Week 3: UI Frameworks

Introduction to Front-end Libraries

In the dynamic world of web development, front-end libraries play a crucial role in simplifying and streamlining the development process. These libraries provide pre-written code and components that can be easily integrated into web projects, saving developers time and effort while enhancing the functionality and appearance of web pages.

Benefits of Using Front-end Libraries

The adoption of front-end libraries offers several advantages, including:

1. Enhanced Productivity: Libraries provide ready-made code snippets and components, eliminating the need to reinvent the wheel. This significantly reduces development time and allows developers to focus on more complex tasks.
2. Code Reusability: Libraries promote code reusability, enabling developers to utilize the same code components across different projects. This consistency streamlines development and reduces the risk of errors.
3. Performance Optimization: Many libraries are designed with performance in mind, incorporating optimizations and best practices to ensure efficient rendering and interactions. This enhances the overall user experience.
4. Community Support: Popular libraries often have active communities of developers who contribute bug fixes, updates, and new features. This ensures long-term maintenance and support.
5. Standardization: Libraries promote standardization by providing consistent and well-documented code structures. This makes it easier for developers to collaborate and understand each other’s code.

Popular Front-end Libraries

The landscape of front-end libraries is vast and ever-evolving, with new libraries emerging regularly. Some of the most popular and widely used libraries include:

1. Bootstrap: A comprehensive CSS framework for building responsive and mobile-first web layouts.
2. jQuery: A popular JavaScript library for manipulating the DOM (Document Object Model) and handling events.
3. React: A JavaScript library for building user interfaces (UIs) based on reusable components.
4. Angular: A TypeScript-based framework for building single-page applications (SPAs).
5. Vue.js: A progressive JavaScript framework for building modern web applications.

Integrating Libraries into HTML

To incorporate front-end libraries into an HTML page, developers typically use two main methods:

1. CDNs (Content Delivery Networks): Libraries are hosted on CDNs, and their URLs are referenced in the HTML document. This ensures fast and reliable loading of the library files.
2. Local Installation: Libraries can be downloaded and installed locally within the project directory. This can be beneficial for offline development and customization.

Dependency Management

Managing dependencies, which are the external libraries and tools used in a project, can become complex as projects grow. To address this challenge, developers often utilize package managers like npm (Node Package Manager) or yarn. These tools automate the installation, updating, and removal of dependencies, ensuring compatibility and simplifying dependency management.

Bundling Tools

In larger projects, the number of dependencies can increase significantly, potentially affecting page loading times. To optimize performance, developers often employ bundling tools like Webpack or Parcel. These tools combine multiple files into a single file, reducing the number of HTTP requests and improving page loading speed.

Conclusion

Front-end libraries have become indispensable tools for web developers, providing a wealth of pre-built components, utilities, and best practices. By leveraging these libraries, developers can enhance the functionality, performance, and maintainability of their web projects. Understanding how to integrate and manage libraries effectively is essential for any front-end developer seeking to build modern and scalable web applications.

As a developer, deploying your application to a web server, you will use a bundling tool to:  (select the correct answer)

Combine all your dependencies into a single file.

That is correct! You will use a bundling tool to gather all your dependencies and combine them so that they can be referenced from your HTMLfile.

Hello and welcome. Imagine you want to cook a
dish you never tried before. You can try different
ingredients, different cooking times, or you can just use a recipe
found on the Internet. In a similar way as a developer, you can try to build your
website from scratch or you can use code that
other developers created. In this video, I’ll
illustrate how to include CSS and JavaScript libraries
in your HTML file. I’m also going to explain
what dependencies are, the purpose of a
package manager and JavaScript handlers.
Let’s get started. By now, you know you write code in your
application and that this code interacts with APIs provided by
libraries and frameworks. Since you’ll be deploying
your application to a web server in the end, you must include these libraries
and frameworks with it. If you do not include them, your application
won’t be able to call the API functions it needs
to execute when you run it. That is why the libraries and frameworks are often
referred to as dependencies. Your application
depends on them. On the front end, you
do this by referencing the JavaScript or CSS
files in your HTML file. One popular library
you can use to develop user interfaces is the
Bootstrap library. You will learn more about
Bootstrap in this course. But for now, let
me demonstrate how a library such as Bootstrap
can be included on a webpage. Start by opening your HTML file. Next, add the CSS library for Bootstrap in the head
element using a link tag. The link tag includes an H ref attribute to link the CSS
library I’m including. I also included a
rail attribute to specify that the link
is for a style sheet. Bootstrap also provides
a JavaScript library that enables enhanced
functionality, such as drop-downs and tooltips. You’ll likely need those
features during development. Let me demonstrate how to add the JavaScript library
to your webpage. Open your previous file that already has the Bootstrap CSS. Next, add the
JavaScript library for Bootstrap in the body element
using a script element. I then add an SRC attribute to the script element to specify
the link to the library. Let me add a Bootstrap
button to the page to demonstrate how easy
it is in the body, I add the button element. Then I add an attribute called type and the CSS class BTN. I also add the modifier btn dash primary,
and a description. Click this button. This will add a button using Bootstrap’s
primary color, blue on the webpage. This is what the
rendered version of the code will look like. You can now start using the additional Bootstrap
functionality. This is quite a simple example. In day to day
development, however, it can end up being a
lot more complicated. For example, what happens if your dependency also depends on other libraries
and frameworks? This is known as a
dependency tree. A project could have hundreds of dependencies and its tree, it will take a very
long time to download, setup, and configure
all of them. How do you make
sure you’re using the same versions the rest
of your team is using? This is where package
managers come in. A package manager is a tool that automatically downloads
and installs dependencies. We also refer to
dependencies as packages. A package manager also provides the capability to publish
your own packages. But let’s not worry
about that right now. For each dependency, you
can specify a version of that dependency and
the package manager will download it for you. If there is a dependency tree, the package manager takes
care of that for you. It will automatically
download all of the dependency tree
so that you can use APIs without
dependency issues. The most common package manager
for front end development is the Node Package
Manager or npm for sure. You will have an
opportunity to explore using NPM in this program. Now that all your
dependencies are downloaded, you need to include
them in your HTML file. But adding all of them into an HTML file would take forever. This is where you will
use a bundling tool. The purpose of a bundler is to automatically combine
them into a single file. If you’re bundle is
significantly large, many bundles can split your dependencies into
multiple bundles. There are many
bundle is available such as Gulp and Webpack. We’ll be exploring bundling
in more depth later on. You now know how to include CSS and JavaScript libraries
in your HTML file. You also know what
a dependency is, what the purpose of a
package manager is, and what JavaScript bundles are.

What is responsive design?

Responsive design is a set of web development techniques that make websites look good on all devices, regardless of the screen size or resolution. This is important because websites are increasingly being accessed from a variety of devices, including smartphones, tablets, laptops, and desktops.

With responsive design, the website automatically adjusts its layout to fit the device being used. For example, on a small smartphone screen, the website might display one column of content, while on a larger desktop screen, it might display three columns of content.

Why is responsive design important?

Responsive design is important for several reasons:

• Improved user experience: Responsive design ensures that websites are easy to use on all devices. This can lead to increased user satisfaction and engagement.
• Increased search engine optimization (SEO): Google and other search engines prefer websites that are responsive, as they provide a better user experience for mobile users.
• Reduced development costs: Responsive design can actually reduce development costs, as it eliminates the need to create separate websites for different devices.

How does responsive design work?

Responsive design is achieved through a combination of CSS techniques, including:

• Flexible grids: Flexible grids use percentages instead of pixels to define the width of columns, allowing them to adjust to different screen sizes.
• Fluid images: Fluid images are set to a maximum width of 100%, so they will scale down to fit in a smaller container but never grow larger than their original size.
• Media queries: Media queries allow developers to apply different CSS styles based on the device’s screen size, orientation, and other properties.

Getting started with responsive design

There are a number of resources available to help you get started with responsive design, including:

• Bootstrap: Bootstrap is a popular responsive design framework that provides a set of CSS and JavaScript tools for building mobile-first websites.
• W3Schools: W3Schools has a comprehensive tutorial on responsive design.
• Mozilla Developer Network (MDN): MDN has a number of articles on responsive design, including an introduction to responsive design and a guide to using media queries.

Responsive design is an essential skill for any web developer. By learning responsive design, you can ensure that your websites are accessible to all users, regardless of the device they are using.

There are media queries that are a part of the CSS version 3 specification. What do they allow developers to query in order to conditionally apply CSS rules? Choose all that apply.

Display Size, Orientation, Aspect Ratio

That’s correct! The media queries that are a part of the CSS version 3 specification that allows developers to query display size, orientation and aspect ratio.

Have you ever wondered how
the size of a website can so easily adjust between different devices
like laptops and mobile phones? Well, the answer is responsive design. Responsive design means that a web
page can automatically stretch or shrink depending on
the screen is displayed on. In the world of web development,
you use responsive design every day. Let me share how it works. In this video,you will be able to explain
how responsive design is used to provide the best user experience based on
the device that the website is viewed on. Describe CSS media queries and
screen resolutions, classified fluid images and differentiate
between fixed and fluid grids. Phone, tablet and computer screens
including the one you’re probably using now and made up of thousands
of tiny lights called pixels. The resolution of your screen refers to
the number of pixels it contains most often expressed as the number of
horizontal pixels multiplied by the number of vertical pixels. For example,
a common computer screen resolution is 1920 pixels in width
1080 pixels in height. Thanks to responsive design websites can
be correctly displayed on any of your devices. However, today we have many different
screens with different resolutions, which is why responsive design is so
important. And it is complicated by new high
resolution screens like the one found on your mobile phone. These screens group multiple physical
pixels into one logical pixel to display smoother images and text. These are often used in your favorite
smartphones to give more high definition visuals like making text images and
rounded edges appear smoother and making the individual pixels less visible. Given all the possibilities and
complicating factors, it would be challenging to develop
websites that appear correctly on all kinds of devices if it wasn’t for
responsive design. Responsive design is a set of three
practices that allows a website to automatically change its visuals. In other words, to respond based
on the device it is displayed on. It is the combination of three techniques,
flexible grids, fluid images and media queries. Firstly, flexible grids are made up
of columns, gutters and margins. The space between the columns is called
the gutter and the spaces between the content and the left and right
edges of the screen are called margins. Instead of defining website Element
sizes based on pixels, flexible grids are defined in percentage values, allowing
them to adjust depending on screen size. Next you have fluid images by setting the
CSS max width property of images to 100%. The images will scale down smaller
if they’re containing column becomes narrower than the images size but
never grow larger. This enables an image to scale down to
fit in a flexibly sized column rather than overflow it but not grow larger and become pixelated if the column
becomes wider than the image. Finally, there are media
queries that are part of CSS. They allow developers to query
the display size orientation and aspect ratio to conditionally
apply CSS rules. For example, if you wanted your website
background to appear blue on a screen size less than or equal to 700 pixels. Like on a mobile phone, you could use a
media rule to set the background depending on the size of the screen. Remember that I said responsive design
is the combination of flexible grids, fluid images and media queries. When these elements are used together, you
build a website that will automatically adjust its layout based on the device,
thus delivering a responsive grid. In responsive design, the pixel value specified is often
referred to as the breakpoint. A breakpoint is the point at
which a website’s content and layout will adapt to provide
the best possible user experience. A Breakpoint can function in different
ways across three different grids a fixed grid fluid or for
with grids and lastly, hybrid grids. Let’s explore each of these now, firstly, a fixed grid has fixed with columns and
flexible margins. The fixed grid has a fixed content
with that doesn’t change in a specific breakpoint range while the flexible
margins occupy the remaining space on screen. Then we have fluid or full width
grids with fluid with columns and fixed gutters and side margins. The fluid grid has a flexible content
with that goes edge to edge as per the screen size. In a fluid grid, columns either grow or
shrink to adapt to the available space. And finally there are hybrid grids
that have both fluid width and fixed with components. Many responsive design
frameworks provide multiple CSS rules based on different device sizes
to provide the best visual experience. Now you know the importance
of responsive design. In the next few videos, you’re going
to learn more about bootstrap, the world’s most Popular framework for
building responsive mobile 1st Sites.

Bootstrap: A Beginner’s Guide

Bootstrap is a widely used CSS framework that provides pre-styled components for building responsive and mobile-first websites. It simplifies the development process by eliminating the need to write repetitive CSS code and ensures consistent styling across different devices.

Prerequisites

Before you begin, ensure you have the following:

1. HTML and CSS: Familiarity with HTML and CSS is essential for understanding the structure and styling of Bootstrap components.
2. Code Editor: A code editor like Visual Studio Code or Sublime Text is necessary for writing and editing HTML, CSS, and JavaScript code.
3. Web Browser: A web browser like Chrome, Firefox, or Safari is required to preview your Bootstrap web pages.

Installing Bootstrap

Bootstrap can be downloaded and installed in two ways:

1. Download Bootstrap from Official Website: Visit the official Bootstrap website (https://getbootstrap.com/) and download the latest release of the Bootstrap package.
2. Use a CDN (Content Delivery Network): A CDN provides faster loading times and wider accessibility for your Bootstrap components. Use a CDN link in your HTML file to access Bootstrap’s CSS and JavaScript files.

Basic Structure of a Bootstrap Page

A basic Bootstrap page typically includes the following elements:

1. <!DOCTYPE html>: Declares the document type as HTML5.
2. <html>: Defines the root element of the HTML document.
3. <head>: Contains metadata and links to external resources like Bootstrap stylesheets.
4. <body>: Holds the visible content of the web page.
5. Bootstrap CSS: Include Bootstrap’s CSS file within the <head> section.
6. Bootstrap JavaScript: Include Bootstrap’s JavaScript file before the closing </body> tag.

Creating a Simple Bootstrap Page

1. HTML Structure: Create an HTML file and add the basic structure as mentioned above.
2. Bootstrap CSS: Link Bootstrap’s CSS file within the <head> section. Use a CDN link or a local link depending on your setup.
3. Bootstrap Grid System: Utilize Bootstrap’s grid system to create a layout for your web page. Divide the page into rows and columns using Bootstrap’s grid classes.
4. Bootstrap Components: Insert Bootstrap components like buttons, dropdown menus, navbars, and forms to enhance the user interface and interactivity.
5. Styling with Custom CSS: Modify Bootstrap’s default styles using your own custom CSS rules to achieve the desired look and feel for your web page.

Resources and Further Learning

1. Official Bootstrap Documentation: The official Bootstrap documentation provides comprehensive guides, tutorials, and API references.
2. Bootstrap Examples: Explore Bootstrap’s extensive collection of examples to see how different components can be used together.
3. Online Courses and Tutorials: Numerous online courses and tutorials offer step-by-step guidance on building Bootstrap websites.
4. Bootstrap Community: Engage with the Bootstrap community through forums, discussions, and social media groups to seek help and share knowledge.

Bootstrap is a powerful tool for creating responsive and modern web pages. By following these steps and utilizing available resources, you can effectively implement Bootstrap to build your web applications.

Part of designing a
website is thinking about how different UI
elements and menus are positioned on the page and
in relation to each other. Bootstrap is a collection of pre-written code chunks in CSS
and JavaScript that allows you to create websites
more quickly than if you had to create every bit
of code from scratch. Building websites
from scratch every time will be quite
time-consuming. This is where
Bootstrap comes in. In this video, you
will learn how to create a simple
Bootstrap webpage. To do that, I am
using the file with the Bootstrap libraries
I have created. Let’s begin by setting
up the layout. The first element I need
to add when setting up a Bootstrap website is
the container elements. I need it before I can use
the Bootstrap grid system. I add HTML div element and apply the container CSS
class provided by Bootstrap. Next, I add a row
for the contents. Similar to what I had in
the container elements, a row is a HTML div element, which uses the row CSS class
provided by Bootstrap. Under this row, I want
to add two columns, one for the menu items
and one for the prices. I add two div elements
with the col CSS class, one for each column. Col is short for column. Now I want to name the columns. I do this by adding
heading tags in each div. Within the first column div, I add a heading 1 tag or H1 tag. I type the name of
the column, our menu. The second column div element
I type prices in a H2 tag. Under the our menu column, I will add the
name of each dish, the ingredients
used, and an image. First, I add a heading 2 tag
below the our menu H1 tag, and inside it, I add the
name of the dish, falafel. On the falafel H2 tag, I add a paragraph tag or p tag. Inside this tag, I
list the ingredients, chickpea, herbs, and spices. Now to add an image
of a falafel, I add the IMG or image
tag and inside it add the SRC or source
attribute as it is known. In the source attribute, I enter the name of the image
file I want to link to. I type falafel.jpeg. I now add a CSS class called
IMG-fluid or image fluid, as most developers call it. Instead of having to
manually set the image size, the IMG-fluid class will ensure my image scales to its
parent column’s width. Next, let’s add another dish. I add another
heading 2 or H2 tag, and inside it, I add the name
of the dish pasta salad. Under the pasta salad H2 tag, I add a paragraph tag or p tag, and list the ingredients, lettuce, vegetables,
and mozzarella. Now I add another image tag and inside it add the
source attribute. In the source attribute,
I enter the name of the image file
I want to link to. I type salad.jpeg. I also add the same
CSS class image-fluid. Now I save the file by pressing
the keys Control and S, or if you’re on a Mac
Command and S. Next, I preview the webpage
in live preview. The dishes are now
displayed in columns and the images are
sized correctly. Now let’s add the price table. Under the price column, I add a HTML table tag and apply the
Bootstrap CSS class table. Inside the HTML table tag, I add two table row
tags or tr tags. This will create a row
for each of the dishes. Then I need to add table
data tags or td tags. The table data tags to find
the contents of table cells. I’ll need to add two of
those inside each table row, one for the dish name
and one for its price. In the first row, I add
falafel to the first td tag, and in the second td tag, I add the price, let’s say $12. I do the same with
the second row. I type pasta salad inside the first td tag and the price of $10 in
the second td tag. I save the file again
by pressing Control and S or if you’re on Mac
Command and S. Next, I preview the webpage
in live preview. The table structure now displays using Bootstrap’s table style. You’ve now learned how to make a simple webpage
using Bootstrap.

Introduction to Bootstrap Styles

Bootstrap is a popular CSS framework that provides a collection of pre-designed styles for creating responsive and mobile-first websites. It simplifies the development process and ensures consistent styling across different devices and browsers. Bootstrap offers a wide range of styles for various components, including buttons, forms, tables, navigation bars, modals, and more.

Getting Started with Bootstrap

To use Bootstrap styles, you can download the Bootstrap CSS and JavaScript files from the official website (https://blog.templatetoaster.com/how-to-create-bootstrap-website/) and include them in your HTML page. You can also use a CDN (Content Delivery Network) to link to the Bootstrap files, which can improve loading times and accessibility.

Bootstrap Grid System

The Bootstrap grid system is a fundamental component for creating responsive layouts. It divides the webpage into rows and columns, allowing you to arrange content in a flexible and organized manner. The grid system uses a set of CSS classes that define the width and alignment of columns based on different screen sizes.

Bootstrap Components

Bootstrap provides a variety of pre-built components that you can easily integrate into your web pages. These components include buttons, forms, tables, navigation bars, modals, and more. Each component has its own set of CSS classes and JavaScript code for styling and functionality.

Customizing Bootstrap Styles

While Bootstrap provides a comprehensive set of styles, you can also customize the default styles to match your specific design preferences. You can override Bootstrap’s CSS rules using your own custom CSS rules, allowing you to tailor the appearance of your website.

Resources and Further Learning

The official Bootstrap documentation (https://getbootstrap.com/docs/4.1/getting-started/introduction/) is an excellent resource for learning about Bootstrap styles, components, and customization options. There are also numerous online courses, tutorials, and examples available to help you get started with Bootstrap.

Tutorial: Creating a Simple Bootstrap Webpage

Here’s a simple example of creating a webpage using Bootstrap styles:

HTML

<!DOCTYPE <strong>html</strong>>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Bootstrap Example</title>
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/css/bootstrap.min.css" integrity="sha384-rbsA0YxHBNaU+30Mp+x2Q4/4j8tEX8w+O/O5k2Q2o05t32oL0+T2sK8lQ9zd" crossorigin="anonymous">
</head>
<body>
  <div class="container">
    <h1>Bootstrap Example</h1>
    <p>This is a simple paragraph using Bootstrap's default paragraph styling.</p>
    <button type="button" class="btn btn-primary">Click Me</button>
  </div>

  <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-kenU1KFdBIe4zVF0s0G1M5b4hcpxyD9F7jL+jjXkk+Q2h455rYXK/JVxBRHvxZ" crossorigin="anonymous"></script>
</body>
</html>

This example includes the basic Bootstrap CSS and JavaScript files, a container element to organize the content, and a button component styled with Bootstrap’s primary button style.

As you explore Bootstrap further, you’ll discover its vast collection of styles, components, and customization options to create responsive, attractive, and functional web pages.

Yes or no!

As a web developer, you will use a modifier to indicate the breakpoint in Bootstrap CSS rules.

No

That’s right! Bootstrap modifiers add a CSS class to change the visual style of components. You will use an infix to indicate the breakpoint in Bootstrap CSS rules.

As a developer, you were tasked to design
a website for the Little Lemon Restaurant. One of the main requirements is that
the website easily adapts to different devices, platforms and screen sizes. Does this mean that you have to
redesign the website for each device? No, relax. You do not have to redesign
your website for each device. In this video, I’ll introduce you
to Bootstrap CSS class in fixes and modifiers. And you will learn how you can
use them to save your time. Let’s get started. Bootstrap has quite a large CSS library
built by Bootstraps developers using thousands of use cases. How it achieves this is
through CSS classes and their variations through in fixes and
modifiers. It is important that you as a developer,
understand in fixes and modifiers and you will explore each of these terms. You will use class in fixes for responsive
breakpoints in the Bootstrap grid system, let’s go ahead and
cover how in fixes are used. You already know that breakpoints
are the triggers in bootstrap for how your layout changes across device or
viewpoint sizes. Here are the responsive breakpoints
available in bootstrap and how we use them. Know that each has a specific name. Extra small is for
screens less than 576 pixels wide. Small is for screens greater than or
equal to 576 pixels wide. In bootstrap CSS rules,
this is abbreviated as SM. Medium is for screens greater than or
equal to 768 pixels wide. In Bootstrap CSS rules,
this is abbreviated as MD. Large is for screens greater than or
equal to 992 pixels wide. In Bootstrap CSS rules,
this is abbreviated as LG. Extra large is for screens greater than or
equal to 1200 pixels wide. In bootstrap CSS rules
this is abbreviated as XL. Extra extra large is the screen is greater
than or equal to 1400 pixels wide. In bootstrap CSS rules,
this is abbreviated as XXL. Did you notice that there is no
class in fix or dimension for extra small on the list? This is because extra small is the default
breakpoint in Bootstrap CSS rules. As bootstrap is mobile first. We use the abbreviations for these breakpoints as in fixes in
the CSS rules for the grid system. This basically means you have to insert
the abbreviation into the CSS class name. I will show you how to use this shortly. Bootstrap components provide a pre built
set of reusable UI styles and elements for your web applications. Let’s now learn how to use modifiers
through an example that uses an alert element. I can have an html file where I set an
alert primary CSS class that is applied to the element. Alert primary displays the alert using
Bootstraps primary color which is blue. The dash primary part of
the class is the modifier. If you want to change this to red for
example, for an error message you will
use the danger modifier. Here is a list of modifiers
available in Bootstrap. Primary, secondary, success, info,
warning, danger, light, dark. Alerts are often used to show information
that needs immediate attention from users such as warnings, errors or
confirmation messages. Bootstrap provides an easy way to
create predefined alert messages and it also has different types of alerts. The difference between the alerts is just
the color used to display the predefined alert message. For example, the primary alert displays the alert using
bootstraps primary color which is blue. On the other hand, the danger
alert displays the alert in red. Now, let’s turn our attention
to how this works in code. In this html file, I have a six columns
CSS class applied to a div element. In this example, I want to change
this rule for large screens. To do this, I in fix LG into the col CSS
class, by adding col dash LG dash six. Bootstrap components provide a pre built
set of reusable UI styles and elements for your web applications. For example, I can add an alert component. I do this by adding an alert CSS class
followed by the contextual class, alert dash primary. Now I have to identify
the function of the alert. To do this, I add a roll CSS class
directly after the contextual class, alert dash primary and type alert. On the next line, I type the name
that must be displayed on the alert. A message. Alerts are useful for
displaying information, warnings or error messages to users. The contextual class, alert primary will display the alert using
Bootstraps primary color, which is blue. The primary part of
the class is the modifier. If I want to change the color to red,
for example, for an error message, I will use the danger modifier. To change the color to red, I simply
replace the modifier Primary with danger. Now you have learned about CSS
class in fixes and modifiers and how you can use them to save you time.

Introduction

Bootstrap is a popular front-end framework that includes a comprehensive grid system. The grid system helps developers create responsive layouts that adapt to different screen sizes. Bootstrap’s grid system is based on a 12-column system, and it includes a variety of classes that can be used to create different layouts.

Basic Structure

The basic structure of the Bootstrap grid system consists of three main components:

• Container: The container is the outermost element of the grid. It defines the width of the grid and applies padding to the content.
• Row: A row is a horizontal group of columns.
• Column: A column is a vertical section of a row.

Creating a Layout

To create a layout with the Bootstrap grid system, you first need to create a container element. Inside the container, you can create one or more row elements. Inside each row, you can create one or more column elements.

Column Sizes

Bootstrap columns are sized using a series of classes. The most common column sizes are col-xs-1 to col-xs-12, col-sm-1 to col-sm-12, col-md-1 to col-md-12, col-lg-1 to col-lg-12, and col-xl-1 to col-xl-12. These classes correspond to different screen sizes:

• col-xs-*: Extra small (phones)
• col-sm-*: Small (tablets)
• col-md-*: Medium (desktops)
• col-lg-*: Large (desktops)
• col-xl-*: Extra large (large desktops)

Responsive Layouts

Bootstrap’s grid system is responsive, which means that the columns will automatically resize to fit the screen size. For example, if you have two columns on a desktop screen, they will collapse into one column on a mobile screen.

Offsets

Bootstrap’s grid system also includes offset classes that can be used to offset columns. For example, the col-md-offset-6 class will offset a column by six columns on medium devices.

Gutters

Bootstrap’s grid system includes gutters, which are the spaces between columns. Gutters make it easier to read content and make layouts look more polished.

Example

Here is an example of how to create a two-column layout with Bootstrap:

HTML

<div class="container">
  <div class="row">
    <div class="col-md-6">
      <h2>Column 1</h2>
      <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
    </div>
    <div class="col-md-6">
      <h2>Column 2</h2>
      <p>Nulla facilisi. Nullam ac quam non erat bibendum semper.</p>
    </div>
  </div>
</div>

This code will create two columns that are each six columns wide on medium devices (tablets and desktops). The columns will be offset by six columns on small devices (phones).

Conclusion

Bootstrap’s grid system is a powerful tool that can be used to create responsive layouts. It is easy to use and well documented, and it is a popular choice for web developers.

Bootstrap's Grid System is structured with 3 types of elements. Select the correct types from the following options:

Containers, Rows, Columns

Correct! The Bootstrap’s Grid system always contains container rows and columns.

As you have previously learned building
a website using responsive design requires a responsive grid and
responsive breakpoints. Bootstrap provides both of
these as part of its library. The bootstrap grid system helps us to
create web page layouts through a series of rows and
columns that house our content. For the grid, bootstrap uses a 12 column
grid system that can be fluid or fixed. The bootstrap grid system always
has a container, rows and columns. The container is the root
element of your grid. Bootstraps grid system always
starts with the container. The container contains pads and
aligns your content. Its width is determined based on
the current responsive breakpoint. You can add rows and
inside each row you can add columns. Let me demonstrate how we put
this all together by using little lemons website as an example. All right, I have opened my
joe’s burger index.html file. In this web page I have
added two columns to my row. Bootstrap is smart and will set the two
columns to span six columns spaces. If I want to control how many spaces
a column uses, I can suffix a number. Let’s shrink the price
column to four spaces and expand the menu column to eight spaces. To do this, I add the suffix-4 to the coal
CSS class above the prices heading. I also add the suffix-8 to the coal
CSS class above our menu heading. But here’s the amazing part of bootstrap. I can configure my content to use
different layouts based on the device using the breakpoint specific CSS rules. Let’s have the content stacked on top
of each other on mobile devices and have them display side by
side on desktop devices. Since columns will wrapped in euros,
if we exceed the 12 column space, we can use this to stack content. For mobile devices, I’ll set the columns
to use 12 spaces each by adding 12 as a suffix to the coal rule for
both columns. Then for desktop I’ll set them to six
columns each by using a cold- LG rule and adding the column sizes-6 as a suffix. I will save the file by
pressing control and s or command s on a Mac and
open it on my web browser. Notice that now the columns
are side by side. Next I opened my web developer
tools by pressing the F- 12 key. In the top left corner,
there is a mobile phone tablet button. Clicking on this button
enables the device mode. This allows me to simulate
different devices. I select to view my website on
a mobile phone device, amazing. My content has stacked
vertically on mobile. Bootstrap has ensured our website will
work on a mobile phone thanks to its CSS rules and grid system. This will save a lot of development
time by not needing to develop different content layouts per device. Bootstraps grid system is very powerful
and suitable for most development needs

Bootstrap Components

Bootstrap components are pre-built UI elements and styles that help you quickly and easily create responsive and visually appealing websites. These components include buttons, forms, navigation menus, tables, and more.

Benefits of Using Bootstrap Components

There are several benefits to using Bootstrap components, including:

• Faster development: Bootstrap components can save you a lot of time and effort by providing pre-built HTML, CSS, and JavaScript code.
• Responsive design: Bootstrap components are designed to be responsive, meaning they will adapt to different screen sizes and devices.
• Consistent design: Bootstrap components have a consistent look and feel, which can help to make your website look more professional.

Getting Started with Bootstrap Components

To get started with Bootstrap components, you first need to download and include the Bootstrap CSS and JavaScript files on your website. You can do this by downloading the Bootstrap files from the GetBootstrap website or by using a CDN (content delivery network) such as jsDelivr.

Once you have included the Bootstrap files on your website, you can start using the components by adding the appropriate CSS classes to your HTML elements. For example, to create a button, you would add the btn CSS class to a button element.

Examples of Bootstrap Components

Here are a few examples of Bootstrap components:

• Buttons: Buttons are used to trigger actions on a website. Bootstrap has a variety of button styles, including primary, secondary, and success buttons.
• Forms: Forms are used to collect data from users. Bootstrap has a variety of form elements, such as input fields, select boxes, and checkboxes.
• Navigation menus: Navigation menus are used to help users navigate a website. Bootstrap has a variety of navigation menu styles, including horizontal and vertical menus.
• Tables: Tables are used to display tabular data. Bootstrap has a variety of table styles, including striped and bordered tables.

Additional Resources

There are a number of resources available to help you learn more about Bootstrap components, including:

• The Bootstrap documentation: https://getbootstrap.com/
• The Bootstrap tutorial: https://m.youtube.com/watch?v=O_9u1P5YjVc
• The Bootstrap components example page: https://getbootstrap.com/docs/5.0/customize/components/

I hope this tutorial has been helpful. Please let me know if you have any questions.

If I want to notify clients that Little Lemon has added a new burger to their menu. To do this I will use a Bootstrap Component. Which CSS classes can I use? Select all that apply.

alert-info, alert

Boot trap includes a pre
made set of UI elements and styles to help you build your website. They range from alert
messages to navigation menus. These are called bootstrap components. In this video you will learn how
to use bootstrap components. Little lemon have added a new fried
calamari dish to the menu and they want to add it to their website. They also want to update the website
to use bootstrap components. First, let’s add the new dish. To do this in the menu column,
I add a new h2 tag and inside it I add the name
of the dish Fried Calamari. I didn’t add a paragraph
tag inside this tag, I list the ingredients,
squid and buttermilk. Now I want to add an image
of the fried calamari. So I used an image tag with
its source attribute and the image file name calamari.jpeg. And I add the image dash fluids CSS class to ensure that the image scales
to its parent columns width. Bootstrap comes with a badge component
that I can use to highlight that the dish is new. Let’s add that now. Next to Fried Calamari,
Inside the h2 element, I add a span element and
assign it a CSS class of badge. Now I can set the background
color of my badge by adding another class called bg-primary. The contextual class bg-primary
will display the badge using bootstraps primary
color which is blue. Inside the span I added text new. Next I’m going to improve the visuals by
using the card component for each dish. With card elements I can style and
accommodate different types of contents like title’s subtitle body copy and
images for the cards. Let’s have them stack on mobile devices
and tile side by side on desktop. To do this, I add a row below the our menu h1 tag. I then add a div element for each dish of the three dishes. For each day of I applied
a col-12 class for mobile devices and a col-Lg-6 class for desktop devices. Inside each div of elements, I added narrative elements that uses the card CSS class by adding one and copying and pasting it inside other dudes. Then move the code with the image tag of each dish to the card class. Instead of using img-fluid I change
each image to card- img-top. This will improve its visual
style within the card. I then add another day for each dish and
give it the card-body css class. This will contain the text
content of the card. I then moved the header and paragraph of
each dish into these card body elements. Again, to improve the visual style, I add a card-title css class to the header of each dish. In the paragraph elements I add a car- text css class for each description. Let’s preview in live preview. Our menu has a much better layout now. Finally let’s update the prices Under the price column
I add a table row or tr tags for the new dish. I then add 2 td tags but
from now on I will just refer to it as td. In the first row, I typed fried calamari,
in the first td tag and in the second td tag,
I typed the price of $12. Now I will add an alert to inform
our customers about the new dish so that they can try it out. To do this I add a div element
with the alert css class. I then add the alert-info css
class to change the alert to blue. Now identify the function
of the alert by adding a role attribute directly after
the contextual css class. For its value I type alert. On the next line. I typed text that must be
displayed on the alert. Try our new fried calamari. Let’s see how it looks in live preview. The website has a much better layout now, hopefully little lemon will
have a lot more orders now. There are many components
available in Bootstrap. Maybe there are some more you
can use to improve your website

Static vs. Dynamic Content in React: Building Flexible and Engaging UIs

React shines in building dynamic and interactive user interfaces. But sometimes, static content is just what you need. Let’s explore the differences between static and dynamic content in React and how to use each effectively.

Static Content:

• What is it? Text, images, and other elements that don’t change based on user interaction or data. Think headings, logos, and basic page layouts.
• How to create it? Use plain HTML, JSX syntax, or components that return fixed content.
• Benefits: Simple, fast, and easy to maintain. Perfect for foundational UI elements.

Dynamic Content:

• What is it? Content that updates based on user actions, data fetching, or state changes. Think user-generated comments, real-time charts, and personalized recommendations.
• How to create it? Use state management libraries like Redux or Context API to store and update data, then render components based on that data.
• Benefits: Creates engaging and responsive UIs, personalizes the user experience, and reacts to changing data.

Choosing the Right Approach:

• Use static content for:
  • Basic layout elements (header, footer, navigation)
  • Logos, icons, and other branding elements
  • Simple text or image displays
• Use dynamic content for:
  • User input forms and feedback displays
  • Data visualizations and charts
  • Content that personalizes based on user data
  • Live chat features and other real-time updates

Remember:

• Static and dynamic content are not mutually exclusive. You can combine them to build rich and interactive UIs.
• Static content forms the foundation, while dynamic content adds the interactivity and personalization.

Tips for Working with Dynamic Content:

• Keep state changes minimal: Only update the necessary parts of the UI to avoid unnecessary re-renders.
• Use efficient data fetching: Consider techniques like memoization and lazy loading to optimize performance.
• Provide clear feedback: Let users know when content is loading or updating.

Examples:

• A product page with static product information (description, image) and dynamic user reviews.
• A social media feed with static post layout and dynamic user content (text, images, comments).
• A dashboard with static charts and dynamic data updates based on real-time metrics.

By understanding static and dynamic content and using them strategically, you can build React applications that are both visually appealing and engaging for your users.

Feel free to ask if you have any questions about specific scenarios or want to explore more advanced techniques!

I’m sure you’ve noticed
that when you shop online, websites will often provide you with personalized
recommendations. But when your friends login
to those same websites, the recommendations will differ. But did you ever
wonder how websites adapt to different
user profiles? In this video, you’ll learn the difference between
static and dynamic content. You will also be able to
differentiate between the role of a web server
and an application server. By now, you know that
when you open a website, a web server sends the website’s
content to your browser. The content can be
static or dynamic. Static content is files that the server transfers just as they are stored
on the web server, such as videos or images. Dynamic content,
on the other hand, is generated when the
HTTP request is made. For example, the content may be generated based on
input from a user, or when you visit
a news website, it would be based on
the current date. What actually happens, is that the web server communicates with
another kind of server, called an application
server or a back-end. The application server generates the dynamic content that the web server sends back
to the user’s browser. Now you know the difference. Let’s look at examples
of how websites update static and
dynamic content. Say for instance, you want to
watch a video on a website, you click on the Play button and a request is sent
to the web server. The web server responds by sending the file
to your browser. Now, how does this compare
to dynamic content? Because dynamic content is generated while
you use a website, it typically takes
longer to generate than it takes to send
back static content. For example, when you
log into this course, the web server communicates with an application server to check that you are in fact enrolled. The application server
confirms your enrollment and specifies what content should show for your profile
specifically. Application servers perform more complex processing
than web servers. For instance, they have to
run the application logic, communicate with the database,
and check permissions. To improve performance, different application servers
have specific purposes. There are application
servers for every type of content out there, from music streaming to
creating your own blog. You can even create your
own application servers, such as building a back-end
for a web application. But hang on, If dynamic
content is slower to generate, isn’t that a problem for
big websites? Yes, it is. Application servers
typically have a limited capacity on how many requests they
can process per second. But fortunately, this is where the web server
can help out. Web servers use a
process called caching instead of generating content dynamically for every request. Caching means the web server keeps a copy of dynamic content. If the content is
requested again, the web server can
immediately send this cached version
instead of passing the request again to
the application server. On the first request
for dynamic content, the web server checks if the
content exists in the cache. If it does not exist, the content is requested from the application server
and stored in the cache. The web server then sends back the dynamic content
to the browser. On subsequent requests,
the web server immediately sends back the
content stored in the cache. This reduces the amount of dynamic content that the application server
has to generate. Then, after a period of time or with the next
user interaction, the web server updates the
cache with the latest content. Now you know the
difference between static and dynamic content, as well as the
difference between web and application servers. With this new information, try to identify
with the content on the websites you visit
is static or dynamic.

Single page applications (SPAs) offer dynamic and engaging user experiences through efficient page transitions and data manipulation. React, a popular JavaScript library, is well-suited for building SPAs due to its component-based architecture and virtual DOM. This tutorial will guide you through the fundamentals of creating single-page applications in React.

Prerequisites:

• Basic understanding of HTML, CSS, and JavaScript
• Familiarity with React fundamentals (including components, props, and state)

Setting Up the Environment:

1. Install React and React DOM:

Bash

npm install react react-dom

2. Create a React project:

Bash

npx create-react-app my-spa

3. Navigate to the project directory:

Bash

cd my-spa

4. Start the development server:

Bash

npm start

This will open your application in a web browser at http://localhost:3000.

Building Your First SPA:

1. Create a basic React component:

JavaScript

// src/App.js

import React from 'react';

function App() {
  return (
    <div>
      <h1>Hello, World!</h1>
    </div>
  );
}

export default App;

This component renders an “Hello, World!” message.

2. Update the App component to display dynamic content:

JavaScript

// src/App.js

import React, { useState } from 'react';

function App() {
  const [message, setMessage] = useState('Hello, World!');

  const handleClick = () => setMessage('Welcome to your SPA!');

  return (
    <div>
      <h1>{message}</h1>
      <button onClick={handleClick}>Click Me!</button>
    </div>
  );
}

export default App;

This component defines a state variable message and a function handleClick to update it. Clicking the button changes the displayed message.

3. Adding Routing:

To navigate between different pages in your SPA, you can use a routing library like React Router.

Bash

npm install react-router-dom

4. Create separate components for different pages:

JavaScript

// src/components/Home.js

import React from 'react';

function Home() {
  return (
    <div>
      <h1>Welcome Home!</h1>
    </div>
  );
}

export default Home;

JavaScript

// src/components/About.js

import React from 'react';

function About() {
  return (
    <div>
      <h1>About Us</h1>
      <p>This is a single-page application built with React.</p>
    </div>
  );
}

export default About;

5. Configure routes in the main App component:

JavaScript

// src/App.js

import React from 'react';
import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';
import Home from './components/Home';
import About from './components/About';

function App() {
  return (
    <Router>
      <Switch>
        <Route exact path="/" component={Home} />
        <Route path="/about" component={About} />
      </Switch>
    </Router>
  );
}

export default App;

This code defines routes for the home and about pages.

Next Steps:

This tutorial provides a basic understanding of SPAs in React. To further enhance your SPA, consider:

• Implementing state management libraries like Redux
• Fetching data from APIs using libraries like Axios
• Adding user authentication and authorization
• Utilizing advanced routing features like dynamic routing and protected routes
• Implementing styling libraries like Material UI or Bootstrap
• Testing your SPA with libraries like Jest and Cypress

Remember, building SPAs involves continuous learning and exploration. Keep practicing and experimenting to build dynamic and engaging user experiences.

Which of the following are SPA approaches to serving code? Select all that apply.

Bundling, Lazy loading

Yes, bundling will return all resources immediately and lazy loading returns only the minimum required resources.

Let’s say that you’re thinking
of building a web app. You probably want
a user-friendly, mobile-friendly experience. Then you should consider using single-page applications
or SPAs to build a unique, speedy, and engaging
experience for your users. You’re probably using
many SPAs every day. Think of your favorite
social network or messaging app or
the map application you use to find
local businesses. The great user
experience you get is driven by single-page
applications. So, what exactly is an
SPA? How does it work? How is it different from
a traditional website? Let’s first explore how
traditional website works. Before the advent of modern
JavaScript frameworks, most websites were implemented as multi-page applications. But this makes traditional applications resource
intensive to web servers because sending
entire web pages for every request consumes excessive bandwidth and uses CPU time to generate
dynamic pages. If your website is complex, the site browsing experience
may appear slow to users. It will be even
slower if they have a poor or limited
internet connection. To solve this problem, many web developers build their
web applications as SPAs. It’s called single-page,
but that doesn’t mean your website has
only one page of content. What it means is that there is only one HTML page that gets sent from the
server to the browser, but that page will
update its content as your users interact
with your website. A SPA allows the user
to interact with the website without
the application needing to download
entire new web pages. Instead, it rewrites the current web page as the
user interacts with it. The result is a browsing
experience that feels faster and more
responsive to user input. When the user navigates to the web application
in the browser, the web server returns the necessary resources
to run the application. A SPA has two approaches to
serving code and resources. The first is called bundling, and the second
approach is known as lazy loading or code splitting. With bundling, when the browser requests
the application, the server returns and
loads all necessary HTML, CSS, and JavaScript immediately. With lazy loading,
the browser requests the application and
the server returns only the minimum HTML, CSS, and JavaScript needed
to load the application. Additional resources are
downloaded as required. For example, when a user navigates a specific
section of the application, both approaches are valid. The choice depends on the size, complexity, and bandwidth requirements of the application. For instance, with the
bundling approach, if your application is complex and has a lot of resources, your bundles will grow quite large and take a long
time to download. You could end up
with a site that is slower than a traditional
web application. Let’s explore an example. Imagine you have a site
dedicated to reviewing movies, people never know what to
watch next so you decide to install a feature that randomly suggests the movie for a user. You create a web page that has a what to watch next button. You want to display
a random movie name when the button is clicked. In a traditional website, when the button is clicked, the browser will send a post
request to the web server. The web server returns a new web page containing
the button and movie name. The web browser then
renders the new page. In an SPA, when the
button is clicked, the browser will send a post
request to the web server. The web server will
return a JSON object. The application
reads the object and updates by displaying the
text of the movie name. That’s more efficient
because the rest of the page remains
as it was and it’s content does not need to be sent by the server and
rendered by the browser. But what if you need to
update the majority of the page to display a
different form of content? Well, let’s explore
that scenario. Suppose you are building
a web application that has two pages. One page shows the
latest news and the other page shows the
current user’s profile page. Navigation bar at the top of the site contains a
link to each page. In the traditional websites, when the user clicks
a profile link, the web browser sends the
request to the web server. The web server generates the entire HTML page and sends it back
to the web browser. The web browser then
renders a new web page. In a single-page application, different pages are
broken into templates, also known as views. Each view will have HTML code that can be updated
by the application. For instance, the profile
page would have a username, a first name, and a last name. The web browser
sends the request to the web server and the
web server sends back a file called a
JavaScript Object Notation or JSON object. This contains only the
data to be displayed, such as the user’s first
name and last name, and the SPA will
update the HTML. This is much smaller than
sending an entire web page. The web browser then updates
the web page by inserting the template with items replaced by the values
in the JSON object. For your next website, consider whether its
complexity suits a traditional
multi-page application or would perform
better as an SPA. Remember that a
single-page application has two methods of
delivery resources. Delivering all resources
immediately or delivering resources
dynamically as required. If all resources are delivered when the
application is loaded, the single-page application must include the views for every
page on initial load. If resources are
loaded dynamically, the single-page application
requests the views as required and stores views in the browser for
subsequent requests. Now you can compare some
popular SPA websites to traditional ones and judge the performance
difference for yourself.

Introduction:

In today’s web development landscape, building interactive and dynamic user interfaces is crucial. React, a popular JavaScript library, has emerged as a leading solution for this challenge. This tutorial aims to introduce you to the fundamentals of React and its role in front-end development.

What is React?

React is an open-source JavaScript library for building user interfaces. It focuses on declaratively describing what you want to see on the screen rather than how to achieve it. This declarative approach makes React code easier to understand, maintain, and test.

Key Concepts of React:

• Components: The building blocks of React applications. Each component encapsulates a small, reusable piece of UI with its own logic and state.
• JSX: A syntax extension that allows writing HTML within JavaScript code, simplifying the creation of React components.
• State: Represents the data that drives the UI of a component. Any changes to the state will trigger a re-render of the component.
• Props: Data passed from a parent component to its children, allowing customization and communication between components.
• Virtual DOM: An in-memory representation of the UI that React uses to calculate the most efficient way to update the real DOM, optimizing performance.

Benefits of using React:

• Component-based architecture: Promotes code reusability, modularity, and maintainability.
• Declarative nature: Makes code easier to understand and reason about.
• Performance: Virtual DOM helps in efficient updates and rendering.
• Large community and ecosystem: Provides a rich library of tools, components, and resources.

Getting Started with React:

To learn React, you need basic knowledge of HTML, CSS, and JavaScript. Here are some resources to get you started:

• Official React Documentation: https://legacy.reactjs.org/docs/getting-started.html
• Interactive Tutorial: https://legacy.reactjs.org/docs/getting-started.html
• Create React App: A tool for setting up a new React project: https://create-react-app.dev/
• Online Courses: Numerous platforms like Udemy, Coursera, and Codecademy offer various React courses.

Building your first React application:

Start with creating simple components like buttons, forms, and lists. Gradually move on to building more complex components and integrate them into a complete application. Practice writing clean and efficient code, leverage existing components, and explore the vast ecosystem of React libraries and tools.

Examples of React applications:

• Facebook
• Instagram
• Netflix
• Airbnb
• Dropbox

Beyond the basics:

As you progress with React, explore advanced concepts like state management libraries (Redux, MobX), routing libraries (React Router), and data fetching techniques (Axios). Remember, the React community is constantly evolving, so keep yourself updated with the latest trends and practices.

Conclusion:

With its component-based architecture and declarative nature, React has revolutionized front-end development. By mastering the core concepts and best practices, you can build engaging and interactive web applications. Remember, the journey of learning React is continuous, so embrace the learning process, actively participate in the community, and continue building innovative applications.

You are developing a SPA, or Single Page Application. Why is it beneficial to use React during your development? Choose all that apply from the list below.

Re-use components. Simplify testing. Maintain code in the long term.Write less code to implement functionality in a web browser.

Correct! React allows developers to write less code to implement functionality in a web browser, it helps them maintain code in the long term and simplifies testing, and it also allows developers to re-use components when building their applications.

I’m sure you’ve created
something from scratch before. I bet you realize how challenging it
can be as opposed to using pre made components. Think about the effort that goes into
building a brand new house versus the convenience of constructing a modular
building with pre made components that you just need to put together. React is focused on
working with components, which makes it simple to build functional
user interfaces on web and mobile. And, since React is one of the most
popular JavaScript libraries, it’s important that you can
explain what its purposes and describe how its components work together. Available since 2013 React is an open
source library with a community of core contributors and
companies that maintain it. Developers use React to develop
single page applications and you can also develop mobile
applications with React native. When you develop an app, you can choose to
use React to develop the user interface. But building an application
requires more than that. You must also consider the navigation and how the app will request
data from a web server. Therefore React is used in conjunction
with other JavaScript libraries during development. But what makes React so useful is that it allows developers to
write less code to create functionality. This in turn makes it easier to
maintain code in the long term and simplifies testing. Because it is so
central to front end development, there are many tools that
you can use with the React. These tools can help you understand
how React is running your code and how you can improve performance. Now that you have a better idea of what
React is let me tell you more about Reacts components. The key concept behind
React is that it allows you to define components that you can
combine to build a web application. A component is basically a small piece of
user interface, such as a music player or photo gallery. This component model allows you to do
several things, such as developing and testing parts of their application in
isolation and it also allows you to reuse components across multiple sections
of the application as well. Let’s explore an example. Most Web applications have
user profiles with pictures. Normally several parts of the application
use a version of this profile picture, such as in the navigation
bar beside the user’s name. It could also show in a user search result
along with several other user pictures and the user picture might also display
an instant message notifications. Instead of programming the logic for every instance of a user profile picture
React allows you to create a user icon component that displays a version of
a profile picture every time it is used. You can then reuse this component
throughout the application. Can you imagine how it will
improve your efficiency. There are in fact many open source
libraries that provide pre made components for React projects. For example, if you want to add
a video player to your website, there’s a React component library for
that. Well, maybe you want to embed a map. There’s a React component library for
that too. As the React community grows bigger,
it continues to add new features and improvements continuously. Annual React conferences,
encourage community sharing and introduce upcoming
developments in the library. I hope that in the near future you
might be joining the React community as an active member and as a future React community member you
now know the React libraries purpose and how its components work together to make
life easier for front end developers. After all, why build something from scratch if
the components are already there to use?

Introduction:

React has become a dominant force in the world of front-end development. Its component-based architecture and focus on declarative programming make it a powerful tool for building complex and dynamic user interfaces. In this tutorial, we’ll delve into the inner workings of React, exploring its core concepts and how they come together to create engaging web applications.

Building Blocks of React:

• Components: Reusable, self-contained units that represent a single UI element or functionality.
• JSX: A syntax extension that allows writing HTML within JavaScript, facilitating component creation.
• State: Represents data that drives a component’s behavior and UI. Changes in state trigger re-rendering.
• Props: Data passed from parent components to children, allowing for customization and communication.
• Virtual DOM: An in-memory representation of the UI that React uses to calculate the most efficient way to update the real DOM, optimizing performance.

The React Cycle:

1. Render: React takes the JSX representation of components and creates a virtual DOM tree.
2. State Change: When state changes in a component, React marks that component and its descendants as dirty.
3. Virtual DOM Diff: React compares the new virtual DOM with the previous one to identify the minimal changes needed.
4. Real DOM Update: Only the changed parts of the real DOM are updated, minimizing browser workload and improving performance.

Key Features:

• Declarative: React focuses on what you want to render instead of how to achieve it, promoting clarity and maintainability.
• Component-based: Components encapsulate functionality and make code reusable, modular, and easier to reason about.
• Virtual DOM: Enables efficient UI updates by minimizing unnecessary DOM manipulation, leading to smoother performance.
• Large Community and Ecosystem: Extensive libraries, tools, and resources available for various needs and functionalities.

Learning Resources:

• Official React Documentation: https://legacy.reactjs.org/docs/getting-started.html
• Interactive Tutorial: https://legacy.reactjs.org/docs/getting-started.html
• Create React App: https://create-react-app.dev/
• Online Courses: Platforms like Udemy, Coursera, and Codecademy offer various React courses.

Getting Started:

1. Build Simple Components: Start with basic components like buttons, forms, and lists.
2. Practice Clean Code: Write modular and maintainable code following best practices.
3. Explore Tools and Libraries: Leverage existing components and libraries to accelerate development.
4. Join the Community: Participate in online forums and discussions to learn from experienced developers.

Conclusion:

React’s unique approach to building user interfaces has revolutionized front-end development. By understanding its core concepts and principles, you can unlock its potential and create engaging and interactive web applications. Remember, the journey of learning React is continuous, so stay curious, keep exploring, and embrace the ever-evolving landscape of front-end development.

Indicate the correct process that React uses to ensure that your application is fast and responsive to user input:

React updates the virtual DOM and compares it to the previous version of the virtual DOM. If a change has occurred, only that element is updated in the browser DOM. Changes on the browser DOM cause the displayed webpage to change.

Yes, that’s correct! By keeping the Virtual DOM up to date, only changed elements can be updated in the Browser.

By now you’ve learned, that you can build components in
React to develop user interfaces. But how do React components turn into
the elements on the web page that you use. Remember when your web browser receives
an HTML page, it constructs a DOM, to represent it. But updating the DOM is
considered expensive, because it is very time intensive for
the web browser to do so. Every time the browser DOM is updated, it
causes the browser to re compute the page. Yet many big and popular websites
still load in no time today. How can it be? In this video, I will explain
how React solves the problem, by computing its own virtual DOM. Let’s start with how React components
relate to the website displayed in your browser. A reality component, has a one to one relationship to an HTML
element that is displayed on the webpage. But how does React keep track of which
HTML elements need to be updated. This is where reacts virtual
DOM comes into play. When React builds out
its tree of components, it builds out its own dome in
memory called the virtual DOM. The virtual DOM is a representation of
the browser DOM that is kept in memory. React uses this virtual DOM to update
the browser DOM, only when it needs to. This ensures that your application is
fast and responsive to user input. Let me explain how it works, React
checks to see if the HTML components in the virtual DOM matches the browser DOM. If a change is required,
the browser dome is updated. If nothing has changed,
then no update is performed. This process is called reconciliation. Let’s break down what happens when
you update a component and React. Firstly, the virtual DOM is updated. Then React, compares the virtual DOM to
the previous version of the virtual DOM, and determines which
elements have changed. The changed elements, and only those
elements are updated in the browser DOM. Changes on the browser DOM,
cause the displayed web page to change. In this video, you have learned that,
React constructs and updates a virtual DOM. So that the browser will only
update certain HTML elements, instead of recreating the entire page.

In React, components are the fundamental building blocks for creating user interfaces. They enable developers to create reusable and modular code, making applications easier to maintain and understand. Component hierarchy refers to the way these components are organized and nested within each other to form the overall application structure.

Understanding the Root Component:

Every React application has a single root component, often called the “App” component. This component serves as the parent to all other components in the application. It defines the overall layout and structure of the application.

Nesting Components:

Components can be nested within other components, creating a hierarchy. The child components receive data and functionality from their parent components, allowing for modularity and code reuse.

Example: Shopping List App

Imagine building a simple shopping list app. The root component would be “App”. It would have two child components: “New Item Bar” and “Shopping List”.

• New Item Bar: This component would allow users to add new items to the shopping list.
• Shopping List: This component would display the list of items and allow users to check them off as they are purchased.

The “Shopping List” component would then have multiple child components, each representing a single item on the list. These “Shopping Item” components would be responsible for displaying the item’s name and any other relevant information.

Component Benefits:

• Code Reuse: You can reuse the “Shopping Item” component for every item in the list, eliminating the need to write the same code multiple times.
• Modularization: The components are independent and self-contained, making the code easier to maintain and update.
• Scalability: As the application grows, you can easily add new components to the hierarchy.
• Maintainability: Each component represents a specific functionality, making it easier to identify and fix bugs.

Example: Blog Website

Let’s consider another example: a blog website. The root component would still be “App”. It would have two child components:

• Navbar: This component would display the website’s navigation bar.
• Page: This component would contain the main content of the page, such as the blog posts.

The “Page” component would then have several grandchild components:

• Main Feature: This component would display a large, featured blog post.
• Small Feature: This component would be used multiple times to display smaller blog posts.

The “Small Feature” component would be responsible for displaying a blog post summary and a thumbnail image.

Planning Your Component Hierarchy:

Here are some tips for planning your component hierarchy:

• Identify the main features of your application.
• Break down each feature into smaller, reusable components.
• Consider how components will communicate with each other.
• Use descriptive names for your components.
• Start small and gradually add complexity as needed.

By following these tips, you can create a well-organized and efficient component hierarchy that will make your React applications easier to build and maintain.

Learning Resources:

• Official React documentation: https://legacy.reactjs.org/docs/create-a-new-react-app.html
• Interactive tutorial: https://legacy.reactjs.org/docs/create-a-new-react-app.html
• Create React App: https://create-react-app.dev/
• Online courses: Platforms like Udemy, Coursera, and Codecademy offer various React courses.

Conclusion:

Component hierarchy is a fundamental concept in React development. Understanding how to effectively organize your components will help you create cleaner, more maintainable, and more scalable applications.

Planning an application as a series of components
can be tricky at first, but after doing it a few times, it will become set in nature. We’ve already learned
about the core Internet technologies and
now you know that JavaScript libraries
in React allow you to develop user
interfaces much faster. Isn’t it cool that
you can develop user interfaces so quickly? In this video, you
will learn how the component hierarchy
works in React. Every React application contains
at least one component, the root component
or app component. Components are added to the
app component to build out a tree structure of components that make up the application. Let’s explore an example of how an application might be
structured as components. Suppose your application
is a shopping list of items that needs to be picked
up from the grocery store. At the root we have
the app component. The app component has
two child components, new item bar and shopping list. The new item by component allows us to add new
items to the list. The shopping list component
contains a shopping item, child component for each
item in the shopping list. Even though the item
itself might be different, such as chicken or noodles, it is displayed in the same
manner as other items. Therefore, you can reuse the shopping item component
to display multiple items. When a user takes off the items, the list will update and remove the corresponding shopping
item child component from the shopping
list component. Now that you understand
the component hierarchy, let’s explore how a website can be broken down into components. As an example, I will talk you through a typical blog websites. Normally there is a heading, a menu, and a search bar. You also usually have a
featured blog posts that displays larger than
previous blog post below it. Now, let’s unpack the
component hierarchy. At the root of the
component hierarchy, you have the app component. This is the entire webpage. The app component has
to child components, the Navbar component for the navigation bar and
the Page component. The Navbar component contains
the title of the blog, navigation links
for the website, along with the search component. In the page component, we
have three components. The main feature component and two instances of a small
feature component. The main feature
component displays a blog summary about
a specific blog post. In the small feature component, there is a blog summary
and a thumbnail component to display an image associated
with the blog post. Notice that the small feature
component is used twice. It is the same piece of code, but for the second
small feature, the code uses
different properties. That is exactly the benefit of building a website
with React components, you can reuse code for
multiple sections. Using a series of components to build an application
can be tricky at first, but after you do it a few times, you will appreciate
how handy it is. Good luck with planning your component hierarchies in React.

You’ve reached the end of
this module on UI frameworks, is now time to review what you’ve learned during
these lessons. Over the course of this module, you’ve explored the concepts of UI frameworks and libraries, and covered an
introduction to React. Let’s recap the key points you learned and the
skills you gained. You began the module with an introduction
to UI frameworks. Following the completion
of this first lesson, you should now be able to utilize CSS and
JavaScript libraries, demonstrate a high level
understanding of dependencies, package managers, and
JavaScript bundlers, and explain the
key techniques and concepts of responsive
web design, such as screen resolutions
and fixed and fluid grids. You should also be
able to develop a simple Bootstrap website
with the use of HTML and CSS. Utilize Bootstrap CSS library, including deploying
class in fixes for responsive breakpoints and
class modifiers to change your CSS code and demonstrate
an understanding of Bootstrap’s grid
system by building a web page using
the Bootstrap grid. Following your exploration of UI frameworks and libraries, you then covered an
introduction to React and the JavaScript library for
building user interfaces. Now that you’ve completed
an introduction to react, you should be able
to differentiate between static and
dynamic web page content. List examples of how each type works in the context
of web servers. Explain what a single-page
application is, how it works, and how it differs from traditional
web applications. You should also be able to outline the purpose of React
as a JavaScript library, explain the concept of the
React component model, and identify examples
of common components. Demonstrate a high
level understanding of React components, explain how React
components operate as a hierarchy in order to generate a web page
through the virtual DOM. You’re now familiar
with the basics of UI frameworks and libraries, and the basics of React
and React Native. Excellent. You’ve
made great progress.