The post "JavaScript Views, the Hard Way" details a pattern for structuring JavaScript UI code using simple functions called "views." These views take data as input and return HTML strings as output, promoting separation of concerns between logic and presentation. The pattern emphasizes immutability by treating views as pure functions and managing state changes externally. It encourages composing complex UIs from smaller, reusable view functions, simplifying development and testing. While avoiding frameworks, this approach provides a structured way to organize UI code, making it more maintainable and predictable, especially for smaller projects where the overhead of a full framework might be unnecessary. The core concept involves rendering views based on data and updating the DOM only when the data changes, leading to a potentially more efficient rendering process.
This GitHub repository, titled "JavaScript Views, the Hard Way," explores a specific pattern for structuring JavaScript user interface (UI) code, emphasizing explicit management of DOM elements and their associated data. Instead of relying on frameworks or libraries that abstract away DOM manipulation, this approach champions a more direct, granular level of control, potentially leading to improved performance in certain scenarios and offering a deeper understanding of how UI elements interact with JavaScript logic.
The core idea revolves around creating distinct "view" objects. Each view object is responsible for a specific section of the DOM. It encapsulates the logic for creating, updating, and removing the associated DOM elements, as well as managing the data that those elements represent. This separation of concerns promotes code organization and maintainability, particularly in complex UI structures.
Crucially, the pattern emphasizes avoiding direct manipulation of the DOM outside of the view object's methods. When data changes, the view object's update method is called, which efficiently reconciles the current state of the DOM with the new data. This targeted approach to DOM manipulation can minimize unnecessary reflows and repaints, leading to potential performance gains, especially in applications with frequent updates.
The "hard way" moniker refers to the increased verbosity and manual effort involved in managing DOM elements directly. While frameworks often provide declarative ways to describe the UI and automatically handle updates, this pattern requires explicit coding of DOM operations. However, this explicitness can provide greater transparency and control over the UI's behavior and performance characteristics.
The repository demonstrates this pattern with a practical example – building a simple to-do list application. This example illustrates how to create view objects for individual to-do items and how to manage the overall list structure using a parent view object. The code showcases techniques for efficiently updating the DOM when items are added, removed, or modified, highlighting the benefits of this more direct approach to UI development. By walking through this concrete example, the repository aims to provide a clear understanding of the pattern's principles and its potential advantages in specific situations where fine-grained control and performance optimization are paramount.
Summary of Comments ( 96 )
https://news.ycombinator.com/item?id=43733636
Hacker News users generally praised the article's approach to building UI components in JavaScript without a framework. Several commenters appreciated the focus on fundamental DOM manipulation and the clear explanation of how to manage state and updates efficiently. The simplicity and educational value were highlighted, with some suggesting it as a good resource for beginners. A few mentioned potential drawbacks, like the verbosity compared to framework-based solutions, and the lack of certain conveniences frameworks offer. However, the prevailing sentiment was that the article provided a valuable, back-to-basics perspective on UI development. Some discussion arose around alternative approaches and the merits of using frameworks, but the core value of understanding the underlying principles was consistently acknowledged.
The Hacker News post discussing "JavaScript Views, the Hard Way – A Pattern for Writing UI" has a moderate number of comments exploring various aspects of the presented pattern.
Several commenters appreciate the author's approach to structuring UI code, particularly praising its explicitness and separation of concerns. They find the clear delineation between data, logic, and presentation beneficial for maintainability and understandability, contrasting it with the perceived magic often found in modern frameworks. The explicit rendering loop is highlighted as a valuable learning tool for understanding how UI updates work under the hood.
Some commenters draw parallels and contrasts with other UI architectures and libraries. Comparisons are made to React, highlighting the differences in data flow and component lifecycle management. The discussion also touches on the tradeoffs between this explicit approach and the declarative style popularized by frameworks like React and Vue.js. Some argue that while the proposed pattern is educational, the verbosity might become cumbersome for larger projects.
The concept of "views" as functions is discussed, with some suggesting alternative terminology like "components" to better align with established conventions. The potential benefits and drawbacks of using a dedicated view object versus plain functions are also explored.
Performance concerns are raised regarding the potential overhead of the rendering loop compared to optimized diffing algorithms used in virtual DOM libraries. However, counterarguments suggest that for many applications, this overhead might be negligible and the explicit rendering could even offer optimization opportunities in specific scenarios.
A few commenters express interest in seeing the pattern applied to more complex examples, showcasing its scalability and practicality in real-world scenarios. Others share their own experiences and preferences regarding UI architecture, contributing to a broader discussion on the merits of different approaches.
Finally, there's a minor thread discussing the chosen example (a todo list) and suggesting alternative examples that might better demonstrate the pattern's capabilities.