Guide 02 · Developer docs

Template languages: Smarty and Twig

Core dna renders server-side sites with Smarty or with Twig, one engine per site, and treats the two as peers. This guide is the one place both are documented: what they share, each engine's language and the platform's additions and limits, the two side by side, and translation.

L1–L2

Unit 03 of 05 5 pages

Twig

Updated 23/10/2026 01:48

The reference for Twig sites, the peer of the Smarty unit: the language as you write it on Core dna, inheritance, includes, embed and macros, what the platform adds and leaves out, and the security position of a Twig site without a sandbox or autoescaping.

Twig is a full peer of Smarty on Core dna, and this unit has the same shape and depth as the Smarty one. It assumes The shared model, and it is written for developers who may know Twig from elsewhere: the places where the platform departs from the upstream manual are called out where they arise.

Begin with Twig in Core dna: autoescaping is off, strict variables are off, and a handful of things the manual takes for granted are not installed. Twig syntax covers output, record attributes, loops and the platform's own set; Twig inheritance, includes, embed and macros covers composition and the template context. What the platform adds to Twig is the reference for the platform's filters and its empty test, and Twig security sets out what a site without a sandbox or autoescaping must review instead, and where translation comes from when there is no translation extension.

In this unit

Read in order

01 Twig in Core dna Core dna runs Twig 3.19 with the string extension, autoescaping switched off, strict variables off, no sandbox and a set tag of its own. How the platform configures it, where Twig files live and what they are called, how it differs from the upstream manual, and where errors and debug output show. 02 Twig syntax: output, attributes and control flow The Twig you write every day on Core dna: printing values and chaining filters, reaching a record's getters and areas as attributes, conditions, loops and tests, and the platform's own set tag, which also stores every value in the template context. Checked against the version the platform runs. 03 Twig inheritance, includes, embed and macros How Twig templates are composed on Core dna: a base template and the blocks a child fills, includes with with and only, embed for parameterised wrappers, macros and import, the template context for state that crosses templates, and whitespace control, with the Smarty equivalent where one exists. 04 What the platform adds to Twig Stock Twig 3.19 plus the string extension, and the platform's own additions: debug_vars, four coercion filters that refuse null, an empty test that never calls a record empty, json_decode and its own set tag. What each one takes, the input that makes it fail, and the standard filters production Twig sites use most. 05 Twig security: no sandbox and no autoescaping Twig on Core dna runs without a sandbox and without autoescaping, and has no translation extension. What each means in practice, how it compares with Smarty's policy, a checklist for reviewing Twig code non-developers can edit, the question to ask before every output, and where translation comes from.