I see now that there is a way to do this using elementsBelongTo and belongsTo (ZF-9451).

That would require Zend_Form_SubForm to have a belongsTo member as well, that is not the case atm. What is the way you see it?

I would love to see that. I have a deeply nested set of elements that I finally got to name correctly using the elementsBelongTo property on their immediate subform parent, but that is making for some interesting returns in ::getValues($_POST) since Zend_Form is seeing multiple belongTos and nesting them oddly in the merge - element is getValues is merging the subForms' belongTos on top of array so that I end up with something like:

'items' => 
    array
      'items' => 
        array
          410412232 => 
            array
              30181391 => 
                array
                  'Attendance' => string '' (length=0)
      410412218 => 
        array
          'items' => 
            array
              410412218 => 
                array
                  30181391 => 
                    array
                      'Attendance' => string '1' (length=1)

I was planning to override getValues in my extended form and see if I can get it to drop the extra nesting.
With that in mind, I think adding an option to iterate over all the parents would be great. The idea seems easier than what I'm doing above (elementsBelongTo and overriding the ::getValues() to fix the array). But you know this thing inside and out and know what kind of mess it would make to add that feature.

I thought about what you said about adding a belongsTo member to SubForm and decided to give that a shot since my attempt at overriding ::getValues() above was turning into a bigger mess than it was worth. I can guarantee I've missed some obvious things/bugs/disasters in what I did, but I thought I'd pass it on and if there is anything you can use, have at it! I decided to go with 'parent' as the subForm member and used it to modify the belongsTo properties as needed. It basically grabs the parent of the previous form/subform and adds it to the current subform + the current's parent, a simple array. I extended Zend_Form and Zend_Form_SubForm (only so I could point it at my new Form class so it could pick up the parent property). I made a small change to Zend_Form_Decorator_FormElements::render method as follows:

    /**
     * Render form elements
     *
     * @param  string $content
     * @return string
     */
    public function render($content)
    {
        $form    = $this->getElement();
        if ((!$form instanceof Zend_Form) && (!$form instanceof Zend_Form_DisplayGroup)) {
            return $content;
        }

        $belongsTo      = ($form instanceof Zend_Form) ?
             ( $form->getParentString() !== false ?
               $form->getParentString() :
               $form->getElementsBelongTo() ) :
                    null;

My extended files are attached. Yes I know, "PC" isn't Zend legal ;) I know there will be a lot more to it than what I've done here (like adding the toggle to use all the parents or not for multipage), but I hope it is in the right direction!

PC_Form and PC_Form_SubForm files

Oops, overriding _setElementsBelongTo() causes double nesting. Leaving it as is seems to work perfectly.

Postponing, should have for 2.0

Some updated files (finally got around to extending the Zend_Form_Decorator_FormElements class instead of my little hack to the actual Zend file... laziness and procrastination!). Added a flag to set whether to use the parent form's in the array naming or not (::setUseParent(bool)). If it is set, it will use the parent's names in the array naming scheme. If not, it will use only the item being rendered as the parent.

There is a problem with it rendering parents correctly when rendering an entire form (<?php echo $this->form; ?> versus rendering the elements through a viewscript (<?php echo $this->element->elementname; ?>). The viewscript rendered elements pick up the parents correctly while the rendered form seems to drop the nesting above the form being rendered. I haven't had time to look into it and figure out why since I have been using a viewscript when I need the deep nesting anyway. (more laziness and procrastination)

I thought I would add my 'new' files in case they can help out with building 2.0.

Oops, I guess I can't upload files anymore!