How to Customize G2 or Create a module?

Ok, it's only 1 single db query for each request of "overhead" for the syncronization.
Actually you convinced me, it's a far better approach.
Pro:
+ Less modifications in G2
+ All GalleryUsers are GalleryEntities, perfect

kudos get jmullan

I'll add 1 column to GalleryUser and GalleryUserGrouMap Table, 'g_extId'.
All user/group/map data will be stored in the CMS tables, the G2 tables user/group will only contain g_id and g_extId for the CMS <-> G2 user/group mapping.

edit: I'll add the column 'g_id' to the xaraya roles table instead adding a column to the G2 user/group tables, this way I need 1 table join less and the translating the queries gets as easy as it was before without the G2 user table as a 1:1 mapping table.
when migrating from a integrated G2 to a standalone G2, we'll have to extract the user<->group mapping anyway from the CMS, so we'll create a script for this anyway. it shouldn't be an argument to have all G2 user ids in a G2 user table just for the sake of it.

edit: Differentiating between two sets of ids for each user/group, a G2 internal (aka EntityId) and a CMS specific (xar_uid) introduces a major difficulty. The group<->user map is done with the xar_uid and the rest (SELECT, ORDER BY, WHERE = ?, ...) is g_id.
I've extended my Query translator to handle this, hope other CMS can use it too...

here's an example what the translater does:

G2:

SELECT
          [GalleryUserGroupMap::userId],
          [GalleryUser::userName]
        FROM
          [GalleryUserGroupMap], [GalleryUser]
        WHERE
          [GalleryUserGroupMap::groupId] = ?
          AND
          [GalleryUserGroupMap::userId] = [GalleryUser::id]
        ORDER BY
          [GalleryUser::userName]

target: 

SELECT u0.g_id, u0.xar_uname
FROM xar_rolemembers, xar_roles as u0, xar_roles as g0
WHERE xar_rolemembers.xar_parentId = g0.xar_uid
AND g0.g_id = ?
AND xar_rolemembers.xar_uid = u0.xar_uid
ORDER BY u0.xar_uname

what do you think?

First of all, it looks like you're making tremendous progres. I like the idea of doing the synchronization the way that you're suggesting. This is pretty much what the PNphpBB2 modules does to integrate PhpBB2 into PostNuke (that's this forum system) and it seems to work well.

As for the GalleryGroup factories issue, I think you understand the concept just fine, it's just that I didn't think things through to this level of detail when I was setting up the factory implementations. The problem is that we're using the class name as the id, which is wrong. We should separate out the fact that you can register an implementation of GalleryEntity for id GalleryGroup with class name XarayaGroup. That'll require reworking the factory code a little bit, but it's the right thing to do.

For now (since we're just trying to hack it so that it works) I think that you should unregister the GalleryEntity->GalleryGroup implementation and register your own GalleryEntity->GalleryGroup but pass in your own class name, eg:

GalleryCoreApi::registerFactoryImplementation('GalleryEntity',
    'GalleryXarayaGroup',
    'GalleryGroup',
    $classDir . 'GalleryXarayaGroup.class');

Hm. As I typed the above, I realize that we actually do separate out the class name and the id and from reviewing the code it seems like this would get put into the factory correctly so that if you asked for a GalleryEntity->GalleryGroup you'd get a XarayaGroup. I'm late for the door (kids are banging on the office door yelling "DAD WE'RE HUNGRY") and Jen is giving me looks so I can't test this out now but this is should work. If it doesn't, we can always hack up the factory (just put in some special case if/then blocks in there) to make it work and let me know and I'll fix it so that it Does the Right Thing.

update:
it works
- in init.php i check with 1 simple query if there are xaraya roles (users/groups) that have not a G2 Entity and if so create Entities for them.
- i get the active user from xaraya
- replaced 3 user group map functions in the UserGroupHelper classes using a mixture of xaraya API and G2 queries
- changed some functions in DatabaseStorage.class and extended the translateQuery
- changed User / Group class and interface. In future I won't have to change them when I can register my own implementations
- added g_id and g_language to xaraya roles table, gonna have to find a solution for g_language as it can't stay there, i think (redundancy etc.)

todo:
- unregister User/group views
- don't display login / your account link
- put css and javascript from G2 to xaraya <head> section
- get G2 page title somewhere
- G2 links[] -> somehow to xaraya menu
- put the whole thing into a module

I wanted to summarize all changes needed to make G2 work within xaraya (not quite all changes, I've not yet started looking into a search xaraya plugin).
Most changes can't be made with a G2 module and are marked as such.

Changes needed:

G2: indicates that the changes cannot be made without changing G2 files
module: part of the xaraya module in G2
module in xaraya: part of the gallery2 module in xaraya

- module in xaraya or main.php: define('G2_MODE_EMBEDDED', 1);
- G2: GalleryUrlGenerator::getCurrentUrlDir(): add function preg_addslashes (non standard function) as xaraya base file contains question marks etc.
function preg_addslashes ($foo)
{
return preg_replace("/([^A-z0-9_-]|[\\\[\]])/", "\\\\\\1", $foo);
} /* credits to the one who posted this function as a comment to php.net */
- G2: GalleryUrlGenerator::buildQueryString() changed: ? -> & because new baseFile already has first argument
- G2: modules/core/classes/GalleryStorage/DatabaseStorage/ErrorHandler.inc
define('ADODB_ERROR_HANDLER') already defined -> if(!defined...
- G2: @adodb GenId problem:
G2 uses the adodb class definitions from xaraya and xaraya has hasGenId set to false.
As a temporary fix I set hasGenId = true in the xaradodb/drivers/adodb-mysql.inc.php in xaraya.
- G2: had to change GalleryUtilities::convertPathToUrl(), the function makes assumptions that don't apply to an embedded G2, i use $_SERVER['DOCUMENT_ROOT'] to fix it. (function neglects difference between gallery base path and xaraya base path)
- G2: getting the whole header in main.php, parsing it in xaraya for title, css and javascript
- G2: unregister core module::getSystemLinks() (login, your account), move language setting to xaraya
had to change getSystemLinks in core module.inc. not including the links based on define('G2_MODE_EMBEDDED', 1); which is set in xaraya
- G2: unregister core module::getSiteAdminViews() (User Group Management)
had to change getSiteAdminViews in core module.inc, btw. typo ("," too much) in original function in return value. not including the links based on define('G2_MODE_EMBEDDED', 1); which is set in xaraya
- G2: in init.php: put some xaraya code to get the current user and all xaraya users/groups that don't have a corresponding G2 entity yet.
- module: created a GalleryXarayaUser and a GalleryXarayaGroup in a G2 module
- G2: DatabaseStorage.class: switching between G2 standalone and embedded mode based on the constant G2_MODE_EMBEDDED. when in embedded mode: translate user/group queries differently and don't create/update/insert/delete data managed by xaraya (user, group, -map tables)
- G2: GalleryFactoryHelper_simple::newInstance() changed (temp fix): if className == Group or User, change it to XarayaGroup/User.
- G2: GalleryUserGroupHelper_medium::fetchUsersForGroup() changed (xaraya roles tree)
- G2: GalleryUserGroupHelper_medium::fetchGroupsForUser() changed (xaraya roles tree)
- G2: GalleryUserGroupHelper_simple::isUserInGroup() changed (xaraya roles tree)

ToDo:
- module: GalleryUser::language, not yet set-able
- G2: need system/item/... links from G2 with urls somewhere, so that i can pass them to xaraya
- module: when activating the xaraya module in G2, copy the entity ID of the default usergroups/anonymous/admin user to xaraya
- G2: create direct DownloadItem links and handle the renderShortCut (problem: the gallery cookie is sufficient to authenticate a user. there's only 1 possibility when it's insufficient: when a xaraya user has logged of (G2 cookie doesn't know that he logged of).
- G2: set global templates: before activating G2 xaraya module use global.tpl, after use global.tpl.local (remove html, head, body tags)
- module in xaraya: define('G2_MODE_EMBEDDED', 1);
- G2: GalleryUrlGenerator: baseFile different before and after activating G2 xaraya module
-> GalleryUrlGenerator should set the basefile according to the current
- G2: main.php different before and after activation of module (print HTML / copy HTML to variable)