Full Stack React & Firebase Tutorial - Build and Launch Real-World App

Full Stack React & Firebase Tutorial - Build and Launch Real-World App

Full Stack React & Firebase Tutorial - Build and Launch Real-World Applications. Learn how to build and launch React & Firebase real time applications using React, Parcel, Babel, React-Router, & more!

React + Firebase: For Beginners

Full Stack React & Firebase Tutorial - Build and Launch Real-World Applications

Learn how to build and launch React & Firebase real time applications using React, Parcel, Babel, React-Router, & more!

Learn to build real-world applications using modern React! Much more than an intro, you’ll start from the ground up, getting all the way to using the latest features in React, including hooks, effects, context, and portals.

Throughout the course, you’ll piece together tools from the entire React ecosystem (like Reach Router) to build a full application.

Use the Firebase platform to deploy sophisticated web and mobile apps without having to build your own complex, server-side infrastructure. Get setup and learn to update React components in real time. Deploy your app, add OAuth authentication and activate database security rules.

What you'll learn

  • Learn to build real-world applications using modern React! Much more than an intro, you’ll start from the ground up, getting all the way to using the latest features in React, including hooks, effects, context, and portals.
  • Throughout the course, you’ll piece together tools from the entire React ecosystem (like Reach Router) to build a full application.
  • Use the Firebase platform to deploy sophisticated web and mobile apps without having to build your own complex, server-side infrastructure. Get setup and learn to update React components in real time. Deploy your app, add OAuth authentication and activate database security rules.

React Native Firebase - Firebase Integration in React Native - positronX.io

React Native Firebase - Firebase Integration in React Native - positronX.io

This is a step by step tutorial on learning how to integrate Firebase’s Firestore package in React Native application to access the full features of Real-time NoSQL database. Firebase is a well-known Backend-as-a-Service (Baas). It offers top-notch mobile application development experience to web developers. Firebase is Google’s mobile app development platform that empowers you to …

Understanding Fragments in React: What, Why and How

Understanding Fragments in React: What, Why and How

Understanding Fragments in React: What React Fragments are, how to use it and why it is a great feature. React Fragments is a feature that was introduced a while ago in React 16.2.0. React Fragments can be used whenever there are multiple elements, and they need to be wrapped in an enclosing tag. Fragments are invisible and do not get added on to the DOM. The DOM nodes are less cluttered with one less element, each time you add a fragment instead of a div. Fragments can take in keys as an attribute.

If you are a React developer, and haven’t heard of React Fragments yet, this post if for you. React Fragments is a feature that was introduced a while ago in React 16.2.0. But it is not as popular as it should be. In this post, we learn about what React Fragments are, how to use it and why it is a great feature. Let’s dive in right away.

What Are React Fragments ?

If you have been a React developer for a while, you would have probably run into a situation like this before:

import React from "react";

export default () => (
    <h1>Hello I am heading one </h1>
    <h1>Hey there I am another heading </h1>
);

This piece of React code will return the following error **_Parsing error: Adjacent JSX elements must be wrapped in an enclosing tag. _**I have encountered this error many times and I know that a React component with multiple elements need to be wrapped in something like a _

. _

The code then gets transformed into:

import React from "react";

export default () => (
    <div>
      <h1>Hello I am heading one </h1>
      <h1>Hey there I am another heading </h1>
    </div>
);

Adding a <div> to enclose the multiple elements gets rid of the error. This happens all across the code, whenever a component returns multiple elements, we end up enclosing it with a <div>.

This requirement by React results in a number of unwanted markupall across the DOM and is hard to debug. Sometimes it may even result in invalid HTML to be rendered.

Here is where React Fragments come in. The same piece of code can now be updated using a React Fragment, instead of the unnecessary

.

**React Fragments can group a list of children without adding extra nodes to the DOM. **This is a much need addition in React, because now you can just use React Fragments, which don’t render in the DOM, instead of using real elements like <div>.

import React from "react";

export default () => (
    <React.fragment>
      <h1>Hello I am heading one </h1>
      <h1>Hey there I am another heading </h1>
    </React.fragment>
); 

In the example above you can see that we don’t see the error anymore, and we are not rendering the additional

. Instead we are using fragments which are like invisible elements to wrap the components.

Example of Rendering Invalid HTML

Let’s look at a classic example, where adding

to enclose components with multiple elements can actually result in an invalid HTML. The best example for this would be using a Table Component below:

class TableComponent extends React.Component {
  render() {
    return (
      <table>
        <tr>
          <HeaderComponent />
        </tr>
        <tr>
          <td>Adhithi Ravichandran/td>
          <td>React Fragments</td>
          <td>100</td>
        </tr>
      </table>
    );
  }
}

In this example above, we have created a TableComponent that renders a table with a header and some content. Now the header for the table is another component called _HeaderComponent. _Let’s create a simple _HeaderComponent _for the table.

class HeaderComponent extends React.Component {
  render() {
    return (
        <th>Author Name</th>
        <th>Blog Post Title</th>
        <th>Likes</th>
    );
  }
}

// error: Adjacent JSX elements must be wrapped in an enclosing tag.

By the looks of it, the component looks right, I want it to return three header columns. But, React is going to throw an error “_Adjacent JSX elements must be wrapped in an enclosing tag.” _Well, now if went with the old approach of just adding a _

_around this component, it is going to return an invalid HTML.

Invalid HTML

class HeaderComponent extends React.Component {
  render() {
    return (
      <div>
        <th>Author Name</th>
        <th>Blog Post Title</th>
        <th>Likes</th>
     </div>
    );
  }

// error goes away, but this results in invalid HTML

In this case we have added

enclose the elements, but it will result in a random div in the middle of a table’s HTML. This is actually an invalid HTML. This is a perfect example to use the React Fragment instead.

Updated Code With Fragments

class HeaderComponent extends React.Component {
  render() {
    return (
      <React.Fragment>
        <th>Author Name</th>
        <th>Blog Post Title</th>
        <th>Likes</th>
      </React.Fragment>
    );
  }

With the above code, now our HeaderComponent just returns three table headers for each column, and the fragment is invisible and not a part of the DOM. This makes debugging the DOM easier, and removes any unnecessary clutter.

React Fragments Short Syntax

The fragments can also be used with a short syntax instead of calling out React.Fragments all the time. An empty tag and and empty closing tag can be used as a short syntax for fragments.

class HeaderComponent extends React.Component {
  render() {
    return (
      <>
        <th>Author Name</th>
        <th>Blog Post Title</th>
        <th>Likes</th>
      </>
    );
  }

**Note: **With the short syntax, you cannot assign a key or attribute to the element.

This brings up a point about keys. You can pass keys as an attribute to your fragment, when you don’t use the short syntax. This is useful when you have an array of fragments. And keys are currently the only attribute that can be passed to a fragment.

Conclusion

In this post, we learned about React Fragments.

  • React Fragments can be used whenever there are multiple elements, and they need to be wrapped in an enclosing tag.
  • This is an alternate to using
    when they are not necessary, just to get rid of the error thrown by React.
  • Fragments are invisible and do not get added on to the DOM.
  • The DOM nodes are less cluttered with one less element, each time you add a fragment instead of a div.
  • Fragments can take in keys as an attribute.

JavaScript Tutorial: if-else Statement in JavaScript

JavaScript Tutorial: if-else Statement in JavaScript

This JavaScript tutorial is a step by step guide on JavaScript If Else Statements. Learn how to use If Else in javascript and also JavaScript If Else Statements. if-else Statement in JavaScript. JavaScript's conditional statements: if; if-else; nested-if; if-else-if. These statements allow you to control the flow of your program's execution based upon conditions known only during run time.

Decision Making in programming is similar to decision making in real life. In programming also we face some situations where we want a certain block of code to be executed when some condition is fulfilled.
A programming language uses control statements to control the flow of execution of the program based on certain conditions. These are used to cause the flow of execution to advance and branch based on changes to the state of a program.

JavaScript’s conditional statements:

  • if
  • if-else
  • nested-if
  • if-else-if

These statements allow you to control the flow of your program’s execution based upon conditions known only during run time.

  • if: if statement is the most simple decision making statement. It is used to decide whether a certain statement or block of statements will be executed or not i.e if a certain condition is true then a block of statement is executed otherwise not.
    Syntax:
if(condition) 
{
   // Statements to execute if
   // condition is true
}

Here, condition after evaluation will be either true or false. if statement accepts boolean values – if the value is true then it will execute the block of statements under it.
If we do not provide the curly braces ‘{‘ and ‘}’ after if( condition ) then by default if statement will consider the immediate one statement to be inside its block. For example,

if(condition)
   statement1;
   statement2;

// Here if the condition is true, if block 
// will consider only statement1 to be inside 
// its block.

Flow chart:

Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate If statement 

var i = 10; 

if (i > 15) 
document.write("10 is less than 15"); 

// This statement will be executed 
// as if considers one statement by default 
document.write("I am Not in if"); 

< /script> 

Output:

I am Not in if
  • if-else: The if statement alone tells us that if a condition is true it will execute a block of statements and if the condition is false it won’t. But what if we want to do something else if the condition is false. Here comes the else statement. We can use the else statement with if statement to execute a block of code when the condition is false.
    Syntax:
if (condition)
{
    // Executes this block if
    // condition is true
}
else
{
    // Executes this block if
    // condition is false
}


Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate If-else statement 

var i = 10; 

if (i < 15) 
document.write("10 is less than 15"); 
else
document.write("I am Not in if"); 

< /script> 

Output:

i is smaller than 15
  • nested-if A nested if is an if statement that is the target of another if or else. Nested if statements means an if statement inside an if statement. Yes, JavaScript allows us to nest if statements within if statements. i.e, we can place an if statement inside another if statement.
    Syntax:
if (condition1) 
{
   // Executes when condition1 is true
   if (condition2) 
   {
      // Executes when condition2 is true
   }
}

Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate nested-if statement 

var i = 10; 

if (i == 10) { 

// First if statement 
if (i < 15) 
	document.write("i is smaller than 15"); 

// Nested - if statement 
// Will only be executed if statement above 
// it is true 
if (i < 12) 
	document.write("i is smaller than 12 too"); 
else
	document.write("i is greater than 15"); 
} 
< /script> 

Output:

i is smaller than 15
i is smaller than 12 too
  • if-else-if ladder Here, a user can decide among multiple options.The if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the ladder is bypassed. If none of the conditions is true, then the final else statement will be executed.
if (condition)
    statement;
else if (condition)
    statement;
.
.
else
    statement;


Example:

<script type = "text/javaScript"> 
// JavaScript program to illustrate nested-if statement 

var i = 20; 

if (i == 10) 
document.wrte("i is 10"); 
else if (i == 15) 
document.wrte("i is 15"); 
else if (i == 20) 
document.wrte("i is 20"); 
else
document.wrte("i is not present"); 
< /script> 

Output:

i is 20