Joomla 3.6 nested subforms not saving

Question

I am trying to use the new subform feature to implement nested forms. This greatly increases the readability for developers and I thought it was already possible to do but after testing I am not so sure anymore. So I tried it out and see that while the nested forms are displayed the values are not saved. Here are the codes that are related.

mod_something.xml (repeatable)

            <field name="levelone" type="subform"
              formsource="/modules/mod_something/models/forms/levelone.xml"
              min="1"
              max="9999999999"
              multiple="true"
              layout="joomla.form.field.subform.repeatable"
              groupByFieldset="false"
              buttons=""
              label="Level 1"
              description="" />

levelone.xml

            <field name="leveltwo" type="subform"
              formsource="/modules/mod_something/models/forms/leveltwo.xml"
              min="1"
              max="9999999999"
              multiple="false"
              layout="joomla.form.field.subform.default"
              groupByFieldset="false"
              buttons=""
              label="Level 2"
              description="" />

leveltwo.xml

            <?xml version="1.0" encoding="UTF-8"?>
            <form>
                <field
                    name="test"
                    type="text"
                    default=""
                    label="Test"
                    size="10"
                />
            </form>

Now this seems a bit strange but this is merely build for the purpose of creating a future template to use.

So as I said the field name test shows up nicely but it does not save the input. When I move this field to the levelone.xml (so one level higher) then it does save.

Hopefully anyone knows how to make it save.

Thanks to everyone for helping!

Answer 1

So far this is not yet possible to do in Joomla. Nested subforms or in other words multi level subforms is on the agenda. It's just hoping a good volunteer is ready to tacke this issue.

More info can be found here: https://github.com/joomla/joomla-cms/issues/11551

In the meanwhile the only possible solution is to add your own javascript and copy the values from every input/select field that you added into the deep levels and make them save on the base level. While in theory this would work in reality it will be a absolute hell to manage.