Introduction

What does it do?

The Frontend Theme for Extension Development extension provides a TYPO3 frontend theme for development purposes. Its job is to give a TYPO3 installation a reasonable frontend to look at and to render against, without building a site package for it first.

Important

The theme is not finished. What this chapter describes is what the extension is for; see the note at the end of this section for what it already does.

The situations it is built for, where an extension has to be seen or exercised in a frontend rather than only in a test assertion:

Extension development, to click through what an extension actually outputs instead of reading the rendered HTML in a test failure.
DDEV based test instances of an extension repository, where a throwaway TYPO3 installation needs a frontend rendering pages, navigation and content elements.
Acceptance tests, which need a stable and predictable frontend to drive a browser against.
Reproducing an issue in a minimal installation before debugging it.

Warning

This is a development tool, not a production theme. It is meant to be required as a development dependency of an extension repository or installed into a disposable test instance, and it makes no promise about design, markup stability or upgrade paths for a live site.

Note

The theme renders a page once a site depends on its site set — see Configuration. It covers every classic content element EXT:frontend registers, the eleven menu elements, ten elements of its own, and third-party Extbase plugins, none of which requires fluid_styled_content — that extension is not a dependency here, and on TYPO3 v14 it is not installed at all. It ships five backend layouts, a main menu, a section menu and a breadcrumb, and a light/dark appearance switch. A seeded /styleguide page renders the whole component library on one page, so the theme can be looked at without building content for it first — see Feature: A styleguide page. This chapter is extended along with the implemented features.

Underneath that sits the foundation: TYPO3 v13 and v14 support from one code base with core version aware classes, wired by the dependency injection container of the running TYPO3 version.

Core version aware implementations

Code that has to differ between the supported TYPO3 versions lives below Core13/ and Core14/ in the repository root. Shared code — interfaces, abstract base classes and everything working on both core versions — lives in Classes/.

Only the directory matching the running TYPO3 version is registered in the dependency injection container, so a service asking for an interface always receives the implementation matching the current core version.

Compatibility

Branch	Extension	TYPO3	PHP
main	2.x	v13.4 / v14.3	8.2 - 8.5
1	1.x	v12.4 / v13.4	8.1 - 8.4

This manual documents the main branch. Branch 1 is the maintained line for the previous core version tuple and has a manual of its own; PHP 8.1 is supported there for TYPO3 v12 only, because TYPO3 v13.4 requires PHP 8.2.

Contributing

Contributions are welcome. The development setup, the quality gates and the commit message rules are described in the CONTRIBUTING.md file of the source repository.