teleren/devto huggingface dataset:
How to create useEffect hook in vanilla JavaScript?
Published: 2024-02-15 14:30:36

Creating a `useEffect` hook equivalent in vanilla JavaScript involves understanding how to manage side effects when certain dependencies change. Here's a simplified example of how you could implement a basic version of `useEffect` in vanilla JavaScript:

```javascript
function useEffect(effect, dependencies) {
  // Initialize a variable to keep track of the previous dependencies
  let prevDependencies = [];

  // Check if the dependencies have changed since the last call
  const dependenciesChanged = () => {
    const changed = dependencies.some(
      (dependency, index) => dependency !== prevDependencies[index]
    );
    return changed;
  };

  // Run the effect function if there are no dependencies or if dependencies have changed
  if (!dependencies || dependenciesChanged()) {
    // Call the cleanup function from the previous effect (if any)
    if (typeof cleanup === 'function') cleanup();

    // Run the effect function
    const cleanup = effect();

    // Update the previous dependencies
    prevDependencies = dependencies;
  }
}
```

Here's how you can use this custom `useEffect` hook:

```javascript
// Usage example
let count = 0;

function render() {
  console.log(`Rendered with count: ${count}`);
}

function update() {
  count++;
  render();
}

// Define a side effect to run whenever `count` changes
useEffect(() => {
  console.log(`Count changed to: ${count}`);
}, [count]);

// Update the count
update();
```

In this implementation:

- The `useEffect` function takes two arguments: the effect function to run and an array of dependencies.
- It compares the current dependencies with the previous dependencies to determine if the effect needs to run again.
- If there are no dependencies or if dependencies have changed, it runs the effect function and updates the previous dependencies.
- It also provides a basic cleanup mechanism by calling the cleanup function from the previous effect (if any) before running the new effect.

This implementation is a simplified version of `useEffect` and doesn't cover all the features and optimizations present in React's `useEffect` hook, such as cleanup handling, timing of effect execution, and batching of updates. However, it demonstrates the basic idea of how you can create a simple side effect management hook in vanilla JavaScript.
How to create useState hook in vanilla JavaScript?
Published: 2024-02-15 14:29:45

To create a simplified version of the `useState` hook from React in vanilla JavaScript, you can leverage closures and JavaScript object destructuring. Here's a basic implementation:

```javascript
function useState(initialValue) {
  // Initialize the state variable with the provided initial value
  let state = initialValue;

  // Define a function to update the state
  function setState(newState) {
    state = newState;
    // Trigger re-rendering of the component (not implemented in this example)
    render();
  }

  // Return an array containing the current state and the function to update it
  return [state, setState];
}
```

Here's how you can use this custom `useState` hook:

```javascript
// Usage example
const [count, setCount] = useState(0);

// Increment the count
setCount(count + 1);

// Log the current state
console.log(count); // Output: 1
```

This `useState` implementation is simplified and lacks some features and optimizations present in React's `useState` hook, such as batching updates, lazy initialization, and preservation of state between re-renders. Additionally, it doesn't handle asynchronous updates or support functional updates (using a function as an argument to update the state based on the previous state). However, it demonstrates the basic idea of how you can create a simple state management hook in vanilla JavaScript.
How does React.js useState hook work under the hood?
Published: 2024-02-15 14:28:47

Under the hood, the `useState` hook leverages closures and a data structure managed by React to provide stateful behavior in functional components. Here's a simplified explanation of how `useState` works internally:

1. **Initialization**: When you call `useState(initialState)` in a functional component, React creates a "state variable" associated with that component. It allocates memory for storing the current state value and a reference to a function that can update that state.

2. **Component Instance**: Each time the component is rendered, React creates a new instance of the component. This instance includes the state variables and their associated updater functions.

3. **Persistent Identity**: React uses the component's identity (i.e., the reference to the function component itself) to maintain the association between the component instance and its state variables. This ensures that the state remains consistent across re-renders of the same component.

4. **State Updates**: When you call the state updater function (e.g., `setCount`), React schedules a re-render of the component with the new state value. React internally updates the state variable associated with the component instance.

5. **Batching Updates**: React batches multiple state updates that occur within the same event loop iteration to improve performance. This means that if you call `setCount` multiple times within the same function execution, React will only perform one re-render with the final state value.

6. **Lazy Initialization**: React initializes the state lazily. This means that the initial state value provided to `useState` is only evaluated during the initial render of the component, not on every render. Subsequent renders reuse the previously initialized state value.

7. **Preservation of State**: React ensures that state updates are preserved between re-renders of the component. Even if the component function is called multiple times (e.g., due to re-renders triggered by parent component updates), the state remains consistent because it's associated with the component instance.

Overall, the `useState` hook provides a simple and efficient way to introduce stateful behavior in functional components by leveraging closures and React's internal mechanisms for managing component instances and state updates. This abstraction allows developers to write declarative code without worrying about the underlying implementation details.
Errors occurred while using Vite
Tags: vite, react, errors
Published: 2024-02-15 14:27:31

---
title: Errors occurred while using Vite
published: true
description: 
tags: Vite,React,Error
---

## Here are some errors occurred while using Vite.

### 1. Error when create a new Vite project with the React template:

When running the command `npm install`, sometimes the terminal displays an error like the one shown in the picture:

![create new project.png](https://upload-images.jianshu.io/upload_images/3707284-74290db77d2099ef.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

Even though the log suggests using this command with `--force`, the error persists due to a permission issue. The correct way to resolve this error is to use the command with `sudo`.

![solve the error.png](https://upload-images.jianshu.io/upload_images/3707284-b5c471281afccbc6.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

Now, the error has been resolved, and the dependency is installed.
What is reconciliation process?
Published: 2024-02-15 14:26:53

The reconciliation process in React is the mechanism by which React determines which parts of the virtual DOM need to be updated based on changes in state or props, and efficiently applies those updates to the actual DOM. Reconciliation is a key part of React's declarative programming model, where you specify how your UI should look based on the current application state, and React takes care of updating the DOM to reflect those changes.

Here's an overview of how the reconciliation process works:

1. **Render Phase**: Whenever the state or props of a component change, React re-renders the component and its children in a virtual representation of the DOM called the "virtual DOM."

2. **Differential Algorithm**: React employs a "diffing" or "reconciliation" algorithm to compare the virtual DOM generated during the current render phase with the virtual DOM generated during the previous render phase. This process involves comparing each element of the virtual DOM tree and determining if any changes need to be applied to the actual DOM.

3. **Keyed Elements**: React uses keys assigned to each element in a collection (e.g., in lists or arrays of components) to efficiently identify which elements have been added, removed, or re-ordered since the last render. Keys help React determine the identity of elements across renders, ensuring that it can update the DOM efficiently without unnecessary re-renders or re-renders of unchanged elements.

4. **Minimal Updates**: React aims to minimize the number of updates required to bring the actual DOM into sync with the virtual DOM. Instead of re-rendering the entire component tree on each update, React selectively updates only the parts of the DOM that have changed. This approach improves performance by reducing the amount of work required to update the UI.

5. **Component Lifecycle Methods**: During the reconciliation process, React also invokes various component lifecycle methods, such as `componentDidMount`, `componentDidUpdate`, and `componentWillUnmount`, to allow components to perform side effects, update their internal state, or clean up resources as needed.

Overall, the reconciliation process in React plays a crucial role in ensuring that the UI remains in sync with the underlying application state while also optimizing performance by minimizing unnecessary updates to the DOM. By efficiently comparing virtual DOM trees and applying minimal updates to the actual DOM, React provides a fast and responsive user experience for web applications.
Badges.
Tags: devdiscuss, discuss, news
Published: 2024-02-15 14:26:24

Receive badges for being awesome! Click on a badge to see how you can earn it

https://dev.to/community-badges?badge=writing-debut


![Image badge](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/g26pxr0h9cha47we0or4.png)
What is Fiber architecture?
Published: 2024-02-15 14:25:40

The "Fiber" architecture in React is an internal implementation detail that significantly improves the performance and responsiveness of React applications by introducing a new reconciliation algorithm and scheduling mechanism.

Before the introduction of Fiber, React used a stack-based reconciliation algorithm, which could sometimes lead to performance bottlenecks, especially in large applications with complex component trees. The stack-based approach processed updates synchronously, which could result in long pauses during rendering, leading to janky user experiences.

The Fiber architecture introduces a new reconciliation algorithm and a virtual stack frame called "fiber" to manage the rendering process more efficiently. Here's an overview of how it works:

1. **Incremental Rendering**: Fiber enables React to break down the rendering work into smaller, incremental chunks. Instead of trying to complete the entire reconciliation in one go, React can split the work into smaller units and prioritize rendering updates based on their priority level and deadlines.

2. **Prioritization and Scheduling**: Fiber introduces a priority-based scheduling system, allowing React to prioritize different types of updates based on their importance. For example, React can prioritize rendering updates that are necessary for maintaining a smooth user experience (e.g., animations, user interactions) over less critical updates.

3. **Time Slicing**: Fiber implements a concept called "time slicing," which allows React to interrupt the rendering process and yield control back to the browser's event loop periodically. This ensures that the rendering work doesn't block the main thread for too long, preventing UI freezes and improving responsiveness.

4. **Concurrency**: Fiber enables concurrent rendering, allowing React to work on multiple tasks simultaneously. This concurrency model improves the utilization of available resources and can lead to faster rendering performance, especially on multi-core CPUs.

5. **Support for Suspense and Concurrent Mode**: The Fiber architecture provides the foundation for features like Suspense and Concurrent Mode in React. Suspense allows components to suspend rendering while waiting for asynchronous data to load, while Concurrent Mode enables React to render multiple components concurrently, further improving performance.

Overall, the Fiber architecture in React represents a significant evolution in how React handles rendering and updates. By introducing incremental rendering, prioritization, time slicing, and concurrency, Fiber improves the performance, responsiveness, and user experience of React applications, especially in modern web environments with demanding requirements.
How does React.js useEffect hook work behind the scene?
Published: 2024-02-15 14:23:25

The `useEffect` hook in React is a powerful tool that allows you to perform side effects in function components. Under the hood, React manages the lifecycle of function components using a mechanism called the "Fiber" architecture. When a function component is rendered or updated, React schedules these components for execution using a reconciliation process.

Here's how `useEffect` works under the hood:

1. **Initialization**: When a function component containing a `useEffect` hook is first rendered, React schedules the execution of the effect after the browser has painted the screen. This ensures that the UI is updated first before any side effects occur.

2. **Dependencies Tracking**: If the `useEffect` hook has a second argument - an array of dependencies, React compares the current values of these dependencies with their previous values (from the last render). React keeps track of these dependencies.

3. **Effect Execution**: If the dependencies have changed, React considers the effect to be "dirty" and executes it. If there are no dependencies (or no second argument is provided), the effect is executed after every render.

4. **Cleanup**: If the component is unmounted or the dependencies change, React performs cleanup before re-running the effect. This cleanup is especially useful for removing event listeners, subscriptions, or any other resources that might lead to memory leaks or stale data.

5. **Optimization**: React optimizes the execution of effects by batching multiple updates and only re-rendering components when necessary. It also ensures that effects are only executed when necessary, minimizing unnecessary side effects.

6. **Effect Dependencies Update**: If the dependencies array changes between renders, React re-evaluates the effect and performs the cleanup of the previous effect before running the new one. This ensures that the effect reflects the latest state of its dependencies.

Overall, `useEffect` provides a declarative way to manage side effects in React function components, allowing developers to write cleaner and more maintainable code. Its underlying implementation takes advantage of React's efficient rendering and reconciliation processes to ensure optimal performance.
Playtime Adventures: Toys and Games Galore
Published: 2024-02-15 14:23:20

At [Value Box](https://valuebox.pk/collections/toys-and-games), we believe in the transformative power of play. Our mission is simple: to provide you and your loved ones with an unparalleled selection of toys and games that inspire creativity, encourage exploration, and ignite the imagination.

Unlocking the World of Play

Value Box isn't just a store; it's a gateway to endless adventures and unforgettable memories. Step into our virtual aisles and discover a treasure trove of toys and games that cater to every age, interest, and personality. Whether you're a parent searching for educational toys to stimulate your child's development or a gamer seeking the latest entertainment, we have something special waiting just for you.

From Classic Favorites to Modern Marvels

From timeless classics like board games and building blocks to cutting-edge tech toys and immersive gaming experiences, our diverse selection ensures that there's something for everyone. Rediscover the joy of family game nights with beloved favorites like Monopoly, Scrabble, and Uno. Dive into the world of make-believe with imaginative playsets and action figures. Immerse yourself in virtual worlds with state-of-the-art gaming consoles and accessories.

Quality and Safety You Can Trust

At Value Box, quality and safety are our top priorities. We partner with trusted brands and manufacturers to bring you products that meet the highest standards of craftsmanship and durability. From durable materials to rigorous safety testing, we go above and beyond to ensure that every toy and game in our collection is built to last and safe for all ages.

The Value Box Promise

When you shop with us, you're not just purchasing toys and games; you're investing in moments of joy, laughter, and connection. Whether you're shopping for a special occasion or simply looking to brighten someone's day, we're here to make every playtime experience extraordinary.
Earthquake Heatmap using Python folium library
Tags: python, datascience, webscraping, web
Published: 2024-02-15 14:04:06

[https://github.com/gokayburuc/koeri-heatmap](https://github.com/gokayburuc/koeri-heatmap)


## Introduction 

This project was developed to create an earthquake heat map using python folium, bs4, requests and pandas libraries. It is open source and not for commercial purposes.

Earthquake source data was taken from [http://www.koeri.boun.edu.tr/scripts/lst0.asp](http://www.koeri.boun.edu.tr/scripts/lst0.asp).

When the project runs, an  `output.html`   file is displayed on the screen in the browser.

## Screenshots

![View1](https://raw.githubusercontent.com/gokayburuc/koeri-heatmap/main/img/1.png)
![View2](https://raw.githubusercontent.com/gokayburuc/koeri-heatmap/main/img/2.png)

## Resources

The official documents I used in this projects are shared below: 

- [Folium](https://python-visualization.github.io/folium/index.html)
- [Heatmap](https://python-visualization.github.io/folium/plugins.html?highlight=heatmap#folium.plugins.HeatMap)

## Location Info

In order to create a heatmap on Folium, map boundaries were obtained from the following web page as geolocation.

[LocationInfo](https://www.distancesto.com/coordinates/tr/turkey-latitude-longitude/history/3603.html)

| Location Term     | Value              |
| ----------------- | ------------------ |
| Turkey Latitude:  | 38.963745          |
| Turkey Longitude: | 35.243322000000035 |

## Requirements 

Required Libraries are: 

- [folium](https://python-visualization.github.io/folium/latest/)
- [bs4](https://beautiful-soup-4.readthedocs.io/en/latest/)
- [requests](https://requests.readthedocs.io/en/latest/)
- [rich](https://github.com/Textualize/rich)
- [pandas](https://pandas.pydata.org/)

## Usage

When you run the file below, the necessary Python libraries will be installed automatically. Afterwards, data will be extracted from the page and a file named `output.html` will be created. `output.html` will open and the earthquake heatmap page will appear on your screen.


```bash 
bash koeri.sh 
```

## Reach Me 

How to reach me : [gokayburuc@yandex.com](mailto:gokayburuc@yandex.com)
Disposability - The Twelve Factor App Methodology
Tags: beginners, tutorial, cloud, architecture
Published: 2024-02-15 14:00:00

Welcome back to our journey through the Twelve Factors in Software Development. In this segment, we'll explore Factor 9: Disposability. This factor introduces the concept of treating processes as disposable entities and highlights how it contributes to the resilience and reliability of your application.

## Disposability: Maximize Robustness with Quick Startup and Shutdown
The Disposability factor encourages the design of applications that can start and stop quickly. Treating processes as disposable entities means that individual components of your application can be easily and rapidly replaced, contributing to fault tolerance and responsiveness.

## Why It Matters
In cloud-native environments, the ability to quickly start and stop processes is crucial for maintaining high availability and responding to dynamic workloads. Disposable processes contribute to easier scaling, resilience to failures, and efficient resource utilization.

## How to Implement
Design your application with the understanding that processes may need to start and stop frequently. Ensure that startup times are minimal and that processes can gracefully shut down when needed. This is particularly relevant in containerized environments and orchestration systems like Kubernetes.

## Example in Action
Consider a scenario where your application needs to process messages from a queue. Instead of having a long-lived process, design your application to spin up short-lived worker processes to handle each message. This approach ensures that resources are efficiently used, and failures are isolated.

```js
// Listen for messages in a queue
queue.on('message', (message) => {
  // Start a transaction you can rollback
  startTransaction(message);

  // Process
  processMessage(message);

  // Commit
  commitTransaction(message);
});

process.on('SIGTERM', async () => {
  console.log('Received SIGTERM. Rolling back transaction and closing connections.');
  await rollbackTransaction(message);
  await bringMessageBackInQueue(message);
  await closeConnection();
  process.exit(0);
});
```

By embracing the Disposability factor, your application becomes more robust, resilient, and capable of handling varying workloads and failures gracefully.

Stay tuned for Factor 10: Dev/Prod Parity, where we'll explore the importance of maintaining similarity between development and production environments for a smoother development and deployment process.