Migration Guide Overview

Welcome to the migration guide for upgrading from ng2-pdfjs-viewer v20.x to v25.x. This guide will help you smoothly transition to the new architecture.

Why Migrate to v25.x?

Version 25.x represents a complete rewrite with significant improvements:

🚀 Major Improvements

• Modern Architecture: Event-driven design with universal action dispatcher
• Better Performance: No timeouts, polling, or defensive programming
• Enhanced Security: Template-based UI instead of HTML strings
• Improved DX: Better TypeScript support and cleaner API
• Mobile-First: Responsive design optimized for all devices
• Production-Ready: Comprehensive error handling and testing

📊 Before vs After

Aspect	v20.x	v25.x
Architecture	Mixed event/polling	Pure event-driven
Customization	HTML strings	Angular templates
Error Handling	Basic	Comprehensive
TypeScript	Partial	Strict mode
Mobile Support	Limited	Mobile-first
Performance	Good	Excellent

Migration Strategy

1. Assessment Phase

• Review your current implementation
• Identify breaking changes that affect you
• Plan the migration timeline

2. Preparation Phase

• Update to Angular 20+ (recommended)
• Backup your current implementation
• Review new features you want to adopt

3. Migration Phase

• Update package version
• Apply breaking changes fixes
• Test thoroughly

4. Enhancement Phase

• Adopt new features
• Optimize performance
• Improve user experience

Breaking Changes Summary

warning

v25.x introduces several breaking changes. Review each section carefully.

1. Template-Based UI

Old (v20.x):

// HTML strings (deprecated)
this.pdfViewer.setErrorHtml('<div>Error occurred</div>');
this.pdfViewer.setSpinnerHtml('<div>Loading...</div>');

New (v25.x):

<!-- Angular templates -->
<ng-template #errorTemplate>
  <div>Error occurred</div>
</ng-template>

<ng2-pdfjs-viewer [customErrorTpl]="errorTemplate">
</ng2-pdfjs-viewer>

2. Property Renames

Old Property	New Property	Notes
[startDownload]	[downloadOnLoad]	Clearer naming
[startPrint]	[printOnLoad]	Clearer naming
[errorHtml]	[customErrorTpl]	Template-based
[spinnerHtml]	[customSpinnerTpl]	Template-based

3. Event System Updates

Old (v20.x):

// Limited events
(onDocumentLoad)="onLoad()"
(onDocumentError)="onError($event)"

New (v25.x):

// 24+ comprehensive events
(onDocumentLoad)="onLoad()"
(onDocumentError)="onError($event)"
(onPageChange)="onPageChange($event)"
(onProgress)="onProgress($event)"
// ... and many more

4. Configuration Objects

Old (v20.x):

// Individual properties
[showToolbar]="true"
[showSidebar]="true"
[showDownload]="true"
[showPrint]="true"

New (v25.x):

// Grouped configuration objects
[groupVisibility]="groupVisibilityConfig"
[controlVisibility]="controlVisibilityConfig"

// Where:
groupVisibilityConfig = {
  download: true,
  print: true,
  find: true,
  fullScreen: true
};

Migration Timeline

Immediate (Required)

1. Update package version
2. Fix breaking changes
3. Update deprecated properties
4. Test basic functionality

Short-term (Recommended)

1. Migrate to templates
2. Adopt configuration objects
3. Implement new events
4. Update error handling

Long-term (Optional)

1. Adopt new theming system
2. Implement mobile optimizations
3. Enhance user experience
4. Performance optimizations

Migration Tools

Automated Migration (Coming Soon)

We're working on an automated migration tool to help with common changes:

# Future release
npx ng2-pdfjs-viewer-migrate

Manual Migration Checklist

• Update package version
• Replace deprecated properties
• Convert HTML strings to templates
• Update event handlers
• Test all functionality
• Update documentation

Testing Strategy

1. Unit Tests

Update your unit tests to work with the new API:

// Old test approach
it('should set error HTML', () => {
  component.pdfViewer.setErrorHtml('<div>Error</div>');
  // ... test assertions
});

// New test approach
it('should use error template', () => {
  component.errorTemplate = mockTemplate;
  // ... test assertions
});

2. Integration Tests

Test the complete PDF viewing workflow:

it('should load PDF and handle events', async () => {
  const loadSpy = jasmine.createSpy('onDocumentLoad');
  component.onDocumentLoad = loadSpy;
  
  component.pdfSrc = 'test.pdf';
  await fixture.detectChanges();
  
  expect(loadSpy).toHaveBeenCalled();
});

3. E2E Tests

Ensure the viewer works correctly in real browsers:

it('should display PDF correctly', () => {
  cy.visit('/pdf-viewer');
  cy.get('ng2-pdfjs-viewer').should('be.visible');
  cy.get('.pdf-page').should('exist');
});

Support During Migration

Resources

• 🚀 Getting Started - Set up v25.x quickly
• 📚 Examples - Practical code examples
• 🎯 Live Demo - See v25.x in action

Community Support

• 💬 GitHub Discussions - Ask questions
• 🐛 GitHub Issues - Report migration issues
• 📖 Documentation - Complete documentation

Professional Support

Need help with your migration? Consider:

• Code review services
• Migration consulting
• Training sessions
• Custom implementation

Next Steps

Ready to start your migration?

1. 🚀 Getting Started - Set up v25.x
2. 📚 Examples - Learn new patterns
3. 📖 API Reference - Complete API documentation
4. 🎨 Theming Guide - Customize appearance

Migration Success Stories

Success Story

"The migration to v25.x took us 2 days and improved our app's performance significantly. The new event system is much more reliable." - Enterprise Customer

Success Story

"Template-based error handling is a game-changer. Our custom error pages look and feel native to our app." - SaaS Platform

Start your migration journey today and unlock the full potential of ng2-pdfjs-viewer v25.x!