Templating

Templating is a technique for producing text by combining a fixed template with variable data. A template defines structure and presentation, while a template engine fills in the data at render time. Templating is widely used to generate dynamic content such as HTML pages, emails, configuration files, and documents. It helps separate content, layout, and logic, promoting reuse and maintainability.

Templating languages may be logicless or featureful. In logicless templates, the syntax focuses on placeholders and simple sections; more capable engines provide loops, conditionals, and variables, as well as filters, helpers, and blocks. Templates can include partials or includes to reuse components, and support features such as escaping to prevent injection vulnerabilities and template inheritance to extend base layouts.

Data is supplied as a context or model, and the engine renders the final text by replacing placeholders with values and evaluating control structures. Templating emphasizes presentation and data binding while keeping business logic separate.

Common examples include Mustache, Handlebars, Jinja and Django templates for web pages, Liquid for content management, and various template engines in configuration systems. The approach is widely used across languages and frameworks.