths: products.name, products.price

Output (Object mode):

{
  "products": [
    {
      "name": "Laptop",
      "price": 999.99
    },
    {
      "name": "Mouse",
      "price": 29.99
    }
  ]
}

Use Cases

API Response Filtering

Filter large API responses to extract only the data you need, reducing payload size and improving performance.

Data Transformation

Convert between different JSON structures while preserving the relationships between fields.

Development and Testing

Use the template editor to prototype JSON structures before connecting to live data sources.

Message Routing

Extract specific fields for routing decisions or conditional processing.

Technical Details

Node Properties

• name: Optional display name for the node
• property: Message property to filter (supports dot notation)
• mode: Output format (object/flattened/array)
• selectedPaths: Array of selected JSON paths
• sourceType: Data source type (message/template)
• templateData: JSON template for testing

Performance Considerations

• Maximum JSON size: 1MB
• Maximum tree nodes: 1000
• Debounced updates for better performance
• Efficient tree rendering with virtual scrolling

Security Features

• Input validation and sanitization
• XSS prevention in UI components
• Safe JSON parsing with error handling
• Size limits to prevent memory issues

Error Handling

The node includes comprehensive error handling:

• Invalid JSON structure detection
• Property path validation
• Size limit enforcement
• User-friendly error messages
• Graceful fallback behavior

Requirements

• Node-RED 2.0.0 or higher
• Node.js 14.0.0 or higher

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

License

MIT License - see LICENSE file for details.

Changelog

1.0.26

• Improved output mode terminology (Object/Flattened/Array)
• Enhanced property selection with typedInput component
• Better error handling and validation
• Performance optimizations

1.0.25

• Added property selection support
• Modular code architecture
• Enhanced security features
• UI improvements

1.0.0

• Initial release
• Interactive tree view
• Template editor
• Multiple output modes
• Parent/child selection logic