Preview link broken until post is saved for the first time

[hartsook]

Issue Overview

Gutenberg 0.9
Preview link at top of page does not work unless I update the page first. I get a new browser tab -
about:blank. 

Steps to Reproduce (for bugs)

1. Create Gutenberg post
2. add content
3. publish post
4. edit post in Gutenberg
5. make change in post
6. click Preview link at top of page
7. Chrome opens a new tab with about:blank URL
8. This occurs in both author and admin roles
9. If I Update the post first, then the Preview link works.

Expected Behavior

If I make changes in a post I should be able to preview the post before Updating, especially if this is a Published post and not a Draft post.

Preview link should work like it does currently.

Current Behavior

Preview link at top of page does not work unless I update the page first. I get a new browser tab about:blank. 

Possible Solution

Related Issues and/or PRs

Todos

• Tests
• Documentation

[youknowriad]

Duplicate #1773 (comment) ?

[karmatosed]

Despite #1773 being closed, I can still replicate this myself.

[ptasker]

Can also replicate this.

[hedgefield]

I can replicate this too by opening the demo post on my own site and hitting Preview right away. But that is likely related to the core issue I reported earlier, as I cannot (auto)save a post, so the REST API task label is 👌 .

[aduth]

Current status: This was intentionally not implemented because it is not possible yet to support in the REST API.

Related:

• Add Autosave functionality #1773 (comment)
• https://core.trac.wordpress.org/ticket/43316

[danielbachhuber]

Looks like this is still an issue:

Notably, it's a bug because the "Preview" button is broken until the first revision is saved. In my GIF, I write "Foo" in the title and then immediately hit the "Preview" button. The first preview UX is broken. However, by the time I navigate back, the first revision is saved and preview begins working correctly.

[danielbachhuber]

Likely blocked by #6257

[danielbachhuber]

@aduth Can you summarize the underlying issue here, and what needs to be done to address it?

[aduth]

@danielbachhuber See also #7179.

Basically, to be able to complete the redirect, we need a preview link. This is made available for a full save on the post endpoint's preview_link property. We don't have this yet for published posts autosave (#7179).

In parallel, the PostPreviewButton component should be refactored to rely less on the save process specifically, and merely the presence of this link. I'm working on this currently. Then, once the preview link is added for autosaves (returned by getEditedPostPreviewLink), it should "just work".

[aduth]

Closed by #7130.