The Hard Parts of UI Development

• Understand the Fundamentals of UI Development: Learn how to keep the user interface in sync with application data using JavaScript and browser features like the DOM and HTML parser.
• Master Data Binding and UI Composition: Gain a deep understanding of data binding techniques and UI composition to create responsive and interactive web applications.
• Explore Virtual DOM and Reconciliation: Learn how the virtual DOM works, how it improves performance, and how reconciliation processes optimize rendering.
• Develop UI from Scratch: Build user interfaces without relying on frameworks, gaining a comprehensive understanding of the underlying principles and mechanics.
• Implement Hooks and Reactive Programming: Learn how to use hooks to tap into existing systems and create reactive, efficient applications.
• Create a Mental Model for UI Development: Develop a complete mental model of UI development that can be applied to any framework or library.

In "The Hard Parts of UI Development," Will Sentance takes you on an in-depth journey through the complexities of building user interfaces in web applications. You'll start with the basics of how user interfaces display content and manage data binding, then progress to advanced topics like virtual DOM and reconciliation. Throughout the course, you'll learn to build UI components from scratch, gaining a deep understanding of the mechanics behind popular frameworks like React, Angular, and Vue. By the end of this course, you'll have a comprehensive mental model of UI development that you can apply to any project.

• Frontend developers looking to deepen their understanding of UI development.
• Software engineers interested in the mechanics behind popular UI frameworks.
• JavaScript developers seeking to build more efficient and responsive web applications.
• Anyone curious about the underlying principles of modern UI development.

• Basic JavaScript Knowledge: Familiarity with JavaScript syntax and basic programming concepts is recommended.
• Interest in UI Development: A desire to learn about the complexities and mechanics of building user interfaces.

Introduction

Learn about the course goals, including understanding UI display content, data binding, virtual DOM, and reconciliation, along with core engineering principles.

State & View

• User Interface Dev Overview: Explore the role of visual interfaces in technology and how they allow users to interact with content and data.
• Display Content: Learn how programming languages model content for display and how the Document Object Model (DOM) represents this content.
• Rendering HTML Under the Hood: Understand how HTML is rendered in browsers as C++ objects and displayed on the screen.
• CSSOM for Styling: Discover how the CSS Object Model (CSSOM) represents styling instructions in a similar way to the DOM.
• Enabling Change of Content: Learn how user interactions trigger data changes, prompting the rendering engine to update the UI.

JavaScript, DOM & Events

• Storing Data in JavaScript: Diagram the relationship between HTML parsing, the browser, and the JavaScript engine for dynamic content updates.
• WebIDL & WebCore: Understand how WebCore and WebIDL provide access to the DOM for JavaScript, enabling pixel-level data display.
• Updating DOM Elements with JavaScript: Explore how JavaScript APIs interact with the C++ DOM list via WebIDL to update page content.
• Handling User Interaction Overview: Learn how JavaScript interacts with the DOM to handle user interactions and update content.
• Understanding the handleInput Function: Diagram memory allocation for event handlers and how user-triggered events invoke callbacks.
• User Interaction & DOM Updates: Understand how JavaScript functions update DOM elements in response to user input.

Data-Binding in the UI

• One-Way Data Binding: Discover one-way data binding as a paradigm for maintaining UI consistency with underlying data.
• Changing View Based on User Interaction: Learn how JavaScript mutates DOM data, updating the UI as users interact with elements.
• Handling Multiple User Interactions: Diagram data flow for multiple user interactions and how JavaScript manages these changes.
• Separating Data & View Updates: Understand the benefits of decoupling data changes from view updates for maintainable code.
• Predictable Data & View Flow: Summarize predictable data and view flows, creating a reliable pattern for UI updates.

Virtual DOM

• Virtual DOM Introduction: Explore how the virtual DOM stores visual representations of UI elements, allowing efficient updates.
• Auto-Updating Views UI: Learn to use setInterval for automatic UI updates, keeping the UI in sync with data changes.
• Understanding UI Components: Discover UI components as functions that create elements and manage data-view binding.
• Emulate HTML with String Interpolation: Use string interpolation for clearer code that reflects visual screen elements.
• Creating a JavaScript Virtual DOM: Create a virtual DOM in JavaScript, handling user input and dynamically updating the UI.

Composition & Functional Components

• Using Lists for UI Development: Understand the benefits of using lists to decouple code execution from UI elements.
• Composable Code with Map and Spread: Learn to create flexible virtual DOMs using array methods for efficient rendering.
• Event API: Explore the Event API for accessing properties like mouse position and creating flexible event handling code.

Performance Improvements

• Update the DOM on Data Change: Refactor code for automatic UI updates, ensuring data and UI consistency.
• Automatic Updates with Hooks: Introduce hooks for modifying system behavior and enhancing application extensibility.
• Performance Gains Using Diffing: Use diffing algorithms to improve performance by updating only changed DOM elements.

Wrapping Up

Conclude the course with a summary of the UI approaches learned, emphasizing a single source of truth for data, UI composition, and VDOM diffing for efficiency.