Take over the Preview button

Realized that this was close enough to an ajax based concept that I had been working on, so opened an MR.

Hoping this can be useful to think about what same page behavior would look like, even as we figure out layout. Same page behavior only works on edit forms. Node add still uses the traditional preview.

Attached a vide demo.

I see that once the page has been created then we can take over the preview button. This meets the minimum of what we're shooting for. I'll review this soon.

When testing this I frequently got this error:

https://git.drupalcode.org/project/same_page_preview/-/merge_requests/3 is the combination of your work, and my tweaks.

@cosmicdreams took a look at your changes. All looked good to me, so I've integrated it into the existing MR branch here.

I'm going to continue on, trying to make this work on the node add page as well.

did you say you have more commits incoming for this issue?

When you say you're going to continue on, do you mean in this issue? We could close this issue with the MR you've got here. Then we can continue in a new issue with whatever is left.

I'm going to break out a follow up issue to take on the rest. Let's get this work in and move on.

Progress:
Clicking the preview button will update the in-page preview instead of launching a new page.

Next Steps:
📌 Provide a button to open preview in new page Active