Review theming capabilities of the frontend and create example for docs

[t-muehlberger]

Add a parameter that allows loading an additional CSS file that allows overriding existing CSS-Variables and Rules.

[jbethune]

Where would this parameter be configured?

[jbethune]

@t-muehlberger Shouldn't this be part of the 4.0 milestone? Or do you have a particular use for this in mind for the chatcontrol campaign?

[socialhack]

It could very well be that some of the CSAR campaigns need or would want this to embed our tool in their websites.

[t-muehlberger]

@jbethune The scope of this task (simply loading one more css file) should be quite simple and quick to implement and might be beneficial for some campaigns, this is why it is part of the earlier milestone.

[t-muehlberger]

During the work on the frontend documentation, I noticed that, while we built the stylesheets with theming in mind, we never really tested the theming capabilities of the client. I think we should try to override some styles and also create an example of how to embed DearMEP with a custom theme.

TODOs:

• Try overriding some CSS Custom Properties in an embedded version of DearMEP
• Add example to documentation

[t-muehlberger]

Thank you, @scy, for removing this issue from the milestone. As we discussed, this feels more like a documentation task and doesn’t need to block the release.

While working on this, I experimented with creating a custom theme for DearMEP and used those insights to enhance the documentation in #309.

The theming experience works for many scenarios, though it could be more streamlined. Specifically, I couldn’t find a way to customize the Angular Material 2 theme solely with CSS custom properties without an SCSS build. While this adds some complexity, the important thing is that customization is possible. I’m hopeful that future updates will improve the process.

Switching to Angular Material 3 might help, as it introduces changes to the theming system that could address some of these limitations. However, this would require further investigation, and it’s worth noting that such a change would also visually alter the appearance of DearMEP.

Alternatively, we could explore creating scripts to simplify the process of building and applying a custom theme using the current approach.

I am still unsure if we want to close this issue now and create a new issue once the need for more advanced theming arises in the future. Or maybe we should keep it open just to keep track of possible enhancemants.