The shared model

01 Two engines, one platform A Core dna site renders its templates with Smarty or with Twig, chosen by one site setting. What that setting changes (syntax, the helpers the platform registers, the security model), the much longer list of what it does not, and what happens to a template written for the other engine.

02 Template resolution order Every template name is looked up in three folders, the site's own first, and the first match wins, in both engines. How one request resolves, how a site replaces a platform template by putting a file at the same path, why there is no frontend segment in the path, and what a missing template looks like.

03 Which template renders a record A record is rendered by the template its layout names, not by one tied to its URL or route. Which records follow their layout and which never do, what a controller falls back to, why two pages side by side can render with different templates, and how to find out which template is in play.

04 Global template variables Besides the record it renders, every front-end template receives the same platform helpers, named with a leading underscore: the request, the response, URLs, the site, the visitor, menus, queries and translation. The full list, what each is for, and which exist only for a signed-in visitor.

05 Response models A template never holds a record itself: it holds the record's response model, which lets through only the get, has and is methods its class lists. The list is the template's API in both engines. A real one, what each engine does with a call that is not on it, how to see the list, and who can add to it.

06 Rendering a template from a string Template code typed into the admin, in jobs, discount conditions, shipping methods and search facets, is rendered by the site's engine from a string rather than a file. Where the platform does it, the variables each place supplies, what happens when the code fails, how it differs from a file, and the review it needs.

07 Compilation and caching Both engines compile templates to PHP and keep the result in the site's cache folder on production, and recompile on every request elsewhere. Where compiled templates live, what clears them, the one difference between the engines that matters on production, and how this differs from the page cache.

08 Choosing an engine for a new site The criteria that should decide between Smarty and Twig for a new site: the team's familiarity, translation, who edits template code, and what the rest of the estate uses. Why speed is not one of them, why a site cannot mix the two, and which unit to read next.

Objects ReferenceGenerated from the platform, so it is always current

API ReferenceEvery REST endpoint, in cURL, PHP, Python and JavaScript

In this unit