Fat Components vs. Fat Pages in React: Choosing the Right Approach
Tags: react, components, frontend
Published: 2023-09-27 16:07:26

---
title: Fat Components vs. Fat Pages in React: Choosing the Right Approach
published: true
date: 2023-09-26 23:49:48 UTC
tags: reactjs,components,frontenddevelopment,react
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---

![](https://cdn-images-1.medium.com/max/1024/0*OgGKsY75iVDwMGvc)
_Photo by Kadarius Seegars on Unsplash_

**Introduction:**  
When it comes to organizing logic in React, developers have two prominent approaches: fat components and fat pages. Imagine fat components as all-in-one powerhouses, handling significant logic within themselves, while fat pages delegate substantial logic to components, focusing on rendering the UI. In this article, we’ll explore the pros and cons of each approach, provide practical examples, and discuss the factors to consider when deciding which approach suits your project best.

**Comparison: Fat Components vs. Fat Pages Through the Lens of Moving Houses**  
To understand the distinction, let’s draw an analogy. Imagine you’re moving houses. Fat components can be likened to putting your things into boxes and neatly organizing everything in one place. It simplifies the moving process, making it easier to manage. On the other hand, fat pages are comparable to buying new stuff each time you move. While it may appear convenient initially, it can lead to redundancy and unnecessary complexity in the long run.

**Advantages of Fat Components:**

- Easier to reason about as all the logic resides in one place. A fat component encapsulates everything it needs to make its magic happen.
- Increased reusability by extracting common logic into separate components. You can create reusable building blocks that sprinkle their logic across your application.

**Disadvantages of Fat Components:**

- Maintenance challenges as components grow in size and complexity. Over time, a fat component might become harder to understand, debug, and maintain, especially when it juggles multiple responsibilities.
- Potential performance impact as components trigger re-renders upon state changes. Frequent state updates in a fat component can lead to unnecessary re-renders, potentially affecting your application’s overall performance.

**Advantages of Fat Pages:**

- Enhanced efficiency as the logic executes once for the entire page. Fat pages can leverage caching mechanisms, optimizing data fetching and computations for superior performance.
- Improved clarity as logic is shared across multiple components. By distributing logic across different components, each component can focus on its specific responsibility, resulting in a modular and comprehensible codebase.

**Disadvantages of Fat Pages:**

- Increased maintenance complexity due to logic spread across multiple components. Spreading logic across different components can make it trickier to trace and comprehend the flow of data and actions.
- Reduced reusability as the logic becomes more page-specific. Since fat pages often encompass page-specific logic, it may limit the reusability of the components within those pages.

**Single Responsibility Principle and Its Impact on Logic Organization**

One crucial principle to consider when organizing logic in React is the Single Responsibility Principle (SRP). The SRP states that a component or module should have only one reason to change. Applying this principle helps to create more maintainable and scalable codebases. Let’s explore how the SRP aligns with the concepts of fat components and fat pages.

**SRP and Fat Components:**  
Fat components inherently run the risk of violating the SRP. As a component grows in size and complexity, it becomes challenging to adhere to a single responsibility. The logic within a fat component may become entangled, making it harder to identify and modify specific functionalities. Therefore, when using fat components, it’s crucial to be mindful of keeping each component focused on a single responsibility.

**SRP and Fat Pages:**  
Fat pages, by distributing logic across multiple components, can align more easily with the SRP. Each component within a fat page can focus on a specific responsibility, ensuring a modular and maintainable codebase. With this approach, it becomes easier to identify and modify the logic associated with a particular functionality without affecting the entire page.

**Factors to Consider When Deciding between Fat Components and Fat Pages:**

1. Scalability: Fat pages can be more scalable since they only require re-rendering when the data they are rendering changes. In contrast, fat components need to be re-rendered whenever their state changes.

2. Maintainability: Fat pages can be more challenging to maintain as the logic is spread across multiple components, making understanding and debugging more difficult. Fat components, on the other hand, contain all the logic for a component, making them easier to understand and maintain.

3. Performance: Fat pages can be more performant as they only need to be re-rendered when the data they render changes, while fat components require re-rendering whenever their state changes.

**Tips for Choosing Between Fat Components and Fat Pages:**

1. Start with fat components, especially for new projects or teams, as they are easier to understand and maintain.

2. Encapsulate repeated logic into fat components to improve code reusability and maintenance.

3. Transition fat components to fat pages as needed for improved efficiency and scalability, considering bottlenecks or performance issues as triggers.

4. Consider your team’s experience and project timeline. If your team is new to React or you have tight deadlines, fat pages may be a better option.

5. Evaluate project requirements. If scalability or performance is crucial, consider choosing fat pages or a combination of fat components and fat pages.

**Choosing the Right Approach:**

To strike a balance between fat components and fat pages, it is crucial to consider the size and complexity of your project. For smaller projects or when starting out, fat components offer simplicity and reusability. As your project grows, transitioning to fat pages can improve efficiency and maintainability, aligning with the Single Responsibility Principle.

**Conclusion:**

Ultimately, the choice between fat components and fat pages in React depends on your project’s requirements, team dynamics, and long-term goals. By considering scalability, maintainability, and performance, you can make an informed decision that best suits your specific situation. Remember to evaluate the advantages and disadvantages of each approach and adjust as needed to create a robust and efficient React application.

**✨Bonus: Creating a Complex Select Component with the Single Responsibility Principle**

Let’s apply the Single Responsibility Principle to a practical example: a complex select component. By breaking down the select component into smaller, focused components, we adhere to the SRP. Each component handles a specific responsibility, making the codebase more modular and maintainable.

```javascript
// SelectInput.js
// Responsible for rendering the select input UI

import React from 'react';

const SelectInput = ({ options, onChange }) => {
  return (
    <select onChange={onChange}>
      {options.map((option) => (
        <option key={option.value} value={option.value}>
          {option.label}
        </option>
      ))}
    </select>
  );
};

export default SelectInput;
```
```javascript
// SelectValidator.js
// Responsible for validating the selected option

const SelectValidator = (selectedValue) => {
  // Validation logic here
  return isValid;
};

export default SelectValidator;
```
```javascript
// SelectFetcher.js
// Responsible for fetching data for select options

const SelectFetcher = () => {
  // Data fetching logic here
  return options;
};

export default SelectFetcher;
```
```javascript
// SelectComponent.js
// The main select component that brings everything together

import React, { useState, useEffect } from 'react';
import SelectInput from './SelectInput';
import SelectValidator from './SelectValidator';
import SelectFetcher from './SelectFetcher';

const SelectComponent = () => {
  const [selectedValue, setSelectedValue] = useState('');
  const [options, setOptions] = useState([]);

  useEffect(() => {
    const fetchData = async () => {
      const fetchedOptions = await SelectFetcher();
      setOptions(fetchedOptions);
    };

    fetchData();
  }, []);

  const handleChange = (event) => {
    setSelectedValue(event.target.value);
  };

  const isValid = SelectValidator(selectedValue);

  return (
    <div>
      <SelectInput options={options} onChange={handleChange} />
      {isValid ? null : <p>Please select a valid option.</p>}
    </div>
  );
};

export default SelectComponent;
```

By following this approach, we can easily modify and extend the functionality of the select component without affecting other parts of the application. This example demonstrates how applying the SRP can lead to more manageable and scalable codebases.

Finally, whether you choose fat components or fat pages, or a combination of both, keep the Single Responsibility Principle in mind. Strive for modular, maintainable, and scalable code that aligns with your project’s needs. Experiment, learn, and adapt your approach as your project evolves, ensuring an efficient and enjoyable development experience in React.