@pmsite/chronograph

A reactive state management and scheduling engine for Gantt charts, powered by Rust and WebAssembly.

Features

• Reactive Computation Engine: Variables, computed identifiers, automatic dependency tracking
• Undo/Redo: Built-in transaction history with configurable depth
• CPM Scheduling: Critical Path Method with forward/backward pass
• Calendar Support: Working days, hours, holidays, and exceptions
• Resource Shifts: Define shift patterns (morning, evening, custom) for resources
• Resource Leveling: Automatic conflict resolution with multiple strategies
• Custom Fields: User-defined fields with type validation for tasks, resources, and projects
• Project Save/Load: Export and import complete project state as JSON
• High Performance: Rust-compiled WASM for near-native speed

Installation

npm install @pmsite/chronograph

Quick Start

Reactive State Management

import init, { ChronoGraph, ChronoGraphConfig } from '@pmsite/chronograph';

await init();

const config = new ChronoGraphConfig();
config.historyLimit = 50;
const graph = new ChronoGraph(config);

// Create reactive variables
const x = graph.variableNamed('x', 10);
const y = graph.variableNamed('y', 20);

// Create computed value
const sum = graph.identifierNamed('sum', () => {
  return graph.readVariable(x) + graph.readVariable(y);
});

console.log(graph.readIdentifier(sum)); // 30

graph.writeVariable(x, 15);
console.log(graph.readIdentifier(sum)); // 35

// Undo/Redo
graph.undo();
console.log(graph.readIdentifier(sum)); // 30

Project Scheduling

import init, { WasmSchedulingEngine } from '@pmsite/chronograph';

await init();

const engine = new WasmSchedulingEngine();
engine.setProjectStart(Date.now());

// Add calendar with holidays
engine.addCalendar(1, 'Work Calendar');
engine.addCalendarException(1, {
  date: 1703462400000,
  is_working: false,
  name: 'Christmas'
});
engine.setProjectCalendar(1);

// Add tasks
engine.addTask({ id: 1, name: 'Design', duration: 432000000 });
engine.addTask({ id: 2, name: 'Development', duration: 864000000 });

// Add dependency
engine.addDependency({
  id: 1,
  predecessor_id: 1,
  successor_id: 2,
  dependency_type: 'FS'
});

// Calculate CPM (respects calendar)
engine.calculateCpmWithCalendar();

// Get results
const criticalPath = engine.getCriticalPath();
const stats = engine.getProjectStats();

Save and Load Projects

// Export project to JSON
const projectData = engine.exportProject();
localStorage.setItem('myProject', JSON.stringify(projectData));

// Import project from JSON
const saved = JSON.parse(localStorage.getItem('myProject'));
engine.importProject(saved);
engine.calculateCpmWithCalendar(); // Recalculate CPM after load

// Clear all project data
engine.clearProject();

Resource Shifts

Define shift patterns for resources to control their working hours:

// Define shifts
const morningShift = engine.addShift({
  id: 1,
  name: 'Morning Shift',
  intervals: [{ start_hour: 6, start_min: 0, end_hour: 14, end_min: 0 }]
});

const eveningShift = engine.addShift({
  id: 2,
  name: 'Evening Shift',
  intervals: [{ start_hour: 14, start_min: 0, end_hour: 22, end_min: 0 }]
});

// Add resource
engine.addResource({ id: 1, name: 'Worker', max_units: 100 });

// Assign shift pattern: Mon-Wed morning, Thu-Fri evening, weekends use calendar
engine.setResourceShiftPattern(1, [
  morningShift,   // Monday
  morningShift,   // Tuesday
  morningShift,   // Wednesday
  eveningShift,   // Thursday
  eveningShift,   // Friday
  null,           // Saturday (use calendar default)
  null            // Sunday (use calendar default)
]);

API Reference

See chronograph_api.md for complete API documentation.

Building from Source

# Install wasm-pack
cargo install wasm-pack

# Build WASM package
npm run build

# Run tests
npm test

License

Proprietary - All rights reserved