Implement auto-save of the page template config entity

📌 Add setting to enable XB for page templates Active is in!

This has 📌 Add support for global regions Active merged in and will make more sense once that has landed in 0.x.

At present autosave and reload of page templates seems to work, next steps is to actually render the autosaved page template, plus the saved model needs adjusting to extract only the parts relevant to the content entity and page template entity instead of saving the entire thing.

📌 Add support for global regions Active is in!

Rebased following 📌 Add support for global regions Active being merged.

I've tied this in with 📌 Add setting to enable XB for page templates Active and ensured that:

• If the page template is enabled, we send all regions to the layout and preview endpoints
• If the page template is disabled or doesn't exist, we only send the content region

#10++ — nice! 😄

Many questions on the MR, but this is definitely going in the right direction! 👍

Assigning to @longwave because he's actively working on it, and Lee is hopefully asleep 😊

Assigning to Wim for review, I've reviewed this and think that we are in good shape with it, and can't see anything left to do except @todos that are already tagged.

I do think that we could try and remove the root UUID now as it's a bit meaningless, we do special steps to ensure it exists, but why does it have to exist at all? Opened 📌 Remove root UUID Active to investigate that.

This looks fantastic, but an E2E test is now failing. Possibly due to a recent commit to 0.x?

I might be wrong, but I think Wim is off work this whole week for the holidays, so I reviewed this in his stead, and it looks great to me, so I merged it. @wim leers: I hope I didn't miss anything important that you would have caught.

@effulgentsia This MR had many more commits after my December 19 review than before. This is one of the bigger MRs merged into XB! So to remain on top of this project, I had to review it in its entirety, to understand all changes.

Here's a screen recording that was shared in community slack during a recent meeting.

I'll add a follow up for the spacing

Added 🐛 If an autosave entry exists before enabling global regions for a theme, theme regions cannot be seen Active which I experienced whilst getting screenshots for the spacing follow up. Perhaps that explains the issue you saw in manual testing Wim?

Opened 🐛 Empty global regions add unnecessary spacing to preview Active for the whitespace - its coming from CSS in Olivero targetting the .region class

#19: yes, 🐛 If an autosave entry exists before enabling global regions for a theme, theme regions cannot be seen Active sounds like a highly probable explanation! Thanks for 🐛 Empty global regions add unnecessary spacing to preview Active , too. Bumped both to .

This allowed me to update #3455753 in a detailed way for the status of the 19. Modify the page template deliverable: #3455753-32: Milestone 0.3.0: Early preview → .