FEATURE: Custom Route for node preview

[bwaidelich]

Introduces a new Route /neos/preview that will be used for previewing/editing purposes in the content iFrame and to preview content that is not live or visible (yet).

Advantages

Greatly reduced amount of routing cache entries

Previously, URLs for nodes in the backend had the format <the/node/url/path>@<workspace-name>;<dimensions>
Thus leading to two routing cache entries (match & resolve) for each user, node & dimension combination.
With this change, there is only one route for those cases usinq query parameters to specify the node & context: /neos/preview?node=<the/node/url/path>@<workspace-name>;<dimensions>

Explicit preview action

With a custom action just for the preview scenario, we can remove a lot of special magic (like displaying hidden nodes, shortcut handling, ...) from the regular frontend rendering path

Faster backend navigation

Previously all links in the Backend triggered a redirect route, effectively resulting in two requests.

Basis for further improvements and simplifications

With a different route (and action) we could greatly simplify the code of the FrontendRoutePartHandler and make way for new features like partial matching (#780), multi-format-support (#870) dedicated workspace previews, ...

Note: This requires neos/neos-ui#2604 to work as expected

Resolves: #2653

[davidspiola]

Could you pls rebase this PR to the lastest master. The page tree does not work with it in the current state. FYI: the page tree works in the current master

[bwaidelich]

@davidspiola I merged the current master branch into my fork. But for me the backend currently doesn't load with latest master Update: I had frontendDevelopmentMode enabled - can reproduce this now and will take care!

If you test this, make sure to flush caches (also browser caches to remove session cookie) and to apply neos/neos-ui#2545

[bwaidelich]

@davidspiola (and all) can you please test again now? It was the Neos.UI change that needed rebasing. I got confused so I created a new PR against master: neos/neos-ui#2604

[davidspiola]

@davidspiola (and all) can you please test again now? It was the Neos.UI change that needed rebasing. I got confused so I created a new PR against master: neos/neos-ui#2604

will do

[davidspiola]

Strange behavior, but might be totaly unrelated to you PR. If I navigate in the page tree I get 404 errors. Links within the website are working correctly. If I test with current master it work as expected.

[markusguenther]

Works like charm 🎉