Unlock the Power of Dynamic HTML Pages with Express.js and Template Engines
When it comes to building server-side applications, rendering static websites from a server can be limiting. Code duplication and inflexibility, especially when working with databases, can hinder development. Fortunately, Express.js provides a solution through template engines, allowing you to create dynamic HTML pages with ease.
How Template Engines Work
A template engine is a simple yet powerful tool that enables you to create reusable components called partials. By declaring variables in your template file and assigning values to them at the appropriate route, you can compile your templates in real-time. This approach prevents code duplication and makes changes easier to implement.
Popular Template Engines for Express
There are several template engines available, including Pug, EJS, Handlebars, Mustache, and Swig. In this article, we’ll explore three popular options: Pug, EJS, and Handlebars.
Getting Started with Express and Template Engines
To begin, set up a new npm project and install Express. Create a src folder and add an app.js file, as well as a views folder to hold your template files. Within the views folder, create a partials subfolder to store reusable components.
Integrating Template Engines into Your Express Application
Integrating a template engine into your Express application requires only a few lines of code. After assigning the Express function, add the following app settings:
views: The directory where your template files are located.view engine: Your chosen template engine (e.g., Pug, EJS, or Handlebars).
Pug: A Unique Syntax for Dynamic HTML Pages
Pug has a distinct syntax that favors indentation and spaces over traditional HTML tags. Variables can be defined using the equals sign (=) or the #{variable} syntax. To render a Pug template in Express, install the Pug package and register it as your preferred template engine.
Using Partials in Pug
Create a reusable nav file called _nav.pug in the partials subfolder. You can then include the partial in your index.pug file using the include keyword.
EJS: A More Familiar Syntax for Dynamic HTML Pages
EJS retains the traditional HTML syntax, using angle brackets and the percent sign to declare variables. Variables can be escaped using <%= name %> or output without escaping using `<%- name %>. To integrate EJS into your Express application, install the EJS package and switch the app view engine setting from Pug to EJS.
Using Partials in EJS
Create a _nav.ejs file in the partials subfolder and add the nav code. You can then include the partial in your index.ejs file using the include keyword.
Handlebars: A Simple and Powerful Template Engine
Handlebars uses a simple syntax, inserting variables using two braces ({{variable}}) or three braces for HTML-unescaped characters. To integrate Handlebars into your Express application, install the hbs package and set the view engine to hbs.
Using Partials in Handlebars
Create a _nav.hbs file in the partials folder and add the nav code. Register your partials in Handlebars using the registerPartials method, and include the partial in your index.hbs file using the {{>partialname}} syntax.
Conclusion
Template engines are a powerful tool for building dynamic web applications with Express.js. With minimal setup and boilerplate code, you can create reusable components and render dynamic HTML pages with ease. Explore the official documentation for each template engine to learn more and start building your next project today!