UncleCheese,
first of all, great work on the dataobjectmanager! it's wonderuful!

I have checked out the latest version of the nested branch and dataobjectmanager and image_gallery
i can't seem to get the popup to show the formfields needed to add or edit data.
the popup stays empty.
When i use the nestedurls code in dataobjectmanager_nestedurls the whole cms just errors.
Is the nestedurls code up to date? is there a workaround to get things running?

thanks!

No, the nestedurls code is a work in progress. I've been having a hard time getting it to work right. What do you mean the CMS "just errors?"

i get a completely blank page... no error message. i'll do some digging to find what causes it

when i comment out DataObjectManager::allow_assets_override(true);
the admin loads again but the image_gallery shows an empty javascript alert...

edit: my bad - now i get:
js alert:
ERROR [Notice]: Undefined index: DataObjectManager
IN POST /admin/getitem?ID=6&locale=en_US&ajax=1
Line 149 in /Volumes/LaCie/workspace/nested/sapphire/core/ClassInfo.php

Source
======
140: /**
141: * @todo Improve documentation
142: */
143: static function ancestry($class, $onlyWithTables = false) {
144: global $_ALL_CLASSES;
145:
146: if(is_object($class)) $class = $class->class;
147: else if(!is_string($class)) user_error("Bad class value " . var_export($class, true) . " passed to
ClassInfo::ancestry()", E_USER_WARNING);
148:
* 149: $items = $_ALL_CLASSES['parents'][$class];
150: $items[$class] = $class;
151: if($onlyWithTables) foreach($items as $item) {
152: if(!DataObject::has_own_table($item)) unset($items[$item]);
153: }
154: return $items;
155: }

translatable doesn't work probably so i did a clean install
all i'm getting now is a
"there was an error" message on trying to edit the imagegallerypage

next up:
setpluraltitle function didn't exist on the nesturls dataobjectmanager so i added that
now i can edit the imagegallerypage again.
On adding or editing an album or image i get the empty popup again.
now i'm looking at my php log wich mentions:

HP Fatal error: Call to a member function getErrors() on a non-object in /Volumes/LaCie/workspace/nested/sapphire/forms/Form.php on line 543

After patching this bug in the nestedurls branch
http://open.silverstripe.com/ticket/3814

the default dataobjectmanager code with the image_gallery seems to be working fine for a basic install.
only thing is the coverimage doesn't work:

[User Error] Uncaught Exception: Object->__call(): the method 'field' does not exist on 'DataObjectManager_ItemRequest'

and importingalready uploaded images
[User Error] Uncaught Exception: Object->__call(): the method 'backlinktracking' does not exist on 'ImageGalleryImage'

this seems to be consistent errors caused by nested urls