Flask is a lightweight and flexible micro-framework for Python that makes it easy to get started with web development. It’s designed to be simple and minimalistic, offering essential tools and features needed for building a web application, while allowing developers to have full control over how to implement additional features.

It is a “micro-framework,” which means it doesn’t require specific tools or libraries. This gives developers the freedom to decide how they want to extend their application, making Flask a good choice for those who prefer flexibility and customization. If you’re coming from PHP, this could be an alternative to using other micro-frameworks like Slim. If you’re coming from Ruby, you might find Flask similar to Sinatra.

Let’s see how we can get started with Flask and build a simple web page.

Install Flask

First, we need to install Flask. We can do this by running:

pip install flask

Create the App File

Next, we need to create a Python file, for example, app.py. To get started, we add the following code:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def home():
    return "Hello Flask!"

The Flask class is used to create an instance of the app. The @app.route('/') decorator maps the homepage URL, /, to the home function, which returns the message “Hello Flask!”.

Run the App

Now, run the app using the following command:

flask run --debug

When we visit http://127.0.0.1:5000/ in the web browser, we’ll see the message “Hello Flask!”.

In this case, we also run the app in debug mode, which automatically reloads the server when you make changes to the code. This is useful for development, as you can see the changes immediately without having to restart the server. Keep in mind that you’d want to disable debug mode when deploying your application to a production server.

Routing

One of the main features provided by Flask is routing. Routing is the process of mapping URLs to functions that handle requests. In the example above, we defined a route for the homepage using the @app.route('/') decorator. This tells Flask to call the home function when the user visits the homepage URL, /.

We can define routes for other pages as well. For example, to create an About page, we can add the following code:

@app.route('/about')
def about():
    return "This is the About page."

Now, if we load http://127.0.0.1:5000/about, we’ll see the message “This is the About page.”.

Wrapping up

Flask is a great choice for both beginners and experienced developers, especially when you want flexibility without the complexity of larger frameworks like Django.

In this article, we’ve covered the basics of how Flask works with some simple examples such as how to spin up the development server, and we learned a bit about routing in Flask to create static pages. In future articles, we’ll explore more advanced topics like rendering templates, working with forms, handling requests, and connecting to databases.

So stay tuned!

The post Getting Started with Flask appeared first on Hongkiat.

When developing a Laravel application, having a reliable local development environment is as important as the code itself. A good local development environment can help you work more efficiently, test your code, and avoid potential deployment issues.

There are several tools available within the Laravel ecosystem, such as Homestead, Valet, Sail, and Herd, as well as tools outside their ecosystem like MAMP.

Each tool offers unique features and benefits, catering to different needs and workflows. In this article, we’ll compare these tools to help you choose the best one for your local Laravel development.

Homestead

Laravel Homestead is an official Vagrant box that provides a ready-to-use development environment with PHP, Nginx, MySQL, and Redis pre-installed.

Homestead runs on a virtual machine, ensuring that your development setup is consistent, no matter where you work, and does not affect configurations or other applications on your machine. Homestead also supports multiple PHP versions, making it easy to switch between them. You can configure and manage your setup using a simple Homestead.yaml file.

Homestead is a great option for developers working on projects that require a full-featured virtual machine. Otherwise, lighter options might be preferable.

Pros

• Provides a full-featured development environment out of the box
• Isolated environment prevents conflicts with other local software
• Supports multiple sites and projects

Cons

• Requires Vagrant and VirtualBox, which can be resource-intensive
• Setup can be more complex compared to other tools

Valet

Laravel Valet is a lightweight development environment designed for macOS users. It automatically sets up your Mac to run Nginx in the background and uses DnsMasq to route requests on the *.test domain to your local sites.

Though it is not intended as a replacement for more robust environments like Homestead, it offers a quick, flexible setup. It also supports a variety of other frameworks and CMSs, such as WordPress, Symfony, and Drupal, straight out of the box.

It is perfect for macOS users who prefer a fast and lightweight setup with minimal configuration.

Pros

• Lightweight and fast, with minimal resource usage
• Supports multiple PHP versions
• Seamless integration with other tools like Ngrok and Expose to share your local sites

Cons

• Limited to macOS
• Apache is not supported
• Less isolation compared to virtualized environments, which may cause conflicts with other software on your machine

Sail

Laravel Sail is a Docker-based development environment that provides a simple command-line interface for interacting with Docker.

It comes with pre-configured services like MySQL, Redis, MeiliSearch, and more, making it easy to get started with Laravel projects. Since it is based on Docker, you can easily configure your environment or add any other services that you may need but are not included by default through the compose.yml file.

It is best for developers who prefer Docker-based workflows and want an easily configurable environment.

Pros

• Consistent development environment across different platforms: Windows, macOS, and Linux
• Fast and simple CLI to start and stop projects
• Easily customizable

Cons

• Requires Docker, which can be complex for beginners
• Requires WSL to run on Windows
• Performance can be an issue on some systems

Herd

Laravel Herd is a desktop app designed to create a fast, lightweight, and user-friendly local development environment for Laravel applications. It offers a simple, zero-configuration setup and includes everything you need to get started, such as Composer, the Laravel installer, a debugger, and essential services like MySQL.

Additionally, Herd provides a seamless migration tool from Laravel Valet, and it allows you to manage different versions of Node.js and PHP. You can also manage SSL certificates and other services easily through its user-friendly interface.

A great application if you prefer ease of use with a nice UI.

Pros

• Comes as a desktop app with a user-friendly interface
• Lightning-fast since it directly includes the PHP and Composer binaries
• Node.js and SSL management

Cons

• Limited to macOS
• Full features only available in the paid version

MAMP

MAMP is a popular tool for creating a local server environment on macOS and Windows. While it’s not specifically designed for Laravel, you can configure MAMP to run Laravel applications.

It provides an easy way to set up PHP, MySQL, and Apache or Nginx, as well as other tools on your local machine. It also includes features like PHP version switching and a user-friendly interface. This makes it a convenient option for developers who want to work on Laravel projects and other PHP projects without needing to install and configure everything manually.

Suitable for those who need a cross-platform solution and work with various PHP applications outside Laravel.

Pros

• Simple and user-friendly interface
• Suitable for various PHP applications, not just Laravel
• Supports both Apache and Nginx

Cons

• Less tailored to Laravel-specific needs, so manual configuration might still be required in some cases

Conclusion

Choosing the right tool for running Laravel on localhost depends on your development needs, preferences, and operating system. Consider your specific requirements and workflow to choose the best option for your Laravel development.

The post Laravel Development Environment Compared appeared first on Hongkiat.

Whether you’re new to CSS or have years of experience, you’ve likely encountered pseudo-classes. The most commonly recognized pseudo-class is probably :hover, which allows us to style an element when it’s in the hover state, such as when a mouse pointer hovers over it.

Building on concepts from our previous discussions on margin:auto and CSS Floats, this post provides a detailed examination of pseudo-classes. We’ll explore what pseudo-classes are, how they function, how they can be categorized, and how they differ from pseudo-elements.

Understanding Pseudo-Classes

A pseudo-class is a keyword added to CSS selectors to define a specific state of an HTML element. You can add a pseudo-class to a CSS selector using the colon syntax :, like this: a:hover { ... }.

A CSS class is an attribute applied to HTML elements to enforce the same style rules, such as for top menu items or sidebar widget titles. Essentially, CSS classes group or classify HTML elements that share common traits.

Pseudo-classes are similar to CSS classes because they also apply style rules to elements with shared characteristics. However, while standard classes are user-defined and visible in the source code (e.g., <div class="myClass">), pseudo-classes are applied by user agents (e.g., web browsers) based on the current state of the HTML element.

Pseudo-classes and pseudo-elements can be used in CSS selectors but do not exist in the HTML source code. Instead, they are “inserted” by the user agent under certain conditions for use in style sheets. – W3C

The Role of Pseudo-Classes

The purpose of regular CSS classes is to classify or group elements. Developers group elements based on intended styling, creating classes like “menu-items,” “buttons,” or “thumbnails” to ensure consistent design across similar elements. These groupings are based on characteristics defined by the developers.

For example, a developer might use a <div> as a thumbnail and classify it with a “thumbnail” class.

 <div class="thumbnail">[...]</div>

However, HTML elements possess inherent characteristics based on their state, position, nature, and interaction with the page and user. These traits are not typically marked in HTML code, but can be targeted with pseudo-classes in CSS. Examples include:

• An element that is the last child within its parent element
• A link that has been visited
• An element that has gone fullscreen

These are the types of characteristics typically addressed by pseudo-classes. To better understand the difference between classes and pseudo-classes, let’s consider using the class .last to identify the last elements in various parent containers.

 <ul>
 <li>item 1</li>
 <li>item 2</li>
 <li>item 3</li>
 <li class="last">item 4</li>
 </ul>
 
 <select>
 <option>option 1</option>
 <option>option 2</option>
 <option>option 3</option>
 <option class="last">option 4</option>
 </select>

You can style these last-child elements with the following CSS:

 li.last {
   text-transform: uppercase;
 }
 
 option.last {
   font-style: italic;
 }

But what happens when the last element changes? You’ll need to manually update the .last class from the previous last element to the new one.

This hassle of updating classes can be avoided for certain common characteristics. For example, using a predefined :last-child pseudo-class is highly beneficial. With this, there’s no need to mark the last element in the HTML code, and you can still style it with the following CSS:

 li:last-child {
   text-transform: uppercase;
 }
 
 option:last-child {
   font-style: italic;
 }

Main Types of Pseudo-Classes

CSS offers a variety of pseudo-classes that allow developers to target elements based on specific characteristics that might otherwise be difficult to access. You can find a comprehensive list of standard pseudo-classes on MDN.

1. Dynamic Pseudo-Classes

Dynamic pseudo-classes are applied to HTML elements dynamically, based on the state they transition into due to user interactions. Some examples include :hover, :focus, :link, and :visited, all of which are commonly used with the <a> anchor tag.

 a:visited {
   color: #8D20AE;
 }
 
 .button:hover,
 .button:focus {
   font-weight: bold;
 }

2. State-Based Pseudo-Classes

State-based pseudo-classes are applied to elements when they are in a specific static state. Common examples include:

• :checked for checkboxes (<input type="checkbox">)
• :fullscreen to target any element currently displayed in full-screen mode
• :disabled for elements that can be disabled, such as <input>, <select>, and <button>.

The :checked pseudo-class is particularly popular, as it indicates whether a checkbox is selected.

 .checkbox:checked + label {
   font-style: italic;
 }
 
 input:disabled {
   background-color: #EEEEEE;
 }

3. Structural Pseudo-Classes

Structural pseudo-classes target elements based on their position within the document structure. Some of the most commonly used examples include :first-child, :last-child, and :nth-child(n). These can be used to style specific child elements based on their position within a container. Another example is :root, which targets the highest-level parent element in the DOM.

4. Miscellaneous Pseudo-Classes

There are also pseudo-classes that don’t fit neatly into other categories, such as:

• :not(x), which selects elements that don’t match the specified selector x
• :lang(language-code) for targeting elements based on the language of their content
• :dir(directionality), which selects elements with content in a specific directionality (e.g., left-to-right or right-to-left).

 p:lang(ko) {
   background-color: #FFFF00;
 }
 
 :root {
   background-color: #FAEBD7;
 }

nth-child vs nth-of-type Pseudo-Classes

One of the most challenging aspects of pseudo-classes is understanding the difference between the :nth-child and :nth-of-type pseudo-classes.

Both of these are structural pseudo-classes that target specific elements within a parent element (container), but they do so in distinct ways.

Assume n is 2. The :nth-child(n) selector targets an element that is the second child of its parent element, regardless of the type of element. On the other hand, :nth-of-type(n) targets the second occurrence of a specific type of element (e.g., a paragraph) within the parent element.

Let’s take a look at an example to illustrate this difference:

 /* Styles the second child element inside its parent, which can be of any type */
 p:nth-child(2) {
   color: #1E90FF; /* Light blue */
 }
 
 /* Styles the second paragraph inside its parent element */
 p:nth-of-type(2) {
   font-weight: bold;
 }

Now, let’s see how this CSS affects the HTML in two different scenarios.

Case 1

In Case 1, the second element inside a <div> is an unordered list, so the :nth-child(2) rule does not apply to the paragraphs. Although the unordered list is the second child, it is not a paragraph.

If, however, the parent element contains a second paragraph, the :nth-of-type(2) rule will apply, since this rule specifically targets <p> elements and ignores other types of elements (like unordered lists) within the parent element.

In our example, the :nth-of-type(2) rule will style the second paragraph, which is Child 3 in this case.

 <!-- Case 1 -->
 <div>
   <p>Paragraph 1, Child 1</p>
   <ul>Unordered List 1, Child 2</ul>
   <p>Paragraph 2, Child 3</p>
 </div>

Case 2

In Case 2, we move the unordered list to the third position, placing the second paragraph before it. Now, both the :nth-child(2) and :nth-of-type(2) rules will apply, as the second paragraph is both the second child of its parent <div> and the second <p> element.

 <!-- Case 2 -->
 <div>
   <p>Paragraph 1, Child 1</p>
   <p>Paragraph 2, Child 2</p>
   <ul>Unordered List 1, Child 3</ul>
 </div>

To explore the differences between :nth-child and :nth-of-type further, CSS Tricks has a great post on the topic. If you use SASS, Family.scss can help you create complex nth-child based elements.

Pseudo-Classes vs Pseudo-Elements

When discussing pseudo-classes, it’s crucial to understand how they differ from pseudo-elements to avoid confusion.

Pseudo-elements, like ::before and ::after (see this tutorial on how to use them), are also added by user agents and can be targeted and styled with CSS in a manner similar to pseudo-classes.

The key difference is that pseudo-classes are used to select HTML elements that already exist in the document tree, though they may not be explicitly marked, while pseudo-elements allow us to style elements that don’t typically exist in the DOM on their own. Examples include ::before and ::after, or parts of existing elements like ::first-letter and ::placeholder.

There is also a difference in syntax: pseudo-elements are generally written with double colons ::, while pseudo-classes use a single colon :. This can be confusing because, in CSS2, pseudo-elements were also marked with a single colon—browsers still support this older syntax.

Additionally, there are differences in how we can target pseudo-classes and pseudo-elements with CSS.

1. Their Place in the CSS Selector Sequence

Pseudo-elements must appear after the sequence of selectors, while pseudo-classes can be positioned anywhere within the CSS selector sequence.

For instance, you can target the last list item in a <ul> element in two different ways:

<ul>
  <li class="red"></li>
  <li></li>
  <li class="red"></li>
  <li class="red"></li>
</ul> 

ul > :last-child.red {
  color: #B0171F;
}

OR

ul > .red:last-child {
  color: #B0171F;
}

The first selector targets the last child inside the <ul> element that has the class .red, while the second selector targets the last child among the elements that possess the .red class inside <ul>. As you can see, the position of the pseudo-class can vary.

Let’s attempt something similar with pseudo-elements.

ul > .red::after {
  display: block;
  content: 'red';
  color: #B0171F;
}

The CSS above is valid, and the text “red” will appear after the <li> items with the class .red.

However, the following code will not work because we cannot change the position of a pseudo-element within the selector sequence.

ul > ::after.red {
  display: block;
  content: 'red';
  color: #B0171F;
}

2. Number of Occurrences in a Selector Sequence

Only one pseudo-element can be used per selector, whereas pseudo-classes can be combined as long as the combination makes sense. For example, to target first-child elements that are also read-only, you can combine the pseudo-classes :first-child and :read-only as follows:

:first-child:read-only {
  color: #EEEEEE;
}

jQuery Selector Extensions

Not all selector syntax that includes a : is a proper CSS pseudo-class. If you’ve used jQuery, you might be familiar with selectors like $(':checkbox'), $(':input'), and $(':selected').

It’s important to note that these are not CSS pseudo-classes being targeted by jQuery. Instead, they are known as jQuery selector extensions.

jQuery selector extensions allow you to target HTML elements with simpler keywords. Many of these extensions are shorthand for combinations of standard CSS selectors, represented by a single keyword.

/* Change the font of all input-related HTML elements,
   like button, select, and input */
 
$( ":input" ).css("font-family","courier new");

The post Comprehensive Guide to CSS Pseudo-Classes and Their Usage appeared first on Hongkiat.

One popular layout style on the web is the masonry layout, often used in image galleries and portfolio websites to display images or items of varying sizes.

Traditionally, creating a masonry layout required JavaScript libraries, such as the popular Masonry.js by DeSandro and MiniMasonry. However, with CSS Grid, you can now create this layout using pure CSS.

In this article, we will explore what a CSS Grid masonry layout is and provide some examples to help you understand how it works. Let’s get started.

Getting Started

CSS Grid is a native CSS layout system that provides a grid-based framework where you can define rows and columns and place items within this grid. The masonry layout can be created by combining CSS Grid with certain properties that allow items to span multiple rows or columns, creating the masonry effect. Let’s start with a simple example to understand the basics of creating a masonry layout using CSS Grid.

First, we have the HTML. We have a container with eight items. Each item has a different height and width so that we can see the masonry effect more clearly.

<div class="masonry">
    <div class="gallery">
        <figure>
            <img src="images/image-1.jpg" width="600" height="1200" />
        </figure>
    </div>
    <div class="gallery">
        <figure>
            <img src="images/image-2.jpg" width="400" height="200" />
        </figure>
    </div>
    // 6 more items...
</div>

And, the CSS, as follows:

.masonry {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    grid-template-rows: masonry;
    gap: 10px;
}
// More stylistic styles...

The grid-template-columns property defines six equal columns, the gap property adds space between the grid items, and the grid-template-rows: masonry; property creates the masonry layout based on the available space within the grid container.

You can adjust the layout behavior using the masonry-auto-flow property. When set to next, this property displays items in order along the grid axis instead of placing them in the track with the most free space. As shown below, the items are placed in order from left to right, top to bottom, regardless of the available space.

Making It Responsive

One of the advantages of using CSS Grid is that it allows you to create responsive layouts with ease. You can use media queries to adjust the grid layout based on the screen size. For example, you can change the number of columns in the grid based on the screen width to ensure that the layout looks good on different devices.

@media (max-width: 1200px) {
    .masonry {
        grid-template-columns: repeat(4, 1fr);
    }
}
@media (max-width: 640px) {
    .masonry {
        grid-template-columns: repeat(2, 1fr);
    }
}

You can also change the repeat() value to use auto-fill and minmax() functions to create a responsive layout that automatically adjusts the number of columns based on the available space. The minmax() function allows you to set a minimum and maximum size for the columns, ensuring that they don’t get too small or too large.

.masonry {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    grid-template-rows: masonry;
    gap: 10px;
}

That’s it! You now have a responsive masonry layout that adjusts based on the screen size. You can experiment with different values for the minmax() function and the gap property to achieve the desired layout for your project.

Browser Support

It’s important to note that CSS Grid with the masonry layout is still in the experimental stage and not yet supported in mainstream browsers.

As shown in the table, you can view the masonry layout in the Safari Technology Preview or Firefox.

If you’re using Firefox, type about:config in the address bar, search for the configuration name, and set it to true. The update will take effect immediately, so you can refresh the page without needing to restart the browser.

The status of browser support may change, so it’s a good idea to check the latest updates from the respective browser documentation or support pages.

Wrapping Up

The CSS Grid masonry layout is a powerful tool that allows you to create complex grid-based layouts with ease. By combining CSS Grid with media queries and other CSS properties, you can create responsive masonry layouts that look great on all devices. While the masonry layout is still in the experimental stage, it is worth experimenting with to see how it can benefit your projects.

Last but not least, here’s a CodePen demo for you to try out. Enjoy!

See the Pen CSS Grid Masonry by HONGKIAT (@hkdc) on CodePen.

The post Native CSS Masonry Grid appeared first on Hongkiat.