Slow loading on Block Config/Layout Builder pages

Hi,

Thanks for your feedback.

So this happens in 2 areas, Structure > Block Layout and in blocks in Layout Builder?

Does it happens in other places with UI Styles? section config form in Layout Builder, Theme regions with ui_styles_page, etc.

In structure block layout, if you uninstall ui_styles_block, there is no more slow down?

Yes that's right. All those interfaces where UI Styles are loading.

Going from the page to Configure Block took about 6+ seconds. Dropped to 1 after disabling UI Styles Block.

About the same for layout builder blocks and sections forms.

6 seconds is not huge, but when working on building up a page in layout builder using a lot of styles, it can take a lot of extra time.

This is noticeable with a fresh setup.

Strange because, I quickly checked the daisyUI styles and there is like 800 lines. While UI Suite Bootstrap has like 1500 lines and I don't have slowness problem with Bootstrap with CSS aggregation disabled, and cache disabled.

Would it be the CSS file generated on the fly for preview with UI Styles widget/source?

So the problem is that with Daidy UI the styleheet generation ui_styles/stylesheet.css?prefix=.ui-styles-source-select-plugin takes 6 sec.

Checking mine with Bootstrap, it takes 50ms. And Bootstrap has more styles than Daisy UI.

So it highly depends on how those classes are used, how the CSS is organized.

It also made me realize that the controller response is not cached in the browser, and the payload is not optimized (removing empty lines, white space).

So, we need to:
- make the controller response cacheable (even if it should already be the case), if not possible, save the generated file in public stream wrapper.
- optimize the payload.