JavaScript Templating Engines: Pug, Handlebars (HBS), and EJS
Tags: javascript, webdev, tutorial, node
Published: 2023-12-08 14:52:00

Web development often involves generating HTML dynamically, with JavaScript templating engines making this task more manageable. Let’s explore three popular ones: Pug (formerly Jade), Handlebars (HBS), and Embedded JavaScript Templates (EJS).

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#Pug
Pug is a high-performance template engine heavily influenced by Haml and implemented with JavaScript for Node.js and browsers.

###Advantages:

- **Simplified Syntax**: Pug uses whitespace and indentation, eliminating the need for closing tags.

- **Code Reusability**: Offers mixins and template inheritance.

- **Powerful**: Provides conditional statements, loops, and template inheritance.

###Disadvantages:
- **Learning Curve**: Developers must learn its unique syntax.
- **Error Handling**: Stack traces on errors can be less clear.

###Installation:
Install Pug via npm:
```
npm install pug
```
##Example:
```
doctype html
html(lang="en")
  head
    title= pageTitle
  body
    h1 Pug - node template engine
    #container.col
      if youAreUsingPug
        p You are amazing!
```
---
#Handlebars (HBS)
Handlebars is a logic-less templating engine that dynamically generates HTML pages.

###Advantages:
- **Ease of Use**: Familiar HTML-like syntax.
- **Flexibility**: Custom helpers and partials for reusable code.
- **Compatibility**: Easily integrates with existing code as it builds upon regular HTML.

###Disadvantages:
- **Logic-less Nature**: Lacks direct support for logic, requiring pre-processing before template compilation.
- **Complexity in Large Applications**: Can become hard to maintain in large-scale applications.

###Installation:
Install Handlebars via npm:
```
npm install handlebars
```
##Example:
```
<!DOCTYPE html>
<html>
<head>
  <title>{{title}}</title>
</head>
<body>
  <h1>{{header}}</h1>
  <div>{{body}}</div>
</body>
</html>
```
---
#Embedded JavaScript (EJS)
EJS is a simple templating language that enables the generation of HTML markup with plain JavaScript.

###Advantages:
- **Minimal Syntax**: EJS uses plain JavaScript, making it familiar to many developers.
- **Fast**: Compiles into highly efficient JavaScript functions.
- **Easy Embedding**:Simple to embed and mix with HTML.

###Disadvantages:
- **Potential Messiness**: Mixing JavaScript and HTML can lead to less readable templates.
- **Limitations**: Lack of some features may require additional HTML or JavaScript for certain tasks.

###Installation:
Install EJS via npm:
```
npm install ejs
```
##Example:
```
<!DOCTYPE html>
<html>
<head>
  <title><%= title %></title>
</head>
<body>
  <h1><%= header %></h1>
  <% if (showBody) { %>
    <div><%= body %></div>
  <% } %>
</body>
</html>
```
---

#Performance Comparison

Pug has demonstrated fast rendering speeds and optimization for high performance. Handlebars is known for its efficient template rendering, making it suitable for performance-critical applications. EJS, built with plain JavaScript, also exhibits high performance in generating HTML markup. It’s advisable to consider these performance aspects based on specific project requirements.

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#Real-World Use Cases

Pug has been widely adopted in projects where developers seek a stylized, expressive syntax. Handlebars finds its place in applications where a logic-less yet powerful templating engine is required. EJS, due to its minimal syntax and embedding ease, is favored in projects demanding simplicity and integration with plain JavaScript.

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#Community and Support

Each of these templating engines has vibrant communities offering support, documentation, and libraries. When considering a templating engine for a project, it’s essential to take into account the available support and resources specific to the engine you choose.

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#Best Practices

When utilizing Pug, Handlebars, or EJS in your projects, it’s vital to adhere to best practices for maximizing their benefits. Proper utilization of features like mixins, logic-less templating, or plain JavaScript embedding should be followed to ensure maintainability and scalability.

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#Comparison

Each templating engine has its place in web development. Pug offers a robust set of features for developers who prefer a stylized syntax. Handlebars suits those who need a logic-less yet powerful templating engine, while EJS is perfect for those who want minimal templating with plain JavaScript.
Understanding the differences and applications of Pug, Handlebars, and EJS empowers developers to select the right tools to build efficient, maintainable, and scalable web applications.


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#About the Author

This article was written by mahdi, a web developer with a passion for simplifying complex technical concepts. You can find more of their work on [GitHub](https://github.com/m-mdy-m).