TemplateEngines

TemplateEngines are software components used to generate text outputs by combining a template with data. They enable separation of presentation from application logic, allowing dynamic HTML, emails, or other text formats to be produced without embedding code directly in templates.

Templates contain placeholders or expressions that are replaced at render time with values from a data model. Most engines support control structures such as conditionals and loops, as well as partials or includes to reuse snippets. Some provide template inheritance or blocks for extending base layouts. Rendering can be server-side, client-side, or at build time, and engines may interpret templates or compile them to executable code for performance.

Key features often include automatic escaping of user-provided content to prevent injection attacks, configurable escaping behavior, and support for custom filters, helpers, or functions that transform data during rendering. Caching of compiled templates is another common optimization to reduce rendering latency. Many engines also offer internationalization support, macros, and the ability to customize syntax or delimiters.

Commonly used template engines span multiple languages. Examples include Jinja2 and Django templates for Python, Handlebars and Mustache for JavaScript, EJS for Node.js, Smarty for PHP, Thymeleaf for Java, and Liquid, which is used in various static and e-commerce platforms.

Template engines are employed in web applications to render views, generate emails, and support static site generation. They provide a versatile, language-agnostic approach to presenting data while keeping code organized and maintainable.