Deprecation: #99050 - TypoScript _CSS_PAGE_STYLE and config.removePageCss

See forge#99050

Description

Integrators can use the TypoScript setup plugin-level property _CSS_PAGE_STYLE to define custom CSS that is loaded in the frontend. To suppress this output, the additional property config.removePageCss (or somePageObject.config.removePageCss) can be used.

Handling of both plugin-level _CSS_PAGE_STYLE and config object level property removePageCss have been marked as deprecated in TYPO3 v12 and will be removed in v13.

Impact

Using a TypoScript property like plugin.tx_myPlugin._CSS_PAGE_STYLE or the config property removePageCss in config.removePageCss or in a page-specific usage like myPage.config.removePageCss triggers a deprecation level log entry.

Affected installations

TypoScript property _CSS_PAGE_STYLE is a relatively rarely used property in TYPO3 instances. Instances can use the Template backend module to scan for usages.

Migration

Integrators should avoid using _CSS_PAGE_STYLE on plugin level. They should switch adding CSS on a PAGE level. A direct replacement looks like this:

Before:

plugin.tx_myPlugin._CSS_PAGE_STYLE (
    .myClass { text-align: center }
)

After:

page.cssInline {
    10 = TEXT
    10.value (
        .myClass { text-align: center }
    )
}

As a general note, the PAGE property includeCSS is often better suited to include CSS as files, especially when frontend CSS is generated by some processor like SCSS.