Justen  Hintz

Justen Hintz

1556351611

Why React’s useContext() will clean your code?

#reactjs #javascript

What is GEEK

Buddha Community

Toby Rogers

1556352119

React’s useContext() API will save you lines of code and make your code easier to read. Best of all, it’s easy to implement. Let’s see how.

Quick Intro

I wanted to write a quick article to just explain how neat the useContext() hook can be utilized in React to clean up your code (there are many other uses to React Hooks but we will simply just look at useContext). I have seen that many developers are still a bit weary adopting some of these hooks (possibly because it only was released in the stable build of React this past February and some don’t see the need for it) [see the Official React Blog Post for more details]. The post is written by the great Dan Abramov who all of us React developers look up to, so give it a read when you get a chance. When you get curious for more info, visit the Official React Docs on Hooks that go in-depth on React Hooks and why they think they are so awesome (I think they are too).

The Before

I’m going to be making the assumption here that you have already been exposed to the React Context API and understand (at least on a surface level) how it works. Generally, utilizing Context in React allows us to pass data/information throughout the entire component tree without having to manually pass down props at every single level (i.e. passing down props to components that don’t need them). For those of you that are familiar with Redux or other state-management systems, you may already have a bit of knowledge in this area.

Let’s take a look at a component that utilizes the React Context API, but does not utilize useContext():

import React from "react";
import { UsernameContext } from "../../App.js";

const Header = props => {
  return (
    <IonHeader>
      <IonToolbar color="primary">
        <UsernameContext.Consumer>
          {({ username, changeUsername }) => (
            <IonTitle>
              {username === "" ? "Please login" : "You are logged in as "}
              {username}
            </IonTitle>
          )}
        </UsernameContext.Consumer>
      </IonToolbar>
    </IonHeader>
  );
};

As you can see in the example, I want my TitleBar of my App to be aware of the user’s username (which was provided by my top-level component). So in order to avoid passing down props through several components, I utilized the <Context.Consumer /> element that React gives us through the Context API. This all works, but we can make this all a bit cleaner with useContext().

As a quick note: If you are curious, the highest level component must also have a “Provider” that supplies all next Components with access to the context. It simply looks like this:

<UsernameContext.Provider value={this.state.user}>
  /*
  Any components that reside within the Provider
  will have access to the value of the context
  */
  <Header /> 
  /*...Other code here...*/
</UsernameContext.Provider>

If any of the above code looks foreign to you, please take a look at the React Context Official Docs. A Provider is still necessary for your React useContext Hook to work properly.

The After

After utilizing useContext() our code becomes less nested:

import React, { useContext } from "react";
import { UsernameContext } from "../../App.js";

const Header = props => {
  const userData = useContext(UsernameContext);
  return (
    <IonHeader>
      <IonToolbar color="primary">
        <IonTitle>
          {userData.username === "" ? "Please login" : "You are logged in as "}
          {userData.username}
        </IonTitle>
      </IonToolbar>
    </IonHeader>
  );
};

We were able to replace all of our **<UsernameContext.Consumer />**boilerplate with a simple call to useContext():

const userData = useContext(UsernameContext);

Then, just utilize **userData **wherever needed in your component. It’s as simple as that folks.

Closing Thoughts

I hope this clears up some of the confusion with React Hooks and why we now have an alternative way to access Context in React. Please remember, these features will always be backward compatible with the legacy React Context API and there are no plans by the React team to force developers to use React Hooks. They are just another tool on your belt, feel free to use it when *you *feel necessary.

Happy Coding!

Thanks for reading ❤

If you liked this post, share it with all of your programming buddies!

Follow me on Facebook | Twitter

*Originally published on *https://medium.com

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

Houston  Sipes

Houston Sipes

1604088000

How to Find the Stinky Parts of Your Code (Part II)

There are more code smells. Let’s keep changing the aromas. We see several symptoms and situations that make us doubt the quality of our development. Let’s look at some possible solutions.

Most of these smells are just hints of something that might be wrong. They are not rigid rules.

This is part II. Part I can be found here.

Code Smell 06 - Too Clever Programmer

The code is difficult to read, there are tricky with names without semantics. Sometimes using language’s accidental complexity.

_Image Source: NeONBRAND on _Unsplash

Problems

  • Readability
  • Maintainability
  • Code Quality
  • Premature Optimization

Solutions

  1. Refactor the code
  2. Use better names

Examples

  • Optimized loops

Exceptions

  • Optimized code for low-level operations.

Sample Code

Wrong

function primeFactors(n){
	  var f = [],  i = 0, d = 2;  

	  for (i = 0; n >= 2; ) {
	     if(n % d == 0){
	       f[i++]=(d); 
	       n /= d;
	    }
	    else{
	      d++;
	    }     
	  }
	  return f;
	}

Right

function primeFactors(numberToFactor){
	  var factors = [], 
	      divisor = 2,
	      remainder = numberToFactor;

	  while(remainder>=2){
	    if(remainder % divisor === 0){
	       factors.push(divisor); 
	       remainder = remainder/ divisor;
	    }
	    else{
	      divisor++;
	    }     
	  }
	  return factors;
	}

Detection

Automatic detection is possible in some languages. Watch some warnings related to complexity, bad names, post increment variables, etc.

#pixel-face #code-smells #clean-code #stinky-code-parts #refactor-legacy-code #refactoring #stinky-code #common-code-smells

Tyrique  Littel

Tyrique Littel

1604008800

Static Code Analysis: What It Is? How to Use It?

Static code analysis refers to the technique of approximating the runtime behavior of a program. In other words, it is the process of predicting the output of a program without actually executing it.

Lately, however, the term “Static Code Analysis” is more commonly used to refer to one of the applications of this technique rather than the technique itself — program comprehension — understanding the program and detecting issues in it (anything from syntax errors to type mismatches, performance hogs likely bugs, security loopholes, etc.). This is the usage we’d be referring to throughout this post.

“The refinement of techniques for the prompt discovery of error serves as well as any other as a hallmark of what we mean by science.”

  • J. Robert Oppenheimer

Outline

We cover a lot of ground in this post. The aim is to build an understanding of static code analysis and to equip you with the basic theory, and the right tools so that you can write analyzers on your own.

We start our journey with laying down the essential parts of the pipeline which a compiler follows to understand what a piece of code does. We learn where to tap points in this pipeline to plug in our analyzers and extract meaningful information. In the latter half, we get our feet wet, and write four such static analyzers, completely from scratch, in Python.

Note that although the ideas here are discussed in light of Python, static code analyzers across all programming languages are carved out along similar lines. We chose Python because of the availability of an easy to use ast module, and wide adoption of the language itself.

How does it all work?

Before a computer can finally “understand” and execute a piece of code, it goes through a series of complicated transformations:

static analysis workflow

As you can see in the diagram (go ahead, zoom it!), the static analyzers feed on the output of these stages. To be able to better understand the static analysis techniques, let’s look at each of these steps in some more detail:

Scanning

The first thing that a compiler does when trying to understand a piece of code is to break it down into smaller chunks, also known as tokens. Tokens are akin to what words are in a language.

A token might consist of either a single character, like (, or literals (like integers, strings, e.g., 7Bob, etc.), or reserved keywords of that language (e.g, def in Python). Characters which do not contribute towards the semantics of a program, like trailing whitespace, comments, etc. are often discarded by the scanner.

Python provides the tokenize module in its standard library to let you play around with tokens:

Python

1

import io

2

import tokenize

3

4

code = b"color = input('Enter your favourite color: ')"

5

6

for token in tokenize.tokenize(io.BytesIO(code).readline):

7

    print(token)

Python

1

TokenInfo(type=62 (ENCODING),  string='utf-8')

2

TokenInfo(type=1  (NAME),      string='color')

3

TokenInfo(type=54 (OP),        string='=')

4

TokenInfo(type=1  (NAME),      string='input')

5

TokenInfo(type=54 (OP),        string='(')

6

TokenInfo(type=3  (STRING),    string="'Enter your favourite color: '")

7

TokenInfo(type=54 (OP),        string=')')

8

TokenInfo(type=4  (NEWLINE),   string='')

9

TokenInfo(type=0  (ENDMARKER), string='')

(Note that for the sake of readability, I’ve omitted a few columns from the result above — metadata like starting index, ending index, a copy of the line on which a token occurs, etc.)

#code quality #code review #static analysis #static code analysis #code analysis #static analysis tools #code review tips #static code analyzer #static code analysis tool #static analyzer

Mathew Rini

1615544450

How to Select and Hire the Best React JS and React Native Developers?

Since March 2020 reached 556 million monthly downloads have increased, It shows that React JS has been steadily growing. React.js also provides a desirable amount of pliancy and efficiency for developing innovative solutions with interactive user interfaces. It’s no surprise that an increasing number of businesses are adopting this technology. How do you select and recruit React.js developers who will propel your project forward? How much does a React developer make? We’ll bring you here all the details you need.

What is React.js?

Facebook built and maintains React.js, an open-source JavaScript library for designing development tools. React.js is used to create single-page applications (SPAs) that can be used in conjunction with React Native to develop native cross-platform apps.

React vs React Native

  • React Native is a platform that uses a collection of mobile-specific components provided by the React kit, while React.js is a JavaScript-based library.
  • React.js and React Native have similar syntax and workflows, but their implementation is quite different.
  • React Native is designed to create native mobile apps that are distinct from those created in Objective-C or Java. React, on the other hand, can be used to develop web apps, hybrid and mobile & desktop applications.
  • React Native, in essence, takes the same conceptual UI cornerstones as standard iOS and Android apps and assembles them using React.js syntax to create a rich mobile experience.

What is the Average React Developer Salary?

In the United States, the average React developer salary is $94,205 a year, or $30-$48 per hour, This is one of the highest among JavaScript developers. The starting salary for junior React.js developers is $60,510 per year, rising to $112,480 for senior roles.

* React.js Developer Salary by Country

  • United States- $120,000
  • Canada - $110,000
  • United Kingdom - $71,820
  • The Netherlands $49,095
  • Spain - $35,423.00
  • France - $44,284
  • Ukraine - $28,990
  • India - $9,843
  • Sweden - $55,173
  • Singapore - $43,801

In context of software developer wage rates, the United States continues to lead. In high-tech cities like San Francisco and New York, average React developer salaries will hit $98K and $114per year, overall.

However, the need for React.js and React Native developer is outpacing local labour markets. As a result, many businesses have difficulty locating and recruiting them locally.

It’s no surprise that for US and European companies looking for professional and budget engineers, offshore regions like India are becoming especially interesting. This area has a large number of app development companies, a good rate with quality, and a good pool of React.js front-end developers.

As per Linkedin, the country’s IT industry employs over a million React specialists. Furthermore, for the same or less money than hiring a React.js programmer locally, you may recruit someone with much expertise and a broader technical stack.

How to Hire React.js Developers?

  • Conduct thorough candidate research, including portfolios and areas of expertise.
  • Before you sit down with your interviewing panel, do some homework.
  • Examine the final outcome and hire the ideal candidate.

Why is React.js Popular?

React is a very strong framework. React.js makes use of a powerful synchronization method known as Virtual DOM, which compares the current page architecture to the expected page architecture and updates the appropriate components as long as the user input.

React is scalable. it utilises a single language, For server-client side, and mobile platform.

React is steady.React.js is completely adaptable, which means it seldom, if ever, updates the user interface. This enables legacy projects to be updated to the most new edition of React.js without having to change the codebase or make a few small changes.

React is adaptable. It can be conveniently paired with various state administrators (e.g., Redux, Flux, Alt or Reflux) and can be used to implement a number of architectural patterns.

Is there a market for React.js programmers?
The need for React.js developers is rising at an unparalleled rate. React.js is currently used by over one million websites around the world. React is used by Fortune 400+ businesses and popular companies such as Facebook, Twitter, Glassdoor and Cloudflare.

Final thoughts:

As you’ve seen, locating and Hire React js Developer and Hire React Native developer is a difficult challenge. You will have less challenges selecting the correct fit for your projects if you identify growing offshore locations (e.g. India) and take into consideration the details above.

If you want to make this process easier, You can visit our website for more, or else to write a email, we’ll help you to finding top rated React.js and React Native developers easier and with strives to create this operation

#hire-react-js-developer #hire-react-native-developer #react #react-native #react-js #hire-react-js-programmer

Jackson George

1604649613

ECS: Residential & Commercial Cleaning Services in London

Specializing in commercial cleaning, office cleaning, hospital & GP surgery cleaning, residential cleaning, washroom cleaning, school cleaning, Covid cleaning and sanitization, ECS Commercial Cleaning Company London has built up a large, experienced team of highly-skilled team of professionals who ensures work is delivered to highest standards, on time and on budget.

At ECS Commercial Cleaning, we provide a safe, cost-effective and efficient service that covers all your commercial cleaning needs. From residential cleaning, washroom cleaning, school cleaning to office cleaning, hospital & GP surgery cleaning, we cater it all. We have years of experience with all kinds of projects and know the best approach to save you time and money. Our professional knowledge and skills has enabled us to provide high quality cleaning solutions throughout London.

We’ve been delivering commercial cleaning services throughout London with the help of trained and experienced professionals, using only the finest equipment and cleaning solutions. Our team starts cleaning project from initial consultation through to completion on budget and schedule.

ECS Commercial Cleaning strives to keep people first, investing in their professional training and safety. We work hard to create and sustain an environment that helps us to achieve clients’ expectations through consistently excellent service and minimal downtime.

Our Services

With 10 years of market experience, a resource of professional employees and coverage throughout the London, ECS Commercial Cleaning has established itself as one of the leading commercial cleaning company, offering valuable cleaning solutions including:

  • commercial cleaning
  • office cleaning
  • hospital & GP surgery cleaning
  • residential cleaning
  • washroom cleaning
  • school cleaning
  • covid cleaning and sanitization

Our clients are the London’s leading retail outlets, office buildings and office premises, schools, hospitals, production and industrial premises and others. Our cleaning solutions offers peace of mind to clients and most importantly ensure that workers are able to do their jobs comfortably and efficiently without compromising safety. Over the years of industry experience, we remain at the forefront of our industry due to our unparalleled customer dedication and unrivalled experience in providing safe, and cost-effective cleaning solutions.

Our Expert Team

ECS Commercial Cleaning provides you with an expert team that completes your cleaning project professionally and efficiently. No matter what cleaning service you require, our aim is to work closely with our clients in order to comprehend their needs and fulfil their specific requirements through tailored cleaning solutions.

With our eco-friendly cleaning products and a team of experienced professionals, we can provide timely cleaning solutions to our clients. Contact ECS Commercial Cleaning on 0161 5462235.

#cleaning #commercial cleaning #office cleaning #residential cleaning #washroom cleaning #covid cleaning and sanitization