Building a Rich Text Editor

Architecture, core concepts, and technologies needed to build a robust rich text editor. Understanding model-view separation, schema design, and position management.

Overview

Building a rich text editor is more than just working with contenteditable. It requires understanding document models, schema design, position management, and the separation between your internal data model and the DOM representation.

Modern editors like ProseMirror, Slate, and Lexical all follow similar architectural patterns that separate concerns and make editors maintainable and extensible.

Key Principle: Model-View Separation

The fundamental principle is separating the document model (your internal representation) from the view (the DOM). The model is your source of truth, and the view is just a projection.

  • Model: Abstract, schema-validated, framework-agnostic
  • View: HTML representation, handles user input, browser-specific

Core Concepts

Document Model

Your internal representation of the document. Tree structure with nodes (blocks, inlines, text) and marks (formatting).

Learn more →

Schema

Defines what your document can contain: node types, content rules, attributes, and marks.

Learn more →

Position Management

Representing positions in your model using paths (array of indices) instead of DOM references.

Learn more →

HTML Mapping

Converting between your model and HTML: serialization (model → HTML) and deserialization (HTML → model).

Learn more →

Detailed Guides

Editor Architecture

Model-view separation, document model structure, view layer responsibilities, and how they work together.

  • Why separate model and view
  • Document model structure
  • View layer responsibilities
  • State management patterns

Model & Schema

Designing your document model and schema: node types, document structure, mark system, and validation.

Position & Selection Management

Managing positions and selections in your model: path-based positions, selection representation, and DOM conversion.

  • Path-based position representation
  • Model selection structure
  • DOM to model conversion
  • Model to DOM conversion
  • Selection normalization

HTML Mapping

Converting between your model and HTML: serialization, deserialization, and incremental updates.

  • Model to HTML serialization
  • HTML to model deserialization
  • Handling edge cases
  • Incremental DOM updates
  • Preserving marks and attributes

Model-DOM Synchronization

Keeping your model and DOM in sync: handling contenteditable=false, preserving selection, and managing updates.

  • Bidirectional synchronization
  • contenteditable=false handling
  • Selection preservation
  • Update strategies

History Management

Implementing undo/redo functionality: model-based history, conflict resolution, and DOM history handling.

  • Model-based history
  • DOM history conflicts
  • Undo/redo implementation
  • History state management

Input Handling & IME

Comprehensive guide to handling user input, IME composition, keyboard events, and text processing.

  • IME composition handling
  • Keyboard event processing
  • Text input normalization
  • Paste operation handling
  • Mobile input support

Plugin Development

Guide to developing plugins that extend model-based contenteditable editors with custom functionality.

  • Plugin architecture
  • Plugin lifecycle
  • Using hooks and commands
  • Plugin examples

Testing Strategies

Comprehensive testing strategies for model-based contenteditable editors at different levels.

  • Unit testing
  • Integration testing
  • IME testing
  • End-to-end testing
  • Mobile testing

Debugging Techniques

Debugging strategies and techniques for contenteditable editors, including tools and common issues.

  • Debugging tools
  • Event logging
  • Common issues
  • Performance debugging

Mobile Support

Guide to supporting mobile devices in contenteditable editors, including virtual keyboards and touch interactions.

  • Virtual keyboard handling
  • Touch selection
  • Mobile input handling
  • iOS/Android specific issues

Accessibility

Accessibility considerations and best practices for contenteditable editors, including screen reader support and ARIA attributes.

  • Screen reader support
  • ARIA attributes
  • Keyboard navigation
  • Focus management
  • Live announcements

Transaction System

Using transactions to group operations into atomic units for consistent history management in model-based editors.

  • Atomic history entries
  • Transaction lifecycle
  • History integration
  • Transaction patterns
  • Nested transactions

Operations

Comprehensive guide to operation types that can be combined in transactions for model-based editors.

  • Insert operations
  • Delete operations
  • Format operations
  • Replace and move operations
  • Operation inversion

Getting Started

Recommended learning path:

  1. Start with Architecture: Understand model-view separation and why it's important
    → Read Editor Architecture
  2. Learn Model & Schema: Design your document structure and validation rules
    → Read Model & Schema
  3. Master Position & Selection: Understand how to represent and manage positions in your model
    → Read Position & Selection
  4. Implement HTML Mapping: Build serialization and deserialization between model and HTML
    → Read HTML Mapping
  5. Add contenteditable APIs: Use Selection API, Range API, and events in your view layer
    → Browse Documentation

All Documentation

Related Resources