Ruthie  Blanda

Ruthie Blanda

1660260720

Tiny Logger: A Magical React Hook That Helps You Debug Components

useTilg

Tiny Logger is a magical React Hook to help you debug your components.

You can quickly try out the demo.

Installation

The package is released as tilg, use:

npm i tilg

to install it with npm. Or you can choose another package manager.


 

Features

1. Lifecycle Events (What)

Simply insert the useTilg() hook into the component, and it will log the render, mount, unmount events in the console:

import useTilg from 'tilg'

function MyButton() {
  useTilg()
  return <button>Click me</button>
}

lifecycle event logs 
Logs of render and mount events.

2. Component Name and Props (Who)

You might noticed that it also displays the name and props of the component, which is very helpful for debugging.

import useTilg from 'tilg'

function MyButton({ text }) {
  useTilg()
  return <button>{text}</button>
}

function Title({ children }) {
  useTilg()
  return <h1>{children}</h1>
}

export default function Page() {
  return (
    <>
      <Title>Welcome!</Title>
      <MyButton text='foo' />
      <MyButton text='bar' />
    </>
  )
}

When there’re multiple elements of the same component being rendered, it adds a counter <MyButton/> (2) for distinguishing so you know who is logging the information:

information logs 
Information of the logged components.

3. Debug Message (Why)

Another critical thing is to know why does a component re-renders. useTilg gives you a simple but powerful API for this:

import { useState } from 'react'
import useTilg from 'tilg'

function Counter() {
  const [count, setCount] = useState(0)
  
  useTilg()`count = ${count}`
  
  return <button onClick={() => setCount(count + 1)}>{count}</button>
}

When appending a template literal to the useTilg() call, it will also be displayed as the debug message:

useTilg()`count = ${count}`

debug message 
Logs of “count = ?”.

You can know where the message is from, too:

trace 
Trace of the message and a link to the code location.

4. What Has Changed? (Why)

Something troubles me a lot when debugging a component is, it’s sometimes hard to know which state has changed and triggered a re-render. useTilg tracks all the arguments in the debug message and tells you which one has changed since the previous render:

import { useState } from 'react'
import useTilg from 'tilg'

function MyApp() {
  const [input, setInput] = useState('')
  const [count, setCount] = useState(0)

  useTilg()`input = ${input}, count = ${count}`

  return (
    <>
      <input onChange={(e) => setInput(e.target.value)} value={input} />
      <button onClick={() => setCount(count + 1)}>{count}</button>
    </>
  )
}

changed argument 
A hint for the updated part.

5. Quick Logs (Why)

If you don't need a debug message but only want to quickly log some values, just pass them to the hook directly:

import { useState } from 'react'
import useTilg from 'tilg'

function MyApp() {
  const [input, setInput] = useState('')
  const [count, setCount] = useState(0)

  useTilg(input, count)

  return (
    <>
      <input onChange={(e) => setInput(e.target.value)} value={input} />
      <button onClick={() => setCount(count + 1)}>{count}</button>
    </>
  )
}

value without message 
Debug values quickly.


 

Advanced Features

Markdown

You can use Markdown's code (`), italic (_ or *), and bold (__ or **) syntax in your debug message to make it look nicer:

function MyApp() {
  const [count, setCount] = useState(0)

  useTilg()`**Debug**: \`count\` = _${count}_.`

  return <button onClick={() => setCount(count + 1)}>{count}</button>
}

markdown syntax 
Markdown syntax in log messages.

Return Original Value

The useTilg() hook also returns its first argument, or the first value in the template if specified, so you can quickly debug something in-place by wrapping it with useTilg():

  function MyApp() {
    const [count, setCount] = useState(0)

    return <button onClick={() => setCount(count + 1)}>{
+     useTilg(count)
    }</button>
  }

return original value 
Log and return the original value.

Auto Deduplication

Even if you have multiple useTilg() hooks in the same component, the lifecycle events will only be logged once per component:

function MyApp() {
  const [input, setInput] = useState('')
  const [count, setCount] = useState(0)

  useTilg()
  useTilg()`input = ${input}`
  useTilg()`count = ${count}`

  return (
    <>
      <input onChange={(e) => setInput(e.target.value)} value={input} />
      <button onClick={() => setCount(count + 1)}>{count}</button>
    </>
  )
}

deduplication 
Render, mount, and unmount events will not be duplicated even if you have multiple useTilg() hooks.

CLI Support

If you are running your component during SSR, or running server-side tests, useTilg() properly outputs the result in Node.js CLI too:

function App() {
  const [count, setCount] = useState(42)
  
  useTilg()`The answer is ${{ answer: count }}`

  return <button onClick={() => setCount(count + 1)}>{count}</button>
}

deduplication 
Node.js CLI output.


 

FAQ & Caveats

Is it safe to ship code with useTilg to production?
Although useTilg() does nothing in a production build (process.env.NODE_ENV === 'production') but only an empty function, I encourge you to remove the hook from the source code after finishing the development of your app.

How do you implement this hook? What can I learn from the code?
It is very hacky. Don't do the same thing especially try it in production, or you will be fired.

Why not design the API as useTilg`message`?
Then it will not be identified as a hook, React Refresh and HMR will not work correctly.


Author: shuding
Source code: https://github.com/shuding/tilg
License: MIT license


#react-native  #typescript  #javascript 

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Tiny Logger: A Magical React Hook That Helps You Debug Components
Autumn  Blick

Autumn Blick

1598839687

How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

  • Performance: It delivers optimal performance.
  • Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
  • UI design: React Native enables you to design simple and responsive UI for your mobile app.
  • 3rd party plugins: This framework supports 3rd party plugins.
  • Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

  • Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
  • Near-native user experience: React Native provides several native components, and these are platform agnostic.
  • The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

What are hooks in React JS? - INFO AT ONE

In this article, you will learn what are hooks in React JS? and when to use react hooks? React JS is developed by Facebook in the year 2013. There are many students and the new developers who have confusion between react and hooks in react. Well, it is not different, react is a programming language and hooks is a function which is used in react programming language.
Read More:- https://infoatone.com/what-are-hooks-in-react-js/

#react #hooks in react #react hooks example #react js projects for beginners #what are hooks in react js? #when to use react hooks

Mark Mara

Mark Mara

1607399166

Class-less Components in React

While coding this week, I had to convert one of my class components in React to a functional component.

Why would I need to do that? After all, the parent component sees the two types of components as identical. Sure, functional components can be shorter, require less boilerplate, and maybe even perform better. But that’s not why I needed to do it. I was using an npm package that had React hooks and hooks are for functional components only. React Hooks, added in React 16.8, allow functional components to manage state and replace lifecycle methods. To use the hook I needed I had to convert my class components to a functional.

Here are the steps I followed to change my class component to a functional component:

#react-hook-useeffect #useeffect #react-hook #react-hook-usestate #react

Hayden Slater

1599277908

Validating React Forms With React-Hook-Form

Validating inputs is very often required. For example, when you want to make sure two passwords inputs are the same, an email input should in fact be an email or that the input is not too long. This is can be easily done using React Hook From. In this article, I will show you how.

Required Fields

The most simple, yet very common, validation is to make sure that an input component contains input from the user. React Hook Form basic concept is to register input tags to the form by passing register() to the tag’s ref attribute. As we can see here:

#react-native #react #react-hook-form #react-hook

The Ugly Side of React Hooks

In this post, I will share my own point of view about React Hooks, and as the title of this post implies, I am not a big fan.

Let’s break down the motivation for ditching classes in favor of hooks, as described in the official React’s docs.

Motivation #1: Classes are confusing

we’ve found that classes can be a large barrier to learning React. You have to understand how "this"_ works in JavaScript, which is very different from how it works in most languages. You have to remember to bind the event handlers. Without unstable syntax proposals, the code is very verbose […] The distinction between function and class components in React and when to use each one leads to disagreements even between experienced React developers._

Ok, I can agree that

thiscould be a bit confusing when you are just starting your way in Javascript, but arrow functions solve the confusion, and calling a_stage 3_feature that is already being supported out of the box by Typescript, an “unstable syntax proposal”, is just pure demagoguery. React team is referring to theclass fieldsyntax, a syntax that is already being vastly used and will probably soon be officially supported

class Foo extends React.Component {
  onPress = () => {
    console.log(this.props.someProp);
  }

  render() {
    return <Button onPress={this.onPress} />
  }
}

As you can see, by using a class field arrow function, you don’t need to bind anything in the constructor, and

this will always point to the correct context.

And if classes are confusing, what can we say about the new hooked functions? A hooked function is not a regular function, because it has state, it has a weird looking

this(aka_useRef_), and it can have multiple instances. But it is definitely not a class, it is something in between, and from now on I will refer to it as aFunclass. So, are those Funclasses going to be easier for human and machines? I am not sure about machines, but I really don’t think that Funclasses are conceptually easier to understand than classes. Classes are a well known and thought out concept, and every developer is familiar with the concept ofthis, even if in javascript it’s a bit different. Funclasses on the other hand, are a new concept, and a pretty weird one. They feel much more magical, and they rely too much on conventions instead of a strict syntax. You have to follow somestrict and weird rules, you need to be careful of where you put your code, and there are many pitfalls. Telling me to avoid putting a hook inside anifstatement, because the internal mechanism of hooks is based on call order, is just insane! I would expect something like this from a half baked POC library, not from a well known library like React. Be also prepared for some awful naming like useRef (a fancy name forthis),useEffect ,useMemo,useImperativeHandle(say whatt??) and more.

The syntax of classes was specifically invented in order to deal with the concept of multiple instances and the concept of an instance scope (the exact purpose of

this ). Funclasses are just a weird way of achieving the same goal, using the wrong puzzle pieces. Many people are confusing Funclasses with functional programming, but Funclasses are actually just classes in disguise. A class is a concept, not a syntax.

Oh, and about the last note:

The distinction between function and class components in React and when to use each one leads to disagreements even between experienced React developers

Until now, the distinction was pretty clear- if you needed a state or lifecycle methods, you used a class, otherwise it doesn’t really matter if you used a function or class. Personally, I liked the idea that when I stumbled upon a function component, I could immediately know that this is a “dumb component” without a state. Sadly, with the introduction of Funclasses, this is not the situation anymore.

#react #react-hooks #javascript #reactjs #react-native #react-hook #rethinking-programming #hackernoon-top-story