[development] Switching themes in modules

[Gordon Heydon]

Hi,

I have done a bit of work in this area for a client, and basically what 
happens is that you can change the $custom_theme at time time up until 
the first theme() is called.

When the first theme() is called it will run the theme_init() which will 
load the theme. So it will look at $custom_theme and other places and 
load it.

The problem that I found a lot of contrib modules during hook_menu() 
will call theme() to do something that is not theme related or add the 
css to the page, and the theme will be set.

The problem is with a lot of contrib modules calling theme() far too early.

Gordon.

Olav Schettler wrote:
> I have written a smallish module (http://drupal.org/project/manage) to 
> provide a separate theme for administration pages. It works nicely by 
> setting $custom_theme and providing some settings for a custom menu and 
> selecting on which pages to apply the theme switch.
> 
> I learned how to do all this by looking at the blocks.module.
> This is also the catch. It doesn't work nicely with blocks.module 
> because selecting the current theme is really done through a set of 
> global variables ($theme, $custom_theme). Once one module has overridden 
> $custom_theme, the knowledge about the original theme (user-specific or 
> standard) is lost.
> 
> I currently solve this by excluding admin/block pages from the theme 
> replacement. I have considered to introduce some kind of stack of 
> overridden themes, but as this would affect at least system.module, 
> blocks.module, theme.inc so I wanted to discuss this here first.
> 
> Is anybody working on this theme selection right now?
> This might fall into the realm of Adrian's overhaul of the theming system.
> 
> Cheers,
> Olav
>