Formattemplate

Formattemplate is a generic concept referring to a pattern that defines how data should be formatted into text. It is used to generate user-facing strings, serialized data, or reports by combining fixed literal content with placeholders for dynamic values.

A format template consists of literals and placeholders. Placeholders specify where data should be inserted and may reference an item by position or by name. They can also include a format specifier to control presentation, such as numeric precision, alignment, or date-time formatting. Delimiters and syntax differ by template engine (for example, braces { } with named fields or percent signs in printf-style templates).

Rendering process: the template engine resolves placeholders using a data model, applying any specified formatting, and produces the final string. Some engines support escaping to include literal delimiter characters. Advanced templates may support conditional content, repetition, or localization.

Usage: widely used in report generation, logging, UI rendering, and data export. It helps separate content from presentation, enables reuse of templates, and supports localization by supplying data and formatting rules separate from markup.

Relation and variants: The concept overlaps with format strings and template languages. It contrasts with full programming templates that execute logic; format templates typically aim to present data rather than compute. Common families include printf-style, Python-style str.format, and template engines like Mustache, Jinja, or MessageFormat; each uses its own syntax but shares the core idea of placeholders and format specifiers.