Feature: #96812 - Override backend templates with TSconfig¶

Introduction¶

All Fluid templates rendered by backend controllers can be overridden with own templates on a per-file basis.

This can be configured using TSconfig: Both page TSconfig and user TSconfig are observed. The feature is available for basically all Core backend modules, as well as the backend main frame templates. Exceptions are email templates and templates of the install tool.

This feature was previously available in a similar way for some specifically crafted backend controllers, namely the dashboard extension and the page module. It was based on frontend TypoScript in combination with Extbase magic. This has been superseded by the new TSconfig based approach. Instances using the old solution need an adaption. Please find details in the changelog entry.

Basic syntax¶

The various combinations are best explained by example: The linkvalidator extension (its Composer name is "typo3/cms-linkvalidator") comes with a backend module in the Web main section. The page tree is displayed for this module and linkvalidator has two main views and templates: Resources/Private/Templates/Backend/Report.html for the "Report" view and another one for the "Check link" view. To override the Backend/Report.html with an own template, this definition can be added to an extension's Configuration/page.tsconfig file (see changelog):

# Pattern: templates."composer-name"."something-unique" = "overriding-extension-composer-name":"entry-path"
templates.typo3/cms-linkvalidator.1643293191 = my-vendor/my-extension:Resources/Private/TemplateOverrides

When the target extension identified by its Composer name "my-vendor/my-extension" provides the file Resources/Private/TemplateOverrides/Templates/Backend/Report.html, this file will be used instead of the default template file from the linkvalidator extension.

All Core extensions stick to the general templates, layouts and partial file and directory position structure. When an extension needs to override a partial that is located in Resources/Private/Partials/SomeName/SomePartial.html, and an override has been specified like above to my-vendor/my-extension:Resources/Private/TemplateOverrides, the system will look for file Resources/Private/TemplateOverrides/Partials/SomeName/SomePartial.html. Similar for layouts.

The path part of the override definition can be set to whatever an integrator prefers, Resources/Private/TemplateOverrides is just an idea here and hopefully not a bad one, further details rely on additional needs. For instance, it is probably a good idea to include the Composer or extension name of the source extension in the path (linkvalidator in our example), or when using overrides based on page IDs or group IDs, to include those in the path. The source extension sub-path is automatically added by the system when looking for override files, when a layout file is located at Resources/Private/Layouts/ExtraLarge/Main.html, and an override definition uses path Resources/Private/TemplateOverrides, the system will look up Resources/Private/TemplateOverrides/Layouts/ExtraLarge/Main.html.

Templates overrides are based on file existence: Two files are never merged. An override definition either kicks in because it actually supplies a file at the correct position with the correct file name, or it doesn't and the default is used. This can become unhandy for big template files. In such cases it might be an option to request a split of a big template file into smaller partial files, so an extension can override a dedicated partial only.

When multiple override paths are defined and more than one of them have overrides for a specific template, the override definition with the highest numerical value wins:

templates.typo3/cms-linkvalidator.23 = other-vendor/other-extension:Resources/Private/TemplateOverrides/Linkvalidator
templates.typo3/cms-linkvalidator.2300 = my-vendor/my-extension:Resources/Private/MyOverrideIsBigger

Due to the nature of TSconfig, and its two shapes page TSconfig and user TSconfig, various combinations are possible:

• Define "global" overrides with page TSconfig in page.tsconfig of an extension. This works for all modules, no matter if the module renders a page tree or not.
• Define overrides on page level using the TSconfig field of page records. As always with page TSconfig, sub pages and sub trees inherit these settings from parent pages.
• Define overrides on user or (better) group level. As always, User TSconfig can override page TSconfig by prefixing any setting available as page TSconfig with page. in user TSconfig. So a user TSconfig template override starts with page.templates. instead of templates..

Usage in own modules¶

Extensions with backend modules that use the Simplified backend module template API automatically enable the general backend template override feature. Extension authors do not need to further prepare their extensions to allow template overrides by other extensions.