Top 5 Best JavaScript Template Engines
Template engines help in the decoupling of HTML and JavaScript code to reduce the client-side code complexity and make it manageable. Once you know the advantages of the template engines, you will definitely fall in love with them and start using them right away. You will be immensely impressed by their features and the benefits they bring to client-side development. It can easily save your countless hours to build a website or an app. There are lots of problems that you come across at the time of client-side development like:
- Mixing of HTML and JavaScript code which makes code unmanageable, messy, increases the page size, and makes fixing bugs difficult.
- Creating HTML dynamically in JavaScript code, which is very painful.
- String concatenation being very irritating and cumbersome work to do.
- In plain HTML you can’t use variables, mixins, or conditions to manipulate the HTML.
- Clear violations of separate view generation.
A good template engine can address all these problems.
A template engine is a library or a framework that has its own set of rules/languages to interpret the data in a view. It helps in:
- Implementing separate view generation processes.
- Cleaning HTML and JavaScript code. JavaScript code can be part of a different file.
- Decoupling of HTML and JavaScript code.
- Reusing templates for creating multiple dynamic pages.
- An effective way of doing string interpolation.
- Making HTML more powerful with the use of variables, conditional operators and other programming concepts.
- Saving times for creating views.
As a template engine is a useful tool, there are many template engines existing today, which makes it difficult to choose the right one. This post talks about the best, top 5 template engines. These template engines were chosen based on their popularity, simplicity to learn and code, being actively maintained, and having great community support. Let’s begin.
1. Handlebars.js
Handlebars provides the power necessary to let you build semantic templates effectively with no frustration. Handlebars.js is an extension of the Mustache JavaScript templating language. In general, the syntax of the Handlebars.js template is a superset of Mustache templates. It has the following advantages,
- Handlebars is a logic-less templating engine. Logic-less templates help to build templates with ease and without adding any complexity. Handlebars is logic-less as you cannot execute JavaScript inside templates. The logic resides in JavaScript files, which keeps your HTML clean.
- Using the Handlebars precompiler, you can precompile your Handlebars templates to save time on the client and reduce the required runtime size of the handlebars library.
- Handlebars compiles a template only once. Once compiled, it generates a JavaScript function that can be executed repeatedly without re-parsing the template.
- Handlebars is already used by some of the popular client-side frameworks like Ember.js and Meteor.js. It also has great community support!
2. Mustache
Mustache is a “logic-less” template engine. It is named "Mustache" because of a heavy use of curly braces, { }, that resemble a sideways mustache. It is described as a "logic-less" system because there are no messy if ... then or looping constructs embedded within a Mustache template. However, both looping and conditional evaluations can be achieved using section tags, processing lists, and lambdas. In Mustache, there are only tags. Some tags are replaced with a value, some nothing, and others a series of values.
Another advantage of Mustache is that it is not tied to any particular language. Mustache is implemented in different languages: Ruby, JavaScript, Python, PHP, Perl, Objective-C, Java, .NET, Android, C++, Go, Lua, Scala, etc. Mustache.js is the JavaScript implementation.
3. EJS
“E" is for "effective"! EJS is a simple templating language that lets you generate HTML markup with plain JavaScript. No religiousness about how to organize things and no reinvention of iteration and control-flow. It uses just plain JavaScript. It features:
- Fast compilation and rendering
- Simple template tags: <% %>
- Custom delimiters (e.g., use <? ?> instead of <% %>)
- Both server JavaScript and browser support
- Static caching of intermediate JavaScript
- Static caching of templates
- Complies with the Express view system
EJS has a large community of active users, and the library is under active development.
4. NunJucsks
https://mozilla.github.io/nunjucks/
Built by Mozilla, Nunjucks is a full-featured templating engine for JavaScript. Nunjucks has a powerful language with block inheritance, auto escaping, macros, includes, layout inheritance, asynchronous control, and more. It is pretty lightweight: only 8K gzipped runtime with precompiled templates in the browser. Its lightweight ability makes it fast, lean, and high-performance. It is easily extendable with custom filters and expressions. Nunjucks can be used for client-side rendering and also with Node.js to compile templates server-side. This allows you to prerender complex pages, and use the same templates to change the page when your application receives new data. You can also precompile your templates for production. It has zero dependencies, so loading it in the browser is faster as it doesn't load anything else.
5. Pug (Previously known as Jade)
Pug is a high-performance template engine heavily influenced by Haml and implemented with JavaScript for Node.js and browsers. This project was formerly known as "Jade". "Jade" being a registered trademark, it was renamed to Pug. Pug is a clean, white space/indentation-sensitive syntax for writing HTML. Therefore, one needs to be careful to follow the proper syntax. Pug has some really neat features, allowing you to write modular and reusable markup. Native JavaScript is used to write the logic in Pug, that means there's less of a learning curve and it becomes easier for developers to speed up. Pug also allows embedding regular JavaScript code directly within the template. In addition to JavaScript, you can reuse Pug templates in Scala, PHP, Ruby, Python, and Java.
Conclusion
Templating engines are a great tool to have in your kitty. This post gives you an overview of the top 5 JavaScript-based template engines. These template engines are powerful and simple to use. These template engines offer different functionalities and different ways of generating a template, but do the job for you. These are the most popular and actively-maintained template engines. It’s important to choose the right template engine, otherwise it can be very problematic. While choosing the right template engine, you need to consider speed, performance, simplicity to use, and ease of learning.
