Importing themes filepath error

[Ruudt]

When importing themes that were created for older Contao installations the relative filepaths can be wrong because the earlier versions had the CSS files in the Contao root dir. In Contao 3 the path probably changed again, so a unified way of exporting and importing might prevent frustration....

Related to #2882

[xchs]

Not only the file path might be wrong, occasionally also the database structure could have been changed meanwhile. Therefore, it is usually better to install/import the theme in that Contao version, for which it was created and to perform the update procedure to a recent version in a second step.

[Ruudt]

It would be great if the update scripts can also be applied to themes before they are imported. Though that is probably hard to do... Perhaps using temporary tables? At least I'd say that importing a theme not having to worry much about where it came from. To you and me it won't be an issue, but don't we want the public to start using Contao as well?

[xchs]

Yes, of course we want this. An update routine for (older) themes would be definitely great, but certainly not that easy to implement (I guess).

Actually, I think it's a pity that the generated theme XML data file does not contain the (minor) version number of those Contao installation for which it was created.

For instance, I have some CTO files, where I do not remember exactly on which version these themes were exported.

That is, it would be reasonably helpful if (at least) the theme importer could somehow show this information (e.g. version number, creation date, etc.) in the first step and to inform/advice the user about potential problems and glitches that may occur (or to suggest a certain "best practice").

[leofeyer]

I don't know if this is possible, but I will look into it.