RTE.default.contentCSS is broken in Frontend
The page TSconfig property
RTE.default.contentCSS allows to define one or more CSS files, which are then used by the RTE to style the text inside the RTE. An example is
RTE.default.contentCSS = fileadmin/template/style_rte.css
In the backend this is working correctly.
However, if the RTE is opened from the frontend, then this does not work. The RTE then tries to get the CSS file from a wrong URL.
It seems like the path calculation in rtehtmlarea/Classes/Form/Element/RichTextElement.php, function getContentCssFileNames() does not work correctly.
#4 Updated by Andreas Allacher about 3 years ago
In that regard there are some small differences regarding frontend / frontend editing check in RteHtmlAreaApi and RichTextElement.
There are some methods that basically also do the same, maybe the should be moved in a utility?
e.g. there is a isFrontendEditing check method in both that does the same.
Then there is writeTemporaryFile and getFullFilename.
And there is also differences in those two. getfullFilename checks in RteHtmlAreaApi regarding isFrontend() || isFrontendEditing().
In RichTextElement it only checks for isFrontendEditing.
Also the check in writeTemporaryFile has been improved in RtehtmlAreaApi.
Maybe this issue is realted, would have to test it.
#6 Updated by Chris topher about 3 years ago
In #65705 the problem obviously only exists on FE pages, which contain something that looks like a domain name in the page title. This is not the case for me: My pages do not look like a domain name. Also I have the issue on all pages.
I do use RealURL and I can confirm that config.absRefPrefix is set. So the situation at least is similar to the one in #65608.