Grid Elements

This resembles the "unused elements" of TV and currently is the only way to keep the items editable somehow after changes to the backend structures of pages and/or Gridelements.

I understand this. But by changing the colPos to -2 you also modify the display of items in frontend. And IMO this should not happen just to make the backend more userfriendly. Instead of in gridelements I would expect such feature (which is of course very useful) in core's page module.

In list module these items are currently visible, arent't they? Maybe with "INVALID VALUE" in colPos if you edit the item, but they are still accessible.

All these little features, which changes the backend and even frontend behavior are suboptimal for gridelements, IMO.
For example the drag & drop feature (besides the fact, that it is already migrated to core): If it wouldn't be migrated I would be forced to use gridelements to have drag & drop. Even if I don't need all the other features like grids or inline wizard on pages or Insert as reference link.

This is a big complete pack, which changes the user experience for TYPO3 backend too much. It goes further away from TYPO3 standard. For me gridelements looks like the new TemplaVoila. But in a bad way, because of the way how to handle the all-included-features.

Please don't missunderstand me. I really like gridelements! Very much! But just for creating grids. Not more, not less. I don't want all the other changes. Or if I want them I would like to be able to choose eg. by installing new extensions which provides them.

Hope you get my point ^^

I won't discuss options for upcoming versions on the issue tracker, since this is not related to this issue. We can do some sessions about it at one of the Camps (will be in Bremen and Essen I guess), the CON or the next DEVDAYS.

Back to the issue:
Inheritance should be respected.
Take a look at line 175 ff. of Classes/DataHandler/AfterDatabaseOperations.php
It reacts on backend_layout_next_level changes and modifies subpage content recursively.

Armin Ruediger Vieweg wrote:

I understand this. But by changing the colPos to -2 you also modify the display of items in frontend. And IMO this should not happen just to make the backend more userfriendly. Instead of in gridelements I would expect such feature (which is of course very useful) in core's page module.

Exactly - and the core still does NOT provide such a feature, although backend layouts have been implemented more than 4(!) years ago AND gridelements are showing at least one possible option how to deal with that problem for 3(!) years now. #22903 is pending for almost the same time. Even though it might not be your preferred solution, at least it IS a solution for these problems.

In list module these items are currently visible, arent't they? Maybe with "INVALID VALUE" in colPos if you edit the item, but they are still accessible.

So people will see lots of "invalid values" IF they got access to the list module, or they just see nothing in the page module (for example because they are not allowed to access the list module) making them think they lost their content elements. IMHO Gridelements should deal with these problems at least until there is a proper solution provided by the core.

BTW: Most of the people who are using gridelements are using backend layouts for pages and content directly connected to a certain frontend output. So they definitely WANT to change the frontend output by changing the backend structures.

Take a look at line 175 ff. of Classes/DataHandler/AfterDatabaseOperations.php

$this->getSubpagesRecursively($this->getPageUid(), $subpages);

The problem is this in the getSubpageRecurively:

if ($page['backend_layout'] === 0) {}

if ($page['backend_layout_next_level'] === 0) {}

According to this patch https://review.typo3.org/#/c/25135/ actually none of the backend layout fields should be empty anymore.
If this is still the case, we need to change that in the core.

Still it would not hurt to use empty instead of 0 in Gridelements to be on the safe side.

It seems they broke it again with this one https://review.typo3.org/#/c/24882 and it has not been reverted yet. :-(

Patch set 1 for branch master of project TYPO3CMS/Extensions/gridelements has been pushed to the review server.
It is available at http://review.typo3.org/31771

Well, empty() will fit 0 and '' and NULL, so whatever they do, this is save :)