Use the index of the last child of a collection to construct the element's form

[delyriand]

Q	A
Branch?	1.8
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Related tickets	-
License	MIT

When we have a CollectionType with children that have a numerical index, the "add" button can have a strange behaviour when deleting elements and adding new items.
For example, we have an array of items like this:

• 1 => [...]
• 3 => [...]
• 4 => [...]
• 5 => [...]

Previously, the JS code count the number of items, so 4, and add a new form with inputs name my_beautiful_collection[items][4][XXXX]. And when we submit the form, my "4" item is replace by the new "4"…

Like explained in Symfony doc, I use the last collection item to calculate the index of the new element: https://symfony.com/doc/5.4/form/form_collections.html#allowing-new-tags-with-the-prototype

This patch should be applied on all still maintained branches: 1.9, 1.10, 1.11 and master

[AdamKasp]

hello, @delyriand I am not able to reproduce it, can you provide more detailed descriptions (maybe some screenshots?)
any tests also will be appreciated :)

[maximehuran]

Hi, we have the case with the https://github.com/monsieurbiz/SyliusRichEditorPlugin/
When we have collection elements, sometimes some data is removed due to the incorrect index.

I have also other issues with this javascript I think I will try to correct it.

Example :

I have a collection in a collection

The second element of the second collection is split in the first collection :

If I correct the form after the first sumbit, it seems to be ok.

[maximehuran]

It seems the post data are not correct :

And the second time when it's ok :

I search a little and found it's a configuration to add in my form :

            ->add('openings', CollectionType::class, [
                'entry_type' => OpeningType::class,
                'prototype_name' => '__opening__',
                'label' => false,

I added prototype_name in all my collection forms to have __name__ by default this will cause issue while replace.
So there is no issue with the embed collection in Sylius' javascript.

Put this pull request still important to avoid problems with the elements numerotation.

[jacquesbh]

We've got an issue with this PR when we edit an attribute: An exception has been thrown during the rendering of a template ("Warning: A non-numeric value encountered"). in vendor/sylius/sylius/src/Sylius/Bundle/UiBundle/Resources/views/Form/theme.html.twig:90

The issue is because form.children|last.vars.name has a non numeric valud (45fee6f4-1e37-11ed-8248-827b9ec727bb).

A change could be:

+               {% if form.children|last.vars.name matches '/^\\d+$/' %}
                 data-index='{{ form.children|length > 0 ? form.children|last.vars.name + 1 : 0 }}'
+               {% endif %}

but I don't know if it keep fixing your own issue :/

[maximehuran]

Hi @AdamKasp

We have this issue in form collections in AJAX, like in Rich Editor Plugin.
For now, we apply the patch on our projects but some people have the same issue and they would like to have the fix in Sylius directly.

• Fix array keys of an element type collection monsieurbiz/SyliusRichEditorPlugin#192
• ImageCollection images no longer array when delete element other than last monsieurbiz/SyliusRichEditorPlugin#220

[maximehuran]

Hi @GSadee can you have a look to this PR ?