Power BI Relationship Visualizer¶

Interactive HTML visualization tool for Power BI semantic model relationships from TMDL files.

Live Demo¶

Try the interactive relationship visualizer with 6 sample Power BI models:

Switch between models using the dropdown (Model_A through Model_F)
Click any table to highlight its relationships (try both visualization modes)
Toggle modes between "All Relations" (direct connections) and "Filter Direction" (transitive filter chains)
Filter tables using the side panel to focus on specific areas of complex models
Interactive graph - zoom with mouse wheel, drag to pan, physics-based auto-layout

The demo shows real model relationships (with anonymized data) from models ranging from simple (2-3 relationships) to complex (14 relationships). Perfect for seeing the tool in action before running it on your own models.

Overview¶

This tool scans for Power BI semantic models in TMDL format, parses relationship definitions, and generates an interactive HTML diagram showing table relationships, cardinalities, and filter directions.

Key Features¶

🔍 Full Repository Visibility - Automatic Discovery: Recursively scans entire repo for all .SemanticModel folders, no manual configuration - Multi-Model Dropdown: Single HTML file contains all models found; switch between them instantly - Zero Setup: Just run the script and it finds everything

🎯 Interactive Model Filtering - Model Selector: Dropdown menu to switch between different semantic models in your workspace - Table Filter Panel: Click "📋 Filter Tables" button to show/hide specific tables from the visualization - Select All/Deselect All: Quickly toggle entire sets of tables on/off - Fact/Dimension Classification: Automatically identifies and color-codes table types based on relationship patterns - Visual Filtering: Focus on specific portions of complex models without losing context

🔗 Relationship Visualization Modes - All Relations Mode (default): Click any table to highlight all its direct relationships - Shows every table connected by at least one relationship - Great for understanding local connectivity - Filter Direction Mode: Click any table to visualize the complete filter propagation chain - Follows arrows transitively. If Table A filters B, and B filters C, all three are highlighted - Handles bidirectional relationships (many-to-many) by following both directions - Perfect for understanding how selections flow through your model - Toggle Button: Switch modes on the fly to analyze different aspects of model behavior

📊 Smart Visual Design - Fact Tables: Red rectangles (tables with more outgoing than incoming relationships) - Dimension Tables: Teal circles (tables with more incoming relationships) - One-Way Relationships: Dark gray arrows showing standard filter direction - Bidirectional Relationships: Purple arrows with wider lines (many-to-many) - Inactive Relationships: Dashed gray lines - Hover Tooltips: See cardinality, column mappings, and relationship status

🎨 Production-Ready Output - Self-Contained HTML: Single file (500KB-2MB) with all data and interactivity embedded - Offline Capable: No external dependencies except CDN-hosted vis.js library - Shareable: Send to stakeholders, embed in documentation, store in wikis - CI/CD Friendly: Generate relationship diagrams automatically in build pipelines - Interactive Physics: Zoom with mouse wheel, pan by dragging, auto-layout optimization

Prerequisites¶

Python: 3.7 or higher
Dependencies: None (uses Python standard library only)
Input Format: Power BI semantic models in TMDL format (.SemanticModel folders)

How to Run¶

Step 1: Download the script¶

Save visualize_all_relationships.py anywhere in your repo (root folder, scripts/, tools/, wherever works for you).

Or download via command line:

curl -O https://raw.githubusercontent.com/JoeRossouw/semantic_ops/main/scripts/visualize_all_relationships.py

Step 2: Open a terminal¶

In VS Code: Terminal → New Terminal (or press Ctrl+`)

Step 3: Run it¶

The command is python followed by the path to the script. How you write that path depends on where you saved the script.

Option A: Drag and drop (easiest)

Type python in your terminal (with a space after)
Drag the script file from Explorer into the terminal
Press Enter

The terminal pastes the full path for you.

Option B: Navigate to the script first

cd path/to/folder/containing/script
python visualize_all_relationships.py

Option C: Ask GitHub Copilot

In VS Code with Copilot, just ask:

"Run the visualize_all_relationships.py script"

Copilot will figure out the correct path and run it for you.

The script will:

Recursively search for all .SemanticModel folders
Parse all relationships.tmdl files found
Generate relationships_viewer.html in the current directory
Open the HTML file in your default browser

Advanced Options¶

# Skip opening browser
python visualize_all_relationships.py --no-browser

# Search a specific directory only
python visualize_all_relationships.py --search-path ./my_models

# Combine options
python visualize_all_relationships.py --search-path ./my_models --no-browser

Command-Line Options¶

| Option | Description | Default | |--------|-------------|---------|-----| | --search-path <path> | Limit search to specific directory | Scans entire repo recursively | | --no-browser | Skip automatically opening HTML in browser | Opens browser |

Expected Folder Structure¶

The script works with any folder structure containing Power BI semantic models in TMDL format:

your_project/
├── Sales.SemanticModel/
│   └── definition/
│       ├── relationships.tmdl    ← Parsed by this tool
│       ├── tables/
│       └── model.tmdl
├── Finance.SemanticModel/
│   └── definition/
│       └── relationships.tmdl    ← Parsed by this tool
└── my_models/
    └── Inventory.SemanticModel/
        └── definition/
            └── relationships.tmdl    ← Parsed by this tool

The script recursively searches for any *.SemanticModel/definition/relationships.tmdl files regardless of folder depth or naming conventions.

Interactive Viewer Features¶

Visualization Elements¶

Fact Tables: Red rectangles (tables with more outgoing than incoming relationships)
Dimension Tables: Teal circles (tables with more incoming than outgoing relationships)
One-Way Relationships: Dark gray arrows (standard filter direction)
Bidirectional Relationships: Purple arrows (both directions, wider line)
Inactive Relationships: Dashed gray lines

Interactive Controls¶

Model Selector: Dropdown menu to switch between different semantic models
Table Filter: Click "📋 Filter Tables" button to show/hide specific tables
Highlight Mode Toggle: Switch between:
All Relations: Shows all directly connected tables
Filter Direction: Shows transitive filter propagation chain
Click Interactions:
Click any table → Highlights related tables and relationships
Click empty space → Reset highlighting
Hover over elements → View tooltips with details
Navigation: Mouse wheel to zoom, click-drag to pan

Statistics Panel¶

Displays real-time counts for the selected model: - Total tables - Total relationships - Fact tables count - Dimension tables count

Output¶

The generated HTML file is self-contained (no external dependencies except CDN-hosted vis.js library) and includes:

All relationship data embedded as JSON
Full interactive visualization
CSS styling
JavaScript logic for interactivity

File size: Typically 500KB - 2MB depending on model complexity

Troubleshooting¶

No semantic models found¶

⚠️ No semantic models found with relationships.tmdl files
Expected structure: <ModelName>.SemanticModel/definition/relationships.tmdl

Solution: - Verify your models are in TMDL format (not .bim or legacy formats) - Check that relationships.tmdl files exist in the definition/ subfolder - Use --search-path to specify the correct directory

Empty visualization¶

If semantic models are found but no relationships appear, check that your relationships.tmdl files contain valid relationship definitions in TMDL format.

Browser doesn't open¶

Use the --no-browser flag and manually open the output HTML file, or check that you have a default browser configured.

CI/CD Integration¶

This tool works seamlessly in automated pipelines:

# Example GitHub Actions workflow
- name: Generate Relationship Diagrams
  run: |
    python visualize_all_relationships.py \
      --search-path ./semantic_models \
      --no-browser

- name: Upload Artifact
  uses: actions/upload-artifact@v3
  with:
    name: relationship-diagrams
    path: ./relationships_viewer.html

Technical Details¶

Parser: Custom regex-based TMDL relationship parser
Visualization Library: vis.js Network (loaded from CDN)
Graph Layout: ForceAtlas2 physics simulation
Browser Compatibility: Modern browsers (Chrome, Firefox, Edge, Safari)