tools-only Install Learning Graph Viewer
Overview
This skill installs a complete interactive graph visualization application into the /docs/sims/graph-viewer/ directory of an intelligent textbook project. The viewer provides an interactive way to explore learning graphs with features like node search, category filtering, and real-time statistics.
When to Use This Skill
Use this skill when:
- A learning graph has been generated (learning-graph.json exists in /docs/learning-graph/)
- The textbook needs an interactive visualization tool for exploring concept dependencies
- Students or instructors need to filter, search, and analyze the learning graph structure
Prerequisites:
/docs/learning-graph/learning-graph.jsonmust exist- The JSON file must have metadata with a
titlefield - The JSON file must have proper
classifierNamevalues in groups (see Step 3.5) - MkDocs project structure must be in place
Installation Workflow
Step 1: Verify Prerequisites
Before installation, verify that the learning graph JSON file exists:
ls docs/learning-graph/learning-graph.json
If the file doesn't exist, use the learning-graph-generator skill first to create the learning graph.
Step 1b: Validate classifierName Values (CRITICAL)
This step prevents the common bug where taxonomy IDs appear instead of human-readable names in the legend.
Run this validation to check that all classifierName values are human-readable:
python3 -c "
import json
with open('docs/learning-graph/learning-graph.json') as f:
data = json.load(f)
issues = []
for gid, ginfo in data['groups'].items():
name = ginfo.get('classifierName', '')
if name == gid:
issues.append(f\"❌ {gid}: classifierName equals ID - needs human-readable name\")
else:
print(f'✅ {gid}: {name}')
if issues:
print()
for issue in issues:
print(issue)
print()
print('⚠️ FIX REQUIRED: Update learning-graph.json groups with proper classifierName values')
print(' Or regenerate with: python csv-to-json.py ... taxonomy-names.json')
"
If any classifierName equals its taxonomy ID:
- Check if
docs/learning-graph/taxonomy-names.jsonexists with proper mappings - If it exists, regenerate learning-graph.json using:
cd docs/learning-graph python csv-to-json.py learning-graph.csv learning-graph.json color-config.json metadata.json taxonomy-names.json - If it doesn't exist, manually update learning-graph.json with human-readable names
Common fixes:
| Taxonomy ID | Should be classifierName |
|---|---|
| FOUND | Foundation Concepts |
| EDA1 | Exploratory Data Analysis I |
| REG | Regression & Correlation |
| PROB | Probability |
| SAMP | Sampling Distributions |
Do not proceed until all classifierName values are human-readable.
Step 2: Create Directory Structure
Create the graph-viewer directory:
mkdir -p docs/sims/graph-viewer
Step 3: Create main.html
Create docs/sims/graph-viewer/main.html with the following structure:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Learning Graph Viewer for TITLE</title>
<script src="https://unpkg.com/vis-network/standalone/umd/vis-network.min.js"></script>
<link rel="stylesheet" href="local.css">
</head>
<body>
<div class="container">
<div class="sidebar" id="sidebar">
<div class="sidebar-header">
<h4>Learning Graph for TITLE</h4>
<button id="toggle-sidebar" class="toggle-btn" title="Toggle Sidebar">☰</button>
</div>
<div class="sidebar-content" id="sidebar-content">
<div class="search-container">
<label for="search">Search Concepts:</label>
<input type="text" id="search" placeholder="Type to search...">
<div id="search-results" class="search-results"></div>
</div>
<div class="legend-container">
<h5>Categories</h5>
<div class="legend-controls">
<button id="check-all" class="legend-btn">Check All</button>
<button id="uncheck-all" class="legend-btn">Uncheck All</button>
</div>
<div id="legend"></div>
</div>
<div class="stats-container">
<h5>Statistics</h5>
<div id="stats">
<p>Visible Nodes: <span id="visible-nodes">0</span></p>
<p>Visible Edges: <span id="visible-edges">0</span></p>
<p>Foundational: <span id="foundational-nodes">0</span></p>
</div>
</div>
</div>
</div>
<div class="graph-container" id="graph-container">
<div id="network"></div>
</div>
</div>
<script src="script.js"></script>
</body>
</html>
Replace "TITLE" with the course title from learning-graph.json metadata.
Step 4: Create local.css
Create docs/sims/graph-viewer/local.css with all sidebar and layout styling:
/* Learning Graph Viewer Styles */
/* ================================
RESET AND BASE STYLES
================================ */
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
background-color: #f5f5f5;
overflow: hidden;
}
/* ================================
MAIN LAYOUT CONTAINER
Uses flexbox for sidebar + graph layout
================================ */
.container {
display: flex;
height: 100vh;
width: 100vw;
}
/* ================================
SIDEBAR STYLES
Collapsible sidebar with search, legend, and stats
================================ */
.sidebar {
/* Width settings - adjust for label wrapping */
width: 200px;
min-width: 200px;
/* Visual styling */
background-color: #fff;
border-right: 1px solid #ddd;
/* Flexbox for internal layout */
display: flex;
flex-direction: column;
/* Smooth collapse animation */
transition: width 0.3s ease, min-width 0.3s ease;
overflow: hidden;
}
/* Collapsed state - narrow width shows only toggle button */
.sidebar.collapsed {
width: 50px;
min-width: 50px;
}
/* ================================
SIDEBAR HEADER
Contains title and toggle button
================================ */
.sidebar-header {
display: flex;
justify-content: space-between;
align-items: center;
padding: 15px;
background-color: #2196F3; /* Blue header bar */
color: white;
}
.sidebar-header h4 {
font-size: 14px;
font-weight: 600;
margin: 0;
white-space: nowrap;
overflow: hidden;
text-overflow: ellipsis; /* Truncate long titles */
}
/* Hide title when collapsed */
.sidebar.collapsed .sidebar-header h4 {
display: none;
}
/* ================================
TOGGLE BUTTON
Hamburger menu icon for collapse/expand
================================ */
.toggle-btn {
background: none;
border: none;
color: white;
font-size: 20px;
cursor: pointer;
padding: 5px;
border-radius: 4px;
}
.toggle-btn:hover {
background-color: rgba(255,255,255,0.2);
}
/* ================================
SIDEBAR CONTENT
Scrollable area containing search, legend, stats
================================ */
.sidebar-content {
flex: 1;
overflow-y: auto;
padding: 15px;
}
/* ================================
SEARCH CONTAINER STYLES
Type-ahead search for finding concepts
================================ */
.search-container {
margin-bottom: 20px;
}
.search-container label {
display: block;
font-weight: 600;
margin-bottom: 8px;
color: #333;
}
.search-container input {
width: 100%;
padding: 10px 12px;
border: 1px solid #ddd;
border-radius: 6px;
font-size: 14px;
transition: border-color 0.2s;
}
.search-container input:focus {
outline: none;
border-color: #2196F3;
box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1); /* Blue focus ring */
}
/* ================================
SEARCH RESULTS DROPDOWN
Positioned absolutely below search input
================================ */
.search-results {
display: none; /* Hidden by default */
position: absolute;
width: calc(100% - 30px); /* Account for sidebar padding */
background: white;
border: 1px solid #ddd;
border-radius: 6px;
box-shadow: 0 4px 12px rgba(0,0,0,0.15);
max-height: 300px;
overflow-y: auto;
z-index: 100; /* Above other content */
margin-top: 4px;
}
.search-result-item {
padding: 10px 12px;
cursor: pointer;
display: flex;
justify-content: space-between;
align-items: center;
border-bottom: 1px solid #eee;
}
.search-result-item:last-child {
border-bottom: none;
}
.search-result-item:hover {
background-color: #f5f5f5;
}
.result-label {
font-weight: 500;
color: #333;
}
/* Category badge in search results */
.result-category {
font-size: 11px;
padding: 3px 8px;
border-radius: 12px;
color: #333;
}
/* ================================
LEGEND CONTAINER STYLES
Category filtering with checkboxes
================================ */
.legend-container {
margin-bottom: 20px;
}
.legend-container h5 {
font-weight: 600;
margin-bottom: 10px;
color: #333;
}
/* Check All / Uncheck All buttons */
.legend-controls {
display: flex;
gap: 8px;
margin-bottom: 12px;
}
.legend-btn {
flex: 1;
padding: 6px 10px;
font-size: 12px;
border: 1px solid #ddd;
background: #fff;
border-radius: 4px;
cursor: pointer;
transition: all 0.2s;
}
.legend-btn:hover {
background: #f0f0f0;
border-color: #bbb;
}
/* Legend items container - scrollable for many categories */
#legend {
max-height: 400px;
overflow-y: auto;
}
/* Individual legend item (checkbox + color + label) */
.legend-item {
display: flex;
align-items: center;
padding: 6px 0;
gap: 8px;
}
.legend-item input[type="checkbox"] {
width: 16px;
height: 16px;
cursor: pointer;
}
/* Color swatch box */
.color-box {
width: 20px;
height: 20px;
border-radius: 4px;
border: 1px solid rgba(0,0,0,0.1);
flex-shrink: 0; /* Don't shrink color box */
}
.legend-item label {
font-size: 13px;
color: #555;
cursor: pointer;
flex: 1;
}
/* ================================
STATISTICS CONTAINER STYLES
Shows counts of visible nodes, edges, foundational
================================ */
.stats-container {
background-color: #f9f9f9;
padding: 12px;
border-radius: 6px;
}
.stats-container h5 {
font-weight: 600;
margin-bottom: 10px;
color: #333;
}
#stats p {
font-size: 13px;
color: #666;
margin-bottom: 6px;
}
#stats span {
font-weight: 600;
color: #2196F3; /* Blue accent for numbers */
}
/* ================================
GRAPH CONTAINER STYLES
Main visualization area
================================ */
.graph-container {
flex: 1; /* Take remaining space */
position: relative;
background-color: aliceblue; /* Light blue background */
}
#network {
width: 100%;
height: 100%;
}
/* ================================
RESPONSIVE ADJUSTMENTS
Mobile-friendly sidebar widths
================================ */
@media (max-width: 768px) {
.sidebar {
width: 250px;
min-width: 250px;
}
.sidebar.collapsed {
width: 40px;
min-width: 40px;
}
}
Step 5: Create script.js
Create docs/sims/graph-viewer/script.js with the visualization logic:
// Learning Graph Viewer Script
// Loads and displays an interactive learning graph using vis-network
let network = null;
let allNodes = [];
let allEdges = [];
let groups = {};
let visibleGroups = new Set();
// Load the learning graph data
async function loadGraph() {
try {
const response = await fetch('../../learning-graph/learning-graph.json');
const data = await response.json();
allNodes = data.nodes || [];
allEdges = data.edges || [];
groups = data.groups || {};
// Initialize all groups as visible
Object.keys(groups).forEach(g => visibleGroups.add(g));
initializeNetwork();
buildLegend();
updateStats();
setupSearch();
setupControls();
} catch (error) {
console.error('Error loading learning graph:', error);
document.getElementById('network').innerHTML =
'<p style="color: red; padding: 20px;">Error loading learning graph. Make sure learning-graph.json exists.</p>';
}
}
// Initialize the vis-network visualization
function initializeNetwork() {
const container = document.getElementById('network');
// Create nodes DataSet - colors are handled by the groups option
const nodes = new vis.DataSet(allNodes);
// Create edges DataSet
const edges = new vis.DataSet(allEdges.map(edge => ({
...edge,
arrows: 'to',
color: { color: '#888', opacity: 0.6 }
})));
const data = { nodes, edges };
// Build vis-network groups configuration from JSON groups
const visGroups = {};
Object.entries(groups).forEach(([groupId, groupInfo]) => {
visGroups[groupId] = {
color: {
background: groupInfo.color || 'lightgray',
border: groupInfo.color || 'lightgray',
highlight: {
background: groupInfo.color || 'lightgray',
border: '#333'
},
hover: {
background: groupInfo.color || 'lightgray',
border: '#666'
}
},
font: {
color: groupInfo.font?.color || 'black'
}
};
});
const options = {
groups: visGroups,
layout: {
randomSeed: 42,
improvedLayout: true
},
physics: {
enabled: true,
solver: 'forceAtlas2Based',
forceAtlas2Based: {
gravitationalConstant: -50,
centralGravity: 0.01,
springLength: 100,
springConstant: 0.08,
damping: 0.4,
avoidOverlap: 0.5
},
stabilization: {
enabled: true,
iterations: 1000,
updateInterval: 25
}
},
nodes: {
shape: 'box',
margin: 4,
font: {
size: 14,
face: 'Arial'
},
borderWidth: 2,
shadow: true
},
edges: {
smooth: {
type: 'cubicBezier',
forceDirection: 'horizontal',
roundness: 0.4
},
width: 1.5
},
interaction: {
hover: true,
tooltipDelay: 200,
zoomView: true,
dragView: true
}
};
network = new vis.Network(container, data, options);
// Turn off physics after 5 seconds to stop spinning
setTimeout(() => {
network.setOptions({ physics: { enabled: false } });
}, 5000);
// Re-enable physics when user starts dragging a node
network.on('dragStart', function(params) {
if (params.nodes.length > 0) {
network.setOptions({ physics: { enabled: true } });
}
});
// Turn off physics when user releases the node
network.on('dragEnd', function(params) {
if (params.nodes.length > 0) {
// Brief delay to let physics settle the dragged node
setTimeout(() => {
network.setOptions({ physics: { enabled: false } });
}, 1000);
}
});
// Handle node selection
network.on('selectNode', function(params) {
if (params.nodes.length > 0) {
const nodeId = params.nodes[0];
const node = allNodes.find(n => n.id === nodeId);
if (node) {
highlightNode(nodeId);
}
}
});
}
// Build the category legend
function buildLegend() {
const legendContainer = document.getElementById('legend');
legendContainer.innerHTML = '';
Object.entries(groups).forEach(([groupId, groupInfo]) => {
const count = allNodes.filter(n => n.group === groupId).length;
const item = document.createElement('div');
item.className = 'legend-item';
const checkbox = document.createElement('input');
checkbox.type = 'checkbox';
checkbox.id = `group-${groupId}`;
checkbox.checked = true;
checkbox.addEventListener('change', () => toggleGroup(groupId, checkbox.checked));
const colorBox = document.createElement('span');
colorBox.className = 'color-box';
colorBox.style.backgroundColor = groupInfo.color || 'lightgray';
const label = document.createElement('label');
label.htmlFor = `group-${groupId}`;
label.textContent = `${groupInfo.classifierName || groupId} (${count})`;
item.appendChild(checkbox);
item.appendChild(colorBox);
item.appendChild(label);
legendContainer.appendChild(item);
});
}
// Toggle visibility of a category group
function toggleGroup(groupId, visible) {
if (visible) {
visibleGroups.add(groupId);
} else {
visibleGroups.delete(groupId);
}
updateVisibility();
}
// Update node and edge visibility based on selected groups
function updateVisibility() {
const visibleNodeIds = new Set(
allNodes.filter(n => visibleGroups.has(n.group)).map(n => n.id)
);
const nodes = network.body.data.nodes;
const edges = network.body.data.edges;
// Update node visibility
allNodes.forEach(node => {
const isVisible = visibleGroups.has(node.group);
nodes.update({
id: node.id,
hidden: !isVisible
});
});
// Update edge visibility (hide if either endpoint is hidden)
allEdges.forEach(edge => {
const isVisible = visibleNodeIds.has(edge.from) && visibleNodeIds.has(edge.to);
edges.update({
id: edge.id || `${edge.from}-${edge.to}`,
hidden: !isVisible
});
});
updateStats();
}
// Update statistics display
function updateStats() {
const visibleNodeIds = new Set(
allNodes.filter(n => visibleGroups.has(n.group)).map(n => n.id)
);
const visibleEdgeCount = allEdges.filter(
e => visibleNodeIds.has(e.from) && visibleNodeIds.has(e.to)
).length;
// Count foundational nodes (nodes with no outgoing dependencies)
const nodesWithDeps = new Set(allEdges.map(e => e.from));
const foundationalCount = allNodes.filter(
n => !nodesWithDeps.has(n.id) && visibleGroups.has(n.group)
).length;
document.getElementById('visible-nodes').textContent = visibleNodeIds.size;
document.getElementById('visible-edges').textContent = visibleEdgeCount;
document.getElementById('foundational-nodes').textContent = foundationalCount;
}
// Setup search functionality
function setupSearch() {
const searchInput = document.getElementById('search');
const resultsContainer = document.getElementById('search-results');
searchInput.addEventListener('input', function() {
const query = this.value.toLowerCase().trim();
resultsContainer.innerHTML = '';
if (query.length < 2) {
resultsContainer.style.display = 'none';
return;
}
const matches = allNodes.filter(n =>
n.label.toLowerCase().includes(query)
).slice(0, 10);
if (matches.length === 0) {
resultsContainer.style.display = 'none';
return;
}
matches.forEach(node => {
const item = document.createElement('div');
item.className = 'search-result-item';
const groupInfo = groups[node.group] || {};
item.innerHTML = `
<span class="result-label">${node.label}</span>
<span class="result-category" style="background-color: ${groupInfo.color || 'lightgray'}">
${groupInfo.classifierName || node.group}
</span>
`;
item.addEventListener('click', () => {
selectNode(node.id);
searchInput.value = node.label;
resultsContainer.style.display = 'none';
});
resultsContainer.appendChild(item);
});
resultsContainer.style.display = 'block';
});
// Hide results when clicking outside
document.addEventListener('click', function(e) {
if (!searchInput.contains(e.target) && !resultsContainer.contains(e.target)) {
resultsContainer.style.display = 'none';
}
});
}
// Select and focus on a node
function selectNode(nodeId) {
network.selectNodes([nodeId]);
network.focus(nodeId, {
scale: 1.2,
animation: {
duration: 500,
easingFunction: 'easeInOutQuad'
}
});
highlightNode(nodeId);
}
// Highlight a node and its connections
function highlightNode(nodeId) {
const connectedNodes = network.getConnectedNodes(nodeId);
const allConnected = [nodeId, ...connectedNodes];
// Reset all nodes to normal opacity
const nodes = network.body.data.nodes;
allNodes.forEach(node => {
const isConnected = allConnected.includes(node.id);
nodes.update({
id: node.id,
opacity: isConnected ? 1 : 0.3
});
});
// Reset opacity after a delay
setTimeout(() => {
allNodes.forEach(node => {
nodes.update({
id: node.id,
opacity: 1
});
});
}, 3000);
}
// Setup control buttons
function setupControls() {
// Toggle sidebar
document.getElementById('toggle-sidebar').addEventListener('click', function() {
const sidebar = document.getElementById('sidebar');
const content = document.getElementById('sidebar-content');
sidebar.classList.toggle('collapsed');
content.style.display = sidebar.classList.contains('collapsed') ? 'none' : 'block';
});
// Check all groups
document.getElementById('check-all').addEventListener('click', function() {
Object.keys(groups).forEach(groupId => {
visibleGroups.add(groupId);
document.getElementById(`group-${groupId}`).checked = true;
});
updateVisibility();
});
// Uncheck all groups
document.getElementById('uncheck-all').addEventListener('click', function() {
Object.keys(groups).forEach(groupId => {
visibleGroups.delete(groupId);
document.getElementById(`group-${groupId}`).checked = false;
});
updateVisibility();
});
}
// Initialize when DOM is ready
document.addEventListener('DOMContentLoaded', loadGraph);
Step 6: Create index.md
Create docs/sims/graph-viewer/index.md with documentation:
# Learning Graph Viewer
This interactive viewer allows you to explore the learning graph for the course.
## Features
- **Search**: Type in the search box to find specific concepts
- **Category Filtering**: Use checkboxes to show/hide concept categories
- **Interactive Navigation**: Click and drag to explore, scroll to zoom
- **Statistics**: View real-time counts of visible nodes and edges
## Using the Viewer
1. **Search for Concepts**: Start typing in the search box to find concepts. Click on a result to focus on that node.
2. **Filter by Category**: Use the category checkboxes in the sidebar to show or hide groups of related concepts. Use "Check All" or "Uncheck All" for bulk operations.
3. **Navigate the Graph**:
- Drag to pan around the graph
- Scroll to zoom in and out
- Click on a node to select it and highlight its connections
4. **View Statistics**: The sidebar shows counts of visible nodes, edges, and foundational concepts.
## Graph Structure
- **Foundational Concepts** (left side): Prerequisites with no dependencies
- **Advanced Concepts** (right side): Topics that build on multiple prerequisites
- **Edges**: Arrows point from a concept to its prerequisites
## Launch the Viewer
[Open Learning Graph Viewer](./main.html){ .md-button .md-button--primary }
<iframe src="./main.html" width="100%" height="600px" frameborder="0"></iframe>
Step 7: Verify classifierName Values in JSON (IMPORTANT)
The learning-graph.json file must have human-readable classifierName values in the groups section. This is critical for the legend to display correctly.
Check the groups section of learning-graph.json:
"groups": {
"FOUND": {
"classifierName": "Foundation Concepts", // CORRECT - human readable
"color": "LightCoral"
},
"BLOOM": {
"classifierName": "BLOOM", // WRONG - just the ID, not human readable
"color": "PeachPuff"
}
}
If any classifierName values are just the group ID (like "BLOOM", "VISUA"), update them to be human-readable (like "Bloom's Taxonomy", "Visualization Types").
Common taxonomy mappings:
| Group ID | classifierName |
|---|---|
| FOUND | Foundation Concepts |
| BLOOM | Bloom's Taxonomy |
| VISUA | Visualization Types |
| LIBRA | Libraries & Tools |
| SPECI | Specification |
| COGNI | Cognitive Science |
| AUDIE | Audience Adaptation |
| EVALU | Evaluation & Testing |
| ITERA | Iteration & Workflow |
| ACCES | Accessibility |
| DEPLO | Deployment |
| CAPST | Capstone |
Step 8: Update Title in main.html
Replace the "TITLE" placeholder in main.html with the course title:
- Extract title from learning-graph.json metadata
- In
docs/sims/graph-viewer/main.html, replace all instances of "TITLE" with the actual course title - This appears in two locations:
- The
<title>tag:<title>Learning Graph Viewer for TITLE</title> - The page heading:
<h4>Learning Graph for TITLE</h4>
- The
Step 9: Update MkDocs Navigation (Optional)
If the user wants the graph viewer in the site navigation, add it to mkdocs.yml:
nav:
- MicroSims:
- Graph Viewer: sims/graph-viewer/index.md
Step 10: Inform the User
Provide the user with instructions to test the installation:
- Run
mkdocs serveto start the local development server - Navigate to the appropriate URL based on their repository name:
- Format:
http://localhost:8000/REPO_NAME/sims/graph-viewer/main.html
- Format:
- Alternatively, access it through the MkDocs site menu if added to navigation
vis-network Options Reference
The viewer uses these vis-network configuration options:
Groups Configuration
Purpose: Maps learning graph taxonomy groups to vis-network colors so legend and nodes match.
const visGroups = {};
Object.entries(groups).forEach(([groupId, groupInfo]) => {
visGroups[groupId] = {
color: {
background: groupInfo.color || 'lightgray', // Node fill color
border: groupInfo.color || 'lightgray', // Node border color
highlight: {
background: groupInfo.color || 'lightgray',
border: '#333' // Dark border when selected
},
hover: {
background: groupInfo.color || 'lightgray',
border: '#666' // Medium border on hover
}
},
font: {
color: groupInfo.font?.color || 'black' // Label text color
}
};
});
Layout Options
Purpose: Controls initial node positioning. Uses physics-based layout (NOT hierarchical).
layout: {
randomSeed: 42, // Consistent initial positions across reloads
improvedLayout: true // Better initial spread before physics kicks in
}
Important: Do NOT use hierarchical layout for learning graphs - it doesn't work well with complex DAGs.
Physics Options
Purpose: Controls force-directed graph simulation for node positioning.
physics: {
enabled: true,
solver: 'forceAtlas2Based', // Best solver for large graphs
forceAtlas2Based: {
gravitationalConstant: -50, // Repulsion force (negative = push apart)
centralGravity: 0.01, // Pull toward center (low = spread out)
springLength: 100, // Ideal edge length in pixels
springConstant: 0.08, // Edge spring stiffness
damping: 0.4, // Velocity damping (higher = slower settling)
avoidOverlap: 0.5 // Node overlap prevention (0-1)
},
stabilization: {
enabled: true,
iterations: 1000, // Stabilization iterations before render
updateInterval: 25 // Progress update frequency (ms)
}
}
Node Options
Purpose: Visual appearance of concept nodes.
nodes: {
shape: 'box', // Rectangular nodes (good for text labels)
margin: 4, // Padding inside node box
font: {
size: 14, // Label font size
face: 'Arial' // Font family
},
borderWidth: 2, // Node border thickness
shadow: true // Drop shadow for depth
}
Edge Options
Purpose: Visual appearance of dependency arrows.
edges: {
smooth: {
type: 'cubicBezier', // Curved edges
forceDirection: 'horizontal', // Curves bend horizontally
roundness: 0.4 // Curve intensity (0-1)
},
width: 1.5 // Line thickness
}
Note on edge creation: Edges are created with arrows and muted color:
edges = new vis.DataSet(allEdges.map(edge => ({
...edge,
arrows: 'to', // Arrowhead at target
color: { color: '#888', opacity: 0.6 } // Gray, semi-transparent
})));
Interaction Options
Purpose: User interaction controls.
interaction: {
hover: true, // Enable hover effects
tooltipDelay: 200, // Delay before tooltip appears (ms)
zoomView: true, // Allow scroll-to-zoom
dragView: true // Allow click-and-drag panning
}
CSS Reference
Layout Classes
| Class | Purpose |
|---|---|
.container |
Flex container holding sidebar + graph (100vw × 100vh) |
.sidebar |
Left sidebar (200px width, collapsible to 50px) |
.sidebar.collapsed |
Collapsed state styling |
.sidebar-content |
Scrollable content area inside sidebar |
.graph-container |
Main graph area (flex: 1, fills remaining space) |
#network |
vis-network canvas (100% × 100%) |
Sidebar Header Classes
| Class | Purpose |
|---|---|
.sidebar-header |
Blue header bar with title and toggle |
.sidebar-header h4 |
Title text (truncates with ellipsis) |
.toggle-btn |
Hamburger menu button (☰) |
Search Classes
| Class | Purpose |
|---|---|
.search-container |
Wrapper for search input and results |
.search-results |
Dropdown with matching concepts |
.search-result-item |
Individual search result row |
.result-label |
Concept name in search result |
.result-category |
Category badge in search result |
Legend Classes
| Class | Purpose |
|---|---|
.legend-container |
Wrapper for category legend |
.legend-controls |
Check All / Uncheck All buttons |
.legend-btn |
Individual control button |
#legend |
Container for legend items (scrollable) |
.legend-item |
Single category row (checkbox + color + label) |
.color-box |
20×20px color swatch |
Statistics Classes
| Class | Purpose |
|---|---|
.stats-container |
Gray background box for stats |
#stats |
Container for stat paragraphs |
#visible-nodes |
Span for node count (blue text) |
#visible-edges |
Span for edge count (blue text) |
#foundational-nodes |
Span for foundational count (blue text) |
Key CSS Variables/Colors
| Element | Color | Usage |
|---|---|---|
| Sidebar header | #2196F3 |
Blue Material Design primary |
| Focus ring | rgba(33, 150, 243, 0.1) |
Light blue focus glow |
| Stats numbers | #2196F3 |
Blue accent for statistics |
| Graph background | aliceblue |
Light blue canvas background |
| Borders | #ddd |
Light gray for borders |
| Text primary | #333 |
Dark gray for headings |
| Text secondary | #555 / #666 |
Medium gray for labels |
Common Issues and Fixes
Issue 1: Legend colors don't match node colors
Symptom: When filtering by category, the visible nodes are a different color than the legend swatch.
Cause: The script must pass the groups configuration to vis-network's groups option.
Fix: Ensure script.js builds visGroups from JSON and passes to options:
const options = {
groups: visGroups, // This is required!
// ... other options
};
Issue 2: Legend shows group IDs instead of readable names
Symptom: The legend shows "FOUND", "BLOOM" instead of "Foundation Concepts", "Bloom's Taxonomy".
Cause: The classifierName values in learning-graph.json are set to the group IDs.
Fix: Update the groups section in learning-graph.json to have proper classifierName values.
Issue 3: Hierarchical layout doesn't work well
Symptom: The graph layout is messy or nodes overlap badly.
Cause: Hierarchical layout doesn't work well with DAGs that have complex dependency structures.
Fix: Use physics-based layout with forceAtlas2Based solver (as shown in script.js).
Issue 4: Graph keeps spinning indefinitely
Symptom: The graph keeps moving for a long time before settling.
Cause: Physics simulation continues running without a timeout.
Fix: The script automatically disables physics after 5 seconds:
// Turn off physics after 5 seconds to stop spinning
setTimeout(() => {
network.setOptions({ physics: { enabled: false } });
}, 5000);
Physics is re-enabled when dragging nodes to allow repositioning, then disabled again after 1 second.
Viewer Features
The installed graph viewer provides:
Search Functionality:
- Type-ahead search with dropdown results
- Shows category information for each node
- Focuses and selects matching nodes in the visualization
Category Filtering:
- Sidebar legend with color-coded categories
- Checkboxes to show/hide specific taxonomy groups
- "Check All" and "Uncheck All" bulk operations
- Collapsible sidebar for expanded viewing
Real-time Statistics:
- Visible node count
- Visible edge count
- Foundational node count (concepts with no dependencies)
Interactive Visualization:
- vis-network graph with physics simulation (auto-stops after 5 seconds)
- Color-coded nodes by taxonomy category
- Directed edges showing concept dependencies
- Zoomable and draggable interface
- Node highlight on selection (dims unconnected nodes)
- Drag nodes to reposition (physics re-enables temporarily)
Technical Details
File Structure:
docs/sims/graph-viewer/
├── main.html # Main application HTML
├── script.js # JavaScript logic for visualization
├── local.css # Styling for the viewer
└── index.md # Documentation page with iframe embed
Dependencies:
- vis-network.js (loaded from CDN:
https://unpkg.com/vis-network/standalone/umd/vis-network.min.js) - learning-graph.json (loaded from
../../learning-graph/learning-graph.json)
Data Path:
The script.js file loads the learning graph from a relative path: ../../learning-graph/learning-graph.json. This assumes the standard intelligent textbook structure where /docs/sims/ and /docs/learning-graph/ are siblings.