Recursively search into a template node list for PlaceholderNode
    node.

def _placeholders_recursif(nodelist, plist, blist):
    """Recursively search into a template node list for PlaceholderNode
    node."""
    # I needed to do this lazy import to compile the documentation
    from django.template.loader_tags import BlockNode

    for node in nodelist:

        # extends node?
        if hasattr(node, 'parent_name'):
            _placeholders_recursif(node.get_parent(dummy_context).nodelist,
                                                        plist, blist)
        # include node?
        elif hasattr(node, 'template') and hasattr(node.template, 'nodelist'):
            _placeholders_recursif(node.template.nodelist, plist, blist)

        # Is it a placeholder?
        if hasattr(node, 'page') and hasattr(node, 'parsed') and \
                hasattr(node, 'as_varname') and hasattr(node, 'name'):
            already_in_plist = False
            for placeholder in plist:
                if placeholder.name == node.name:
                    already_in_plist = True
            if not already_in_plist:
                if len(blist):
                    node.found_in_block = blist[len(blist) - 1]
                plist.append(node)
            node.render(Context())

        for key in ('nodelist', 'nodelist_true', 'nodelist_false'):
            if isinstance(node, BlockNode):
                # delete placeholders found in a block of the same name
                offset = 0
                _plist = [(i, v) for i, v in enumerate(plist)]
                for index, pl in _plist:
                    if pl.found_in_block and \
                            pl.found_in_block.name == node.name \
                            and pl.found_in_block != node:
                        del plist[index - offset]
                        offset += 1
                blist.append(node)

            if hasattr(node, key):
                try:
                    _placeholders_recursif(getattr(node, key), plist, blist)
                except:
                    pass
            if isinstance(node, BlockNode):
                blist.pop()