BUG: Nesting elements that have database relations in flex form sections is not allowed.

[oooFreaKooo]

Versions

• DCE version: 3.3
• TYPO3 version: 13.4
• PHP version: 8.4

Describe the bug

I was adding some Elements with the DCE Module and now my entire backend is unreachable.
This is the Error im getting:

(1/1) #1458745468 UnexpectedValueException
Invalid flex form data structure on field name "image" with element "settings.icons" in section container "container_icons": Nesting elements that have database relations in flex form sections is not allowed.

How can i recover my Project? Is there a way to undo the changes?
Why does it kill my entire backend instead of jsut throwing a silent error? Please help

EDIT:
The weird thing is, placing images into nested sections works on the other typo3 project that uses v12
All im doing is copy over the DCEs.
When merging the databases, i had the same error, so thats the reason i copy them by hand. But why is this working for v12 and not for v13?

[oooFreaKooo]

The only solution was to remove that DCE from the database:

ddev mysql -e "DELETE FROM tx_dce_domain_model_dcefield WHERE parent_dce = 2;"

and then it still couldnt clear the cache. So i had to delete the entire var/cache folder:

ddev exec "rm -rf var/cache/*"

Is this really the only way do undo a mistake? This is really horrible...
If there is a better way of fixing a minor mistake in the DCE module, please let me know.

[a-r-m-i-n]

Hi @oooFreaKooo, I'm sorry that your upgrade experience was horrible. I can understand your frustration.

Let me explain why that happened: The core of TYPO3 refactoted the Flexform handling and it is more strict now, why they've added this exception.

I'm not sure what kind of field configuration you've actually tried to use, but apparently it is not supported by TYPO3 anymore.

Maybe you could provide the section field config in this issue, so I can update DCE to not save this malfunction generated TCA code and avoid this exception blocking the whole installation.

Unfortunately what you tried to achieve will not work anymore in TYPO3 v13. But I can help to avoid this blocking exception.

Cheers, Armin

[oooFreaKooo]

Hi @a-r-m-i-n thanks for the response.

What im trying to do is a basic timeline Element with a title, subtitle and a section field. The section field has a year, text and an image.

This works fine in v12 and on v13 this kills the entire backend as mentioned.
Im new to this extension because i usually use Contentblocks, but this is a different project from a client.
Are there alternative approaches? To enable the CMS users to create multiple items with images?

[oooFreaKooo]

Ok now something strange happens.
I wanted to try it out again so Ive deleted all the dependencies from my extension, and as soon as i install dce v3.3.0 im getting this and the entire backend breaks again.

Very weird

[a-r-m-i-n]

It seems, that there is some invalid XML / FlexForm code somewhere, which cause this warning. This is just a warning, when you exclude warnings from exception handler, this issue at least won't break your installation.

[a-r-m-i-n]

You are lucky, that you have the requirement just at the moment. DCE itself has a feature called DCE container, but it is not a real container, it just simulates it.

But today I've published a new TYPO3 extension called "vici", which allows you to create new database tables right from the backend. Currently DCE is not supporting it, but I want to implement this feature soon (probably next week) - so you could create a timeline table and use an inline field in DCE to use them.

You'll find the vici extension here: https://github.com/a-r-m-i-n/vici
On packagist it got the key t3/vici.

Because some stuff like documentation is still missing, it is not released in TER yet.

If you want, I keep you up2date.

[oliverschloebe]

Having the same issue. Is there an upgrade wizard available or any idea on how to do a proper migration?

[a-r-m-i-n]

@oliverschloebe There is no upgrade wizard existing, also it is not possible to write one. TYPO3 core does not allow to use relations inside Flexform sections anymore.

What I can do is to avoid the exceptions, blocking the whole TYPO3 installation. To achieve this, section field configs containing relations, will not get written to cached TCA code anymore. That also means, that those fields won't appear anymore, in the backend.

The only possibility to keep the previous functionality is to use an inline field, instead of using sections. Unfortunately DCE isn't capable to create own tables. For this you need to create own TCA in an extension, until now.

With the new VICI extension, you can create own table structures in the backend, but it is still in early development and not finally released yet. Please stay tuned, I will work on this in the next few weeks and then there will be an alternative to replace the section fields properly. For a preview you can checkout https://github.com/a-r-m-i-n/vici if you want.

[oooFreaKooo]

@a-r-m-i-n HI
The "undefined array key el" started happening when I created a tab element with DCE and saved.
The entire Backend was blocked as usual, so i deleten everything DCE related from the database. Didnt help.
The weird thing is, every time i install the extension again, this error pops up. So sadly the DCE extension is unusable for me at the moment.
Since im on a tight time schedule, i simply converted the DCE elements into Contentblocks. Now everything works perfectly.

For the vici topic:
This extension looks interesting, i will have a look. Anything that can be done directly from the CMS is a big plus for me as i see it.

I did actually build some extensions myself aswell, but non of them is "realeased" yet, since im new to Typo3 and didnt look into it yet.
Ive built a "AI Contentblock Generator". You can chat with the AI directly in the CMS and tell it what the element should be like and it generates it for you. There is a preview section and ability to adjust the yaml file (for people with coding experience). If no coding experience and you need to modify the Contentblock, you can simply give the AI follow-up messages. If it generates nonsence and the validation fails, you can simply copy the error code to the chat and it fixes it.
If you want to collaborate and do a release with me, let me know. I dont have much backend experience, so i basically vibe-coded the entire thing.

[a-r-m-i-n]

I was able to add the EXT:vici support to DCE. It is not documented yet, but it works :)

What you need to do:

1. Get and install t3/vici and t3/dce in dev-master versions:

   composer req t3/dce:"dev-master" t3/vici:"dev-master"
   

2. Make sure the database schema updates got applied (in Database Compare tool)
3. Go to list view and create a new VICI table
   • it is important that "Ignore page type restriction" (in tab "Visbility") is enabled
   • optionally you could also check "Hide table", if you want those records only to be created via an inline field in a DCE
4. Go to the VICI backend module, clear the system caches and perform Database compare
5. Create or edit a DCE and add a new field with this configuration:

   <config>
       <type>inline</type>
       <foreign_table>tx_vici_custom_NAME</foreign_table>
       <dce_load_schema>1</dce_load_schema>
   </config>
   

   Replace "NAME" with the name you defined in the new VICI table.

That's it.

Now you can create as many records in your DCE as you like (including images):

And in DCE template you get an array of Extbase proxy models (which has been generated by VICI), including resolved file reference, which you can directly use in an image view helper:

[w010]

I can't update any DCE based project to v13, all I got even in install tool is:

#1458745468 UnexpectedValueException
Invalid flex form data structure on field name "seite" with element "settings.quicklinks" in section container "container_quicklinks": Nesting elements that have database relations in flex form sections is not allowed.

But probably most of these custom contents were somehow nested, that's why DCE was used back then.

The example config of the DCE from the error message looks like this:

So if that's not supported anymore, and I can't see any migration wizards, and that worked perfectly well since version 9 or 10, then what options do I have now? I have no idea how to proceed, what can I do now? What it exactly wants from me? It's very hard to find any meaningful details about that exception

[a-r-m-i-n]

@w010 This exception is a restriction the core made. Unfortunately I'm unable to help here.

You need to reimplement the section based DCEs which are using relations. There are several possibilities, the easiest one would be using the DCE container feature.