Merge branch 'master' of git://gitorious.org/owncloud/owncloud into oracle-support

Conflicts:
	3rdparty/Sabre/CardDAV/Plugin.php
	3rdparty/smb4php/smb.php
	apps/bookmarks/ajax/addBookmark.php
	apps/bookmarks/ajax/editBookmark.php
	apps/bookmarks/appinfo/migrate.php
	apps/calendar/ajax/calendar/edit.form.php
	apps/calendar/ajax/changeview.php
	apps/calendar/ajax/import/import.php
	apps/calendar/ajax/settings/guesstimezone.php
	apps/calendar/ajax/settings/setfirstday.php
	apps/calendar/ajax/settings/settimeformat.php
	apps/calendar/ajax/share/changepermission.php
	apps/calendar/ajax/share/share.php
	apps/calendar/ajax/share/unshare.php
	apps/calendar/appinfo/app.php
	apps/calendar/appinfo/remote.php
	apps/calendar/appinfo/update.php
	apps/calendar/appinfo/version
	apps/calendar/js/calendar.js
	apps/calendar/l10n/da.php
	apps/calendar/l10n/de.php
	apps/calendar/l10n/fi_FI.php
	apps/calendar/l10n/gl.php
	apps/calendar/l10n/he.php
	apps/calendar/l10n/hr.php
	apps/calendar/l10n/ja_JP.php
	apps/calendar/l10n/lb.php
	apps/calendar/l10n/lt_LT.php
	apps/calendar/l10n/nb_NO.php
	apps/calendar/l10n/pl.php
	apps/calendar/l10n/pt_PT.php
	apps/calendar/l10n/ro.php
	apps/calendar/l10n/ru.php
	apps/calendar/l10n/sv.php
	apps/calendar/l10n/zh_CN.php
	apps/calendar/l10n/zh_TW.php
	apps/calendar/lib/app.php
	apps/calendar/lib/calendar.php
	apps/calendar/lib/object.php
	apps/calendar/lib/share.php
	apps/calendar/templates/part.choosecalendar.rowfields.php
	apps/calendar/templates/part.import.php
	apps/calendar/templates/settings.php
	apps/contacts/ajax/activation.php
	apps/contacts/ajax/addressbook/delete.php
	apps/contacts/ajax/contact/add.php
	apps/contacts/ajax/contact/addproperty.php
	apps/contacts/ajax/contact/delete.php
	apps/contacts/ajax/contact/deleteproperty.php
	apps/contacts/ajax/contact/saveproperty.php
	apps/contacts/ajax/createaddressbook.php
	apps/contacts/ajax/cropphoto.php
	apps/contacts/ajax/currentphoto.php
	apps/contacts/ajax/importaddressbook.php
	apps/contacts/ajax/oc_photo.php
	apps/contacts/ajax/savecrop.php
	apps/contacts/ajax/selectaddressbook.php
	apps/contacts/ajax/updateaddressbook.php
	apps/contacts/ajax/uploadimport.php
	apps/contacts/ajax/uploadphoto.php
	apps/contacts/appinfo/migrate.php
	apps/contacts/appinfo/remote.php
	apps/contacts/css/contacts.css
	apps/contacts/import.php
	apps/contacts/index.php
	apps/contacts/js/contacts.js
	apps/contacts/l10n/ca.php
	apps/contacts/l10n/cs_CZ.php
	apps/contacts/l10n/da.php
	apps/contacts/l10n/de.php
	apps/contacts/l10n/el.php
	apps/contacts/l10n/eo.php
	apps/contacts/l10n/es.php
	apps/contacts/l10n/et_EE.php
	apps/contacts/l10n/eu.php
	apps/contacts/l10n/fa.php
	apps/contacts/l10n/fi_FI.php
	apps/contacts/l10n/fr.php
	apps/contacts/l10n/he.php
	apps/contacts/l10n/hr.php
	apps/contacts/l10n/hu_HU.php
	apps/contacts/l10n/ia.php
	apps/contacts/l10n/it.php
	apps/contacts/l10n/ja_JP.php
	apps/contacts/l10n/ko.php
	apps/contacts/l10n/lb.php
	apps/contacts/l10n/mk.php
	apps/contacts/l10n/nb_NO.php
	apps/contacts/l10n/nl.php
	apps/contacts/l10n/pl.php
	apps/contacts/l10n/pt_BR.php
	apps/contacts/l10n/pt_PT.php
	apps/contacts/l10n/ro.php
	apps/contacts/l10n/ru.php
	apps/contacts/l10n/sk_SK.php
	apps/contacts/l10n/sl.php
	apps/contacts/l10n/sv.php
	apps/contacts/l10n/th_TH.php
	apps/contacts/l10n/tr.php
	apps/contacts/l10n/zh_CN.php
	apps/contacts/l10n/zh_TW.php
	apps/contacts/lib/addressbook.php
	apps/contacts/lib/hooks.php
	apps/contacts/lib/vcard.php
	apps/contacts/photo.php
	apps/contacts/templates/part.contact.php
	apps/contacts/templates/part.contacts.php
	apps/contacts/templates/part.cropphoto.php
	apps/contacts/templates/part.importaddressbook.php
	apps/contacts/templates/part.selectaddressbook.php
	apps/contacts/thumbnail.php
	apps/files/ajax/download.php
	apps/files/ajax/newfile.php
	apps/files/ajax/timezone.php
	apps/files/appinfo/update.php
	apps/files/appinfo/version
	apps/files/index.php
	apps/files/js/fileactions.js
	apps/files/js/filelist.js
	apps/files/js/files.js
	apps/files/l10n/ar.php
	apps/files/l10n/bg_BG.php
	apps/files/l10n/ca.php
	apps/files/l10n/cs_CZ.php
	apps/files/l10n/da.php
	apps/files/l10n/de.php
	apps/files/l10n/el.php
	apps/files/l10n/eo.php
	apps/files/l10n/es.php
	apps/files/l10n/et_EE.php
	apps/files/l10n/eu.php
	apps/files/l10n/fa.php
	apps/files/l10n/fi_FI.php
	apps/files/l10n/fr.php
	apps/files/l10n/gl.php
	apps/files/l10n/he.php
	apps/files/l10n/hr.php
	apps/files/l10n/hu_HU.php
	apps/files/l10n/ia.php
	apps/files/l10n/id.php
	apps/files/l10n/it.php
	apps/files/l10n/ja_JP.php
	apps/files/l10n/ko.php
	apps/files/l10n/lb.php
	apps/files/l10n/lt_LT.php
	apps/files/l10n/mk.php
	apps/files/l10n/ms_MY.php
	apps/files/l10n/nb_NO.php
	apps/files/l10n/nl.php
	apps/files/l10n/nn_NO.php
	apps/files/l10n/pl.php
	apps/files/l10n/pt_BR.php
	apps/files/l10n/pt_PT.php
	apps/files/l10n/ro.php
	apps/files/l10n/ru.php
	apps/files/l10n/sk_SK.php
	apps/files/l10n/sl.php
	apps/files/l10n/sr.php
	apps/files/l10n/sr@latin.php
	apps/files/l10n/sv.php
	apps/files/l10n/th_TH.php
	apps/files/l10n/tr.php
	apps/files/l10n/uk.php
	apps/files/l10n/zh_CN.php
	apps/files/l10n/zh_TW.php
	apps/files_archive/js/archive.js
	apps/files_encryption/lib/cryptstream.php
	apps/files_encryption/lib/proxy.php
	apps/files_encryption/tests/proxy.php
	apps/files_external/appinfo/app.php
	apps/files_external/lib/smb.php
	apps/files_external/lib/streamwrapper.php
	apps/files_external/tests/config.php
	apps/files_external/tests/smb.php
	apps/files_sharing/ajax/email.php
	apps/files_sharing/ajax/getitem.php
	apps/files_sharing/ajax/setpermissions.php
	apps/files_sharing/ajax/share.php
	apps/files_sharing/ajax/toggleresharing.php
	apps/files_sharing/ajax/unshare.php
	apps/files_sharing/ajax/userautocomplete.php
	apps/files_sharing/js/settings.js
	apps/files_sharing/js/share.js
	apps/files_sharing/lib_share.php
	apps/files_sharing/settings.php
	apps/files_sharing/sharedstorage.php
	apps/files_sharing/templates/settings.php
	apps/files_versions/ajax/rollbackVersion.php
	apps/files_versions/versions.php
	apps/gallery/ajax/thumbnail.php
	apps/gallery/appinfo/app.php
	apps/gallery/appinfo/update.php
	apps/gallery/appinfo/version
	apps/gallery/css/styles.css
	apps/gallery/index.php
	apps/gallery/js/pictures.js
	apps/gallery/l10n/ca.php
	apps/gallery/l10n/cs_CZ.php
	apps/gallery/l10n/de.php
	apps/gallery/l10n/el.php
	apps/gallery/l10n/es.php
	apps/gallery/l10n/fi_FI.php
	apps/gallery/l10n/fr.php
	apps/gallery/l10n/it.php
	apps/gallery/l10n/pl.php
	apps/gallery/l10n/pt_PT.php
	apps/gallery/l10n/ru.php
	apps/gallery/l10n/sl.php
	apps/gallery/l10n/sv.php
	apps/gallery/l10n/th_TH.php
	apps/gallery/l10n/tr.php
	apps/gallery/l10n/zh_CN.php
	apps/gallery/lib/album.php
	apps/gallery/lib/hooks_handlers.php
	apps/gallery/lib/managers.php
	apps/gallery/lib/photo.php
	apps/gallery/lib/tiles.php
	apps/gallery/lib/tiles_test.php
	apps/gallery/templates/index.php
	apps/media/lib_ampache.php
	apps/media/lib_collection.php
	apps/media/lib_media.php
	apps/remoteStorage/lib_remoteStorage.php
	apps/tasks/ajax/addtaskform.php
	apps/tasks/ajax/edittask.php
	apps/user_ldap/appinfo/update.php
	apps/user_ldap/group_ldap.php
	apps/user_ldap/lib_ldap.php
	apps/user_ldap/settings.php
	apps/user_ldap/templates/settings.php
	apps/user_ldap/user_ldap.php
	apps/user_migrate/appinfo/app.php
	apps/user_migrate/templates/settings.php
	apps/user_webfinger/host-meta.php
	config/config.sample.php
	core/js/js.js
	core/l10n/da.php
	core/l10n/de.php
	core/l10n/fi_FI.php
	core/l10n/gl.php
	core/l10n/he.php
	core/l10n/hr.php
	core/l10n/id.php
	core/l10n/ja_JP.php
	core/l10n/lb.php
	core/l10n/lt_LT.php
	core/l10n/nb_NO.php
	core/l10n/pl.php
	core/l10n/pt_PT.php
	core/l10n/ro.php
	core/l10n/ru.php
	core/l10n/sv.php
	core/lostpassword/index.php
	core/templates/layout.user.php
	core/templates/login.php
	db_structure.xml
	index.php
	l10n/af/calendar.po
	l10n/af/contacts.po
	l10n/af/core.po
	l10n/af/files.po
	l10n/af/settings.po
	l10n/ar/calendar.po
	l10n/ar/contacts.po
	l10n/ar/core.po
	l10n/ar/files.po
	l10n/ar/media.po
	l10n/ar/settings.po
	l10n/bg_BG/calendar.po
	l10n/bg_BG/contacts.po
	l10n/bg_BG/core.po
	l10n/bg_BG/files.po
	l10n/bg_BG/media.po
	l10n/bg_BG/settings.po
	l10n/ca/calendar.po
	l10n/ca/contacts.po
	l10n/ca/core.po
	l10n/ca/files.po
	l10n/ca/gallery.po
	l10n/ca/settings.po
	l10n/cs_CZ/calendar.po
	l10n/cs_CZ/contacts.po
	l10n/cs_CZ/core.po
	l10n/cs_CZ/files.po
	l10n/cs_CZ/gallery.po
	l10n/cs_CZ/settings.po
	l10n/da/calendar.po
	l10n/da/contacts.po
	l10n/da/core.po
	l10n/da/files.po
	l10n/da/settings.po
	l10n/de/calendar.po
	l10n/de/contacts.po
	l10n/de/core.po
	l10n/de/files.po
	l10n/de/gallery.po
	l10n/de/settings.po
	l10n/el/calendar.po
	l10n/el/contacts.po
	l10n/el/core.po
	l10n/el/files.po
	l10n/el/gallery.po
	l10n/el/settings.po
	l10n/eo/calendar.po
	l10n/eo/contacts.po
	l10n/eo/core.po
	l10n/eo/files.po
	l10n/eo/media.po
	l10n/eo/settings.po
	l10n/es/calendar.po
	l10n/es/contacts.po
	l10n/es/core.po
	l10n/es/files.po
	l10n/es/gallery.po
	l10n/es/settings.po
	l10n/et_EE/calendar.po
	l10n/et_EE/contacts.po
	l10n/et_EE/core.po
	l10n/et_EE/files.po
	l10n/et_EE/settings.po
	l10n/eu/calendar.po
	l10n/eu/contacts.po
	l10n/eu/core.po
	l10n/eu/files.po
	l10n/eu/settings.po
	l10n/fa/calendar.po
	l10n/fa/contacts.po
	l10n/fa/core.po
	l10n/fa/files.po
	l10n/fa/settings.po
	l10n/fi_FI/calendar.po
	l10n/fi_FI/contacts.po
	l10n/fi_FI/core.po
	l10n/fi_FI/files.po
	l10n/fi_FI/gallery.po
	l10n/fi_FI/settings.po
	l10n/fr/calendar.po
	l10n/fr/contacts.po
	l10n/fr/core.po
	l10n/fr/files.po
	l10n/fr/gallery.po
	l10n/fr/media.po
	l10n/fr/settings.po
	l10n/gl/calendar.po
	l10n/gl/contacts.po
	l10n/gl/core.po
	l10n/gl/files.po
	l10n/gl/settings.po
	l10n/he/calendar.po
	l10n/he/contacts.po
	l10n/he/core.po
	l10n/he/files.po
	l10n/he/settings.po
	l10n/hr/calendar.po
	l10n/hr/contacts.po
	l10n/hr/core.po
	l10n/hr/files.po
	l10n/hr/settings.po
	l10n/hu_HU/calendar.po
	l10n/hu_HU/contacts.po
	l10n/hu_HU/core.po
	l10n/hu_HU/files.po
	l10n/hu_HU/settings.po
	l10n/hy/calendar.po
	l10n/hy/contacts.po
	l10n/hy/core.po
	l10n/hy/files.po
	l10n/hy/settings.po
	l10n/ia/calendar.po
	l10n/ia/contacts.po
	l10n/ia/core.po
	l10n/ia/files.po
	l10n/ia/settings.po
	l10n/id/calendar.po
	l10n/id/contacts.po
	l10n/id/core.po
	l10n/id/files.po
	l10n/id/settings.po
	l10n/it/calendar.po
	l10n/it/contacts.po
	l10n/it/core.po
	l10n/it/files.po
	l10n/it/gallery.po
	l10n/it/settings.po
	l10n/ja_JP/calendar.po
	l10n/ja_JP/contacts.po
	l10n/ja_JP/core.po
	l10n/ja_JP/files.po
	l10n/ja_JP/settings.po
	l10n/ko/calendar.po
	l10n/ko/contacts.po
	l10n/ko/core.po
	l10n/ko/files.po
	l10n/ko/settings.po
	l10n/lb/calendar.po
	l10n/lb/contacts.po
	l10n/lb/core.po
	l10n/lb/files.po
	l10n/lb/settings.po
	l10n/lt_LT/calendar.po
	l10n/lt_LT/contacts.po
	l10n/lt_LT/core.po
	l10n/lt_LT/files.po
	l10n/lt_LT/settings.po
	l10n/mk/calendar.po
	l10n/mk/contacts.po
	l10n/mk/core.po
	l10n/mk/files.po
	l10n/mk/settings.po
	l10n/ms_MY/calendar.po
	l10n/ms_MY/contacts.po
	l10n/ms_MY/core.po
	l10n/ms_MY/files.po
	l10n/ms_MY/settings.po
	l10n/nb_NO/calendar.po
	l10n/nb_NO/contacts.po
	l10n/nb_NO/core.po
	l10n/nb_NO/files.po
	l10n/nb_NO/settings.po
	l10n/nl/calendar.po
	l10n/nl/contacts.po
	l10n/nl/core.po
	l10n/nl/files.po
	l10n/nl/settings.po
	l10n/nn_NO/calendar.po
	l10n/nn_NO/contacts.po
	l10n/nn_NO/core.po
	l10n/nn_NO/files.po
	l10n/nn_NO/settings.po
	l10n/pl/calendar.po
	l10n/pl/contacts.po
	l10n/pl/core.po
	l10n/pl/files.po
	l10n/pl/gallery.po
	l10n/pl/settings.po
	l10n/pt_BR/calendar.po
	l10n/pt_BR/contacts.po
	l10n/pt_BR/core.po
	l10n/pt_BR/files.po
	l10n/pt_BR/settings.po
	l10n/pt_PT/calendar.po
	l10n/pt_PT/contacts.po
	l10n/pt_PT/core.po
	l10n/pt_PT/files.po
	l10n/pt_PT/gallery.po
	l10n/pt_PT/settings.po
	l10n/ro/calendar.po
	l10n/ro/contacts.po
	l10n/ro/core.po
	l10n/ro/files.po
	l10n/ro/settings.po
	l10n/ru/calendar.po
	l10n/ru/contacts.po
	l10n/ru/core.po
	l10n/ru/files.po
	l10n/ru/gallery.po
	l10n/ru/settings.po
	l10n/sk_SK/calendar.po
	l10n/sk_SK/contacts.po
	l10n/sk_SK/core.po
	l10n/sk_SK/files.po
	l10n/sk_SK/settings.po
	l10n/sl/calendar.po
	l10n/sl/contacts.po
	l10n/sl/core.po
	l10n/sl/files.po
	l10n/sl/gallery.po
	l10n/sl/settings.po
	l10n/sr/calendar.po
	l10n/sr/contacts.po
	l10n/sr/core.po
	l10n/sr/files.po
	l10n/sr/settings.po
	l10n/sr@latin/calendar.po
	l10n/sr@latin/contacts.po
	l10n/sr@latin/core.po
	l10n/sr@latin/files.po
	l10n/sr@latin/settings.po
	l10n/sv/calendar.po
	l10n/sv/contacts.po
	l10n/sv/core.po
	l10n/sv/files.po
	l10n/sv/gallery.po
	l10n/sv/media.po
	l10n/sv/settings.po
	l10n/templates/bookmarks.pot
	l10n/templates/calendar.pot
	l10n/templates/contacts.pot
	l10n/templates/core.pot
	l10n/templates/files.pot
	l10n/templates/gallery.pot
	l10n/templates/media.pot
	l10n/templates/settings.pot
	l10n/th_TH/calendar.po
	l10n/th_TH/contacts.po
	l10n/th_TH/core.po
	l10n/th_TH/files.po
	l10n/th_TH/gallery.po
	l10n/th_TH/settings.po
	l10n/tr/calendar.po
	l10n/tr/contacts.po
	l10n/tr/core.po
	l10n/tr/files.po
	l10n/tr/gallery.po
	l10n/tr/settings.po
	l10n/uk/calendar.po
	l10n/uk/contacts.po
	l10n/uk/core.po
	l10n/uk/files.po
	l10n/uk/media.po
	l10n/uk/settings.po
	l10n/zh_CN/calendar.po
	l10n/zh_CN/contacts.po
	l10n/zh_CN/core.po
	l10n/zh_CN/files.po
	l10n/zh_CN/gallery.po
	l10n/zh_CN/settings.po
	l10n/zh_TW/calendar.po
	l10n/zh_TW/contacts.po
	l10n/zh_TW/core.po
	l10n/zh_TW/files.po
	l10n/zh_TW/settings.po
	lib/app.php
	lib/base.php
	lib/connector/sabre/file.php
	lib/connector/sabre/locks.php
	lib/connector/sabre/node.php
	lib/db.php
	lib/filecache.php
	lib/fileproxy/quota.php
	lib/files.php
	lib/filestorage/local.php
	lib/filesystemview.php
	lib/group/database.php
	lib/helper.php
	lib/installer.php
	lib/json.php
	lib/l10n.php
	lib/migrate.php
	lib/mimetypes.fixlist.php
	lib/ocs.php
	lib/preferences.php
	lib/public/json.php
	lib/public/util.php
	lib/template.php
	lib/user.php
	lib/user/database.php
	lib/util.php
	lib/vcategories.php
	ocs/providers.php
	settings/admin.php
	settings/ajax/lostpassword.php
	settings/ajax/removeuser.php
	settings/ajax/setbackgroundjobsmode.php
	settings/ajax/setlanguage.php
	settings/ajax/setquota.php
	settings/ajax/togglegroups.php
	settings/apps.php
	settings/css/settings.css
	settings/js/apps.js
	settings/js/users.js
	settings/l10n/bg_BG.php
	settings/l10n/ca.php
	settings/l10n/cs_CZ.php
	settings/l10n/da.php
	settings/l10n/de.php
	settings/l10n/el.php
	settings/l10n/eo.php
	settings/l10n/es.php
	settings/l10n/et_EE.php
	settings/l10n/eu.php
	settings/l10n/fa.php
	settings/l10n/fi_FI.php
	settings/l10n/fr.php
	settings/l10n/gl.php
	settings/l10n/he.php
	settings/l10n/hr.php
	settings/l10n/hu_HU.php
	settings/l10n/it.php
	settings/l10n/ja_JP.php
	settings/l10n/ko.php
	settings/l10n/lt_LT.php
	settings/l10n/mk.php
	settings/l10n/ms_MY.php
	settings/l10n/nb_NO.php
	settings/l10n/nl.php
	settings/l10n/nn_NO.php
	settings/l10n/pl.php
	settings/l10n/pt_BR.php
	settings/l10n/pt_PT.php
	settings/l10n/ru.php
	settings/l10n/sk_SK.php
	settings/l10n/sl.php
	settings/l10n/sv.php
	settings/l10n/th_TH.php
	settings/l10n/tr.php
	settings/l10n/zh_CN.php
	settings/personal.php
	settings/templates/admin.php
	settings/templates/users.php

1 files changed, 1073 insertions, 0 deletions

diff --git a/lib/public/share.php b/lib/public/share.php
new file mode 100644
index 00000000000..6221c75763f
--- /dev/null
+++ b/lib/public/share.php
@@ -0,0 +1,1073 @@
+<?php
+/**
+* ownCloud
+*
+* @author Michael Gapczynski
+* @copyright 2012 Michael Gapczynski mtgap@owncloud.com
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+* License as published by the Free Software Foundation; either
+* version 3 of the License, or any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+*
+* You should have received a copy of the GNU Affero General Public
+* License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+*/
+namespace OCP;
+
+\OC_Hook::connect('OC_User', 'post_deleteUser', 'OCP\Share', 'post_deleteUser');
+\OC_Hook::connect('OC_User', 'post_addToGroup', 'OCP\Share', 'post_addToGroup');
+\OC_Hook::connect('OC_User', 'post_removeFromGroup', 'OCP\Share', 'post_removeFromGroup');
+
+/**
+* This class provides the ability for apps to share their content between users.
+* Apps must create a backend class that implements OCP\Share_Backend and register it with this class.
+*/
+class Share {
+
+	const SHARE_TYPE_USER = 0;
+	const SHARE_TYPE_GROUP = 1;
+	const SHARE_TYPE_PRIVATE_LINK = 3;
+	const SHARE_TYPE_EMAIL = 4;
+	const SHARE_TYPE_CONTACT = 5;
+	const SHARE_TYPE_REMOTE = 6;
+
+	/** CRUDS permissions (Create, Read, Update, Delete, Share) using a bitmask
+	* Construct permissions for share() and setPermissions with Or (|) e.g. Give user read and update permissions: PERMISSION_READ | PERMISSION_UPDATE
+	* Check if permission is granted with And (&) e.g. Check if delete is granted: if ($permissions & PERMISSION_DELETE)
+	* Remove permissions with And (&) and Not (~) e.g. Remove the update permission: $permissions &= ~PERMISSION_UPDATE
+	* Apps are required to handle permissions on their own, this class only stores and manages the permissions of shares
+	*/
+	const PERMISSION_CREATE = 4;
+	const PERMISSION_READ = 1;
+	const PERMISSION_UPDATE = 2;
+	const PERMISSION_DELETE = 8;
+	const PERMISSION_SHARE = 16;
+
+	const FORMAT_NONE = -1;
+	const FORMAT_STATUSES = -2;
+	const FORMAT_SOURCES = -3;
+
+	private static $shareTypeUserAndGroups = -1;
+	private static $shareTypeGroupUserUnique = 2;
+	private static $backends = array();
+	private static $backendTypes = array();
+
+	/**
+	* @brief Register a sharing backend class that implements OCP\Share_Backend for an item type
+	* @param string Item type
+	* @param string Backend class
+	* @param string (optional) Depends on item type
+	* @param array (optional) List of supported file extensions if this item type depends on files
+	* @return Returns true if backend is registered or false if error
+	*/
+	public static function registerBackend($itemType, $class, $collectionOf = null, $supportedFileExtensions = null) {
+		if (!isset(self::$backendTypes[$itemType])) {
+			self::$backendTypes[$itemType] = array('class' => $class, 'collectionOf' => $collectionOf, 'supportedFileExtensions' => $supportedFileExtensions);
+			if(count(self::$backendTypes) === 1) {
+				\OC_Util::addScript('core', 'share');
+				\OC_Util::addStyle('core', 'share');
+			}
+			return true;
+		}
+		\OC_Log::write('OCP\Share', 'Sharing backend '.$class.' not registered, '.self::$backendTypes[$itemType]['class'].' is already registered for '.$itemType, \OC_Log::WARN);
+		return false;
+	}
+
+	/**
+	* @brief Get the items of item type shared with the current user
+	* @param string Item type
+	* @param int Format (optional) Format type must be defined by the backend
+	* @param int Number of items to return (optional) Returns all by default
+	* @return Return depends on format
+	*/
+	public static function getItemsSharedWith($itemType, $format = self::FORMAT_NONE, $parameters = null, $limit = -1, $includeCollections = false) {
+		return self::getItems($itemType, null, self::$shareTypeUserAndGroups, \OC_User::getUser(), null, $format, $parameters, $limit, $includeCollections);
+	}
+
+	/**
+	* @brief Get the item of item type shared with the current user
+	* @param string Item type
+	* @param string Item target
+	* @param int Format (optional) Format type must be defined by the backend
+	* @return Return depends on format
+	*/
+	public static function getItemSharedWith($itemType, $itemTarget, $format = self::FORMAT_NONE, $parameters = null, $includeCollections = false) {
+		return self::getItems($itemType, $itemTarget, self::$shareTypeUserAndGroups, \OC_User::getUser(), null, $format, $parameters, 1, $includeCollections);
+	}
+
+	/**
+	* @brief Get the item of item type shared with the current user by source
+	* @param string Item type
+	* @param string Item source
+	* @param int Format (optional) Format type must be defined by the backend
+	* @return Return depends on format
+	*/
+	public static function getItemSharedWithBySource($itemType, $itemSource, $format = self::FORMAT_NONE, $parameters = null, $includeCollections = false) {
+		return self::getItems($itemType, $itemSource, self::$shareTypeUserAndGroups, \OC_User::getUser(), null, $format, $parameters, 1, $includeCollections, true);
+	}
+
+	/**
+	* @brief Get the shared items of item type owned by the current user
+	* @param string Item type
+	* @param int Format (optional) Format type must be defined by the backend
+	* @param int Number of items to return (optional) Returns all by default
+	* @return Return depends on format
+	*/
+	public static function getItemsShared($itemType, $format = self::FORMAT_NONE, $parameters = null, $limit = -1, $includeCollections = false) {
+		return self::getItems($itemType, null, null, null, \OC_User::getUser(), $format, $parameters, $limit, $includeCollections);
+	}
+
+	/**
+	* @brief Get the shared item of item type owned by the current user
+	* @param string Item type
+	* @param string Item source
+	* @param int Format (optional) Format type must be defined by the backend
+	* @return Return depends on format
+	*/
+	public static function getItemShared($itemType, $itemSource, $format = self::FORMAT_NONE, $parameters = null, $includeCollections = false) {
+		return self::getItems($itemType, $itemSource, null, null, \OC_User::getUser(), $format, $parameters, -1, $includeCollections);
+	}
+
+	/**
+	* @brief Share an item with a user, group, or via private link
+	* @param string Item type
+	* @param string Item source
+	* @param int SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_PRIVATE_LINK
+	* @param string User or group the item is being shared with
+	* @param int CRUDS permissions
+	* @return bool Returns true on success or false on failure
+	*/
+	public static function shareItem($itemType, $itemSource, $shareType, $shareWith, $permissions) {
+		$uidOwner = \OC_User::getUser();
+		// Verify share type and sharing conditions are met
+		if ($shareType === self::SHARE_TYPE_USER) {
+			if ($shareWith == $uidOwner) {
+				$message = 'Sharing '.$itemSource.' failed, because the user '.$shareWith.' is the item owner';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			if (!\OC_User::userExists($shareWith)) {
+				$message = 'Sharing '.$itemSource.' failed, because the user '.$shareWith.' does not exist';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			$inGroup = array_intersect(\OC_Group::getUserGroups($uidOwner), \OC_Group::getUserGroups($shareWith));
+			if (empty($inGroup)) {
+				$message = 'Sharing '.$itemSource.' failed, because the user '.$shareWith.' is not a member of any groups that '.$uidOwner.' is a member of';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			// Check if the item source is already shared with the user, either from the same owner or a different user
+			if ($checkExists = self::getItems($itemType, $itemSource, self::$shareTypeUserAndGroups, $shareWith, null, self::FORMAT_NONE, null, 1, true, true)) {
+				// Only allow the same share to occur again if it is the same owner and is not a user share, this use case is for increasing permissions for a specific user
+				if ($checkExists['uid_owner'] != $uidOwner || $checkExists['share_type'] == $shareType) {
+					$message = 'Sharing '.$itemSource.' failed, because this item is already shared with '.$shareWith;
+					\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+					throw new \Exception($message);
+				}
+			}
+		} else if ($shareType === self::SHARE_TYPE_GROUP) {
+			if (!\OC_Group::groupExists($shareWith)) {
+				$message = 'Sharing '.$itemSource.' failed, because the group '.$shareWith.' does not exist';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			if (!\OC_Group::inGroup($uidOwner, $shareWith)) {
+				$message = 'Sharing '.$itemSource.' failed, because '.$uidOwner.' is not a member of the group '.$shareWith;
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			// Check if the item source is already shared with the group, either from the same owner or a different user
+			// The check for each user in the group is done inside the put() function
+			if ($checkExists = self::getItems($itemType, $itemSource, self::SHARE_TYPE_GROUP, $shareWith, null, self::FORMAT_NONE, null, 1, true, true)) {
+				// Only allow the same share to occur again if it is the same owner and is not a group share, this use case is for increasing permissions for a specific user
+				if ($checkExists['uid_owner'] != $uidOwner || $checkExists['share_type'] == $shareType) {
+					$message = 'Sharing '.$itemSource.' failed, because this item is already shared with '.$shareWith;
+					\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+					throw new \Exception($message);
+				}
+			}
+			// Convert share with into an array with the keys group and users
+			$group = $shareWith;
+			$shareWith = array();
+			$shareWith['group'] = $group;
+			$shareWith['users'] = array_diff(\OC_Group::usersInGroup($group), array($uidOwner));
+		} else if ($shareType === self::SHARE_TYPE_PRIVATE_LINK) {
+				$shareWith = md5(uniqid($itemSource, true));
+				return self::put($itemType, $itemSource, $shareType, $shareWith, $uidOwner, $permissions);
+		} else if ($shareType === self::SHARE_TYPE_CONTACT) {
+			if (!\OC_App::isEnabled('contacts')) {
+				$message = 'Sharing '.$itemSource.' failed, because the contacts app is not enabled';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				return false;
+			}
+			$vcard = \OC_Contacts_App::getContactVCard($shareWith);
+			if (!isset($vcard)) {
+				$message = 'Sharing '.$itemSource.' failed, because the contact does not exist';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			$details = \OC_Contacts_VCard::structureContact($vcard);
+			// TODO Add ownCloud user to contacts vcard
+			if (!isset($details['EMAIL'])) {
+				$message = 'Sharing '.$itemSource.' failed, because no email address is associated with the contact';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			return self::shareItem($itemType, $itemSource, self::SHARE_TYPE_EMAIL, $details['EMAIL'], $permissions);
+		} else {
+			// Future share types need to include their own conditions
+			$message = 'Share type '.$shareType.' is not valid for '.$itemSource;
+			\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+			throw new \Exception($message);
+		}
+		// If the item is a folder, scan through the folder looking for equivalent item types
+		if ($itemType == 'folder') {
+			$parentFolder = self::put('folder', $itemSource, $shareType, $shareWith, $uidOwner, $permissions, true);
+			if ($parentFolder && $files = \OC_Files::getDirectoryContent($itemSource)) {
+				for ($i = 0; $i < count($files); $i++) {
+					$name = substr($files[$i]['name'], strpos($files[$i]['name'], $itemSource) - strlen($itemSource));
+					if ($files[$i]['mimetype'] == 'httpd/unix-directory' && $children = \OC_Files::getDirectoryContent($name, '/')) {
+						// Continue scanning into child folders
+						array_push($files, $children);
+					} else {
+						// Pass on to put() to check if this item should be converted, the item won't be inserted into the database unless it can be converted
+						self::put('file', $name, $shareType, $shareWith, $uidOwner, $permissions, $parentFolder);
+					}
+				}
+				return true;
+			}
+			return false;
+		} else {
+			// Put the item into the database
+			return self::put($itemType, $itemSource, $shareType, $shareWith, $uidOwner, $permissions);
+		}
+	}
+
+	/**
+	* @brief Unshare an item from a user, group, or delete a private link
+	* @param string Item type
+	* @param string Item source
+	* @param int SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_PRIVATE_LINK
+	* @param string User or group the item is being shared with
+	* @return Returns true on success or false on failure
+	*/
+	public static function unshare($itemType, $itemSource, $shareType, $shareWith) {
+		if ($item = self::getItems($itemType, $itemSource, $shareType, $shareWith, \OC_User::getUser(), self::FORMAT_NONE, null, 1)) {
+			self::delete($item['id']);
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	* @brief Unshare an item shared with the current user
+	* @param string Item type
+	* @param string Item target
+	* @return Returns true on success or false on failure
+	*
+	* Unsharing from self is not allowed for items inside collections
+	*
+	*/
+	public static function unshareFromSelf($itemType, $itemTarget) {
+		if ($item = self::getItemSharedWith($itemType, $itemTarget)) {
+			if ((int)$item['share_type'] === self::SHARE_TYPE_GROUP) {
+				// TODO
+			}
+			// Delete
+			return self::delete($item['id'], true);
+		}
+		return false;
+	}
+
+	/**
+	* @brief Set the permissions of an item for a specific user or group
+	* @param string Item type
+	* @param string Item source
+	* @param int SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_PRIVATE_LINK
+	* @param string User or group the item is being shared with
+	* @param int CRUDS permissions
+	* @return Returns true on success or false on failure
+	*/
+	public static function setPermissions($itemType, $itemSource, $shareType, $shareWith, $permissions) {
+		if ($item = self::getItems($itemType, $itemSource, $shareType, $shareWith, \OC_User::getUser(), self::FORMAT_NONE, null, 1, false)) {
+			// Check if this item is a reshare and verify that the permissions granted don't exceed the parent shared item
+			if (isset($item['parent'])) {
+				$query = \OC_DB::prepare('SELECT permissions FROM *PREFIX*share WHERE id = ? LIMIT 1');
+				$result = $query->execute(array($item['parent']))->fetchRow();
+				if (~(int)$result['permissions'] & $permissions) {
+					$message = 'Setting permissions for '.$itemSource.' failed, because the permissions exceed permissions granted to '.\OC_User::getUser();
+					\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+					throw new \Exception($message);
+				}
+			}
+			$query = \OC_DB::prepare('UPDATE *PREFIX*share SET permissions = ? WHERE id = ?');
+			$query->execute(array($permissions, $item['id']));
+			// Check if permissions were removed
+			if ($item['permissions'] & ~$permissions) {
+				// If share permission is removed all reshares must be deleted
+				if (($item['permissions'] & self::PERMISSION_SHARE) && (~$permissions & self::PERMISSION_SHARE)) {
+					self::delete($item['id'], true);
+				} else {
+					$ids = array();
+					$parents = array($item['id']);
+					while (!empty($parents)) {
+						$parents = "'".implode("','", $parents)."'";
+						$query = \OC_DB::prepare('SELECT id, permissions FROM *PREFIX*share WHERE parent IN ('.$parents.')');
+						$result = $query->execute();
+						// Reset parents array, only go through loop again if items are found that need permissions removed
+						$parents = array();
+						while ($item = $result->fetchRow()) {
+							// Check if permissions need to be removed
+							if ($item['permissions'] & ~$permissions) {
+								// Add to list of items that need permissions removed
+								$ids[] = $item['id'];
+								$parents[] = $item['id'];
+							}
+						}
+					}
+					// Remove the permissions for all reshares of this item
+					if (!empty($ids)) {
+						$ids = "'".implode("','", $ids)."'";
+						$query = \OC_DB::prepare('UPDATE *PREFIX*share SET permissions = permissions & ? WHERE id IN ('.$ids.')');
+						$query->execute(array($permissions));
+					}
+				}
+			}
+			return true;
+		}
+		$message = 'Setting permissions for '.$itemSource.' failed, because the item was not found';
+		\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+		throw new \Exception($message);
+	}
+
+	/**
+	* @brief Get the backend class for the specified item type
+	* @param string Item type
+	* @return Sharing backend object
+	*/
+	private static function getBackend($itemType) {
+		if (isset(self::$backends[$itemType])) {
+			return self::$backends[$itemType];
+		} else if (isset(self::$backendTypes[$itemType]['class'])) {
+			$class = self::$backendTypes[$itemType]['class'];
+			if (class_exists($class)) {
+				self::$backends[$itemType] = new $class;
+				if (!(self::$backends[$itemType] instanceof Share_Backend)) {
+					$message = 'Sharing backend '.$class.' must implement the interface OCP\Share_Backend';
+					\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+					throw new \Exception($message);
+				}
+				return self::$backends[$itemType];
+			} else {
+				$message = 'Sharing backend '.$class.' not found';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+		}
+		$message = 'Sharing backend for '.$itemType.' not found';
+		\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+		throw new \Exception($message);
+	}
+
+	/**
+	* @brief Get a list of collection item types for the specified item type
+	* @param string Item type
+	* @return array
+	*/
+	private static function getCollectionItemTypes($itemType) {
+		$collectionTypes = array($itemType);
+		foreach (self::$backendTypes as $type => $backend) {
+			if (in_array($backend['collectionOf'], $collectionTypes)) {
+				$collectionTypes[] = $type;
+			}
+		}
+		if (count($collectionTypes) > 1) {
+			unset($collectionTypes[0]);
+			return $collectionTypes;
+		}
+		return false;
+	}
+
+	/**
+	* @brief Get shared items from the database
+	* @param string Item type
+	* @param string Item source or target (optional)
+	* @param int SHARE_TYPE_USER, SHARE_TYPE_GROUP, SHARE_TYPE_PRIVATE_LINK, $shareTypeUserAndGroups, or $shareTypeGroupUserUnique
+	* @param string User or group the item is being shared with
+	* @param string User that is the owner of shared items (optional)
+	* @param int Format to convert items to with formatItems()
+	* @param mixed Parameters to pass to formatItems()
+	* @param int Number of items to return, -1 to return all matches (optional)
+	* @param bool Include collection item types (optional)
+	* @return mixed
+	*
+	* See public functions getItem(s)... for parameter usage
+	*
+	*/
+	private static function getItems($itemType, $item = null, $shareType = null, $shareWith = null, $uidOwner = null, $format = self::FORMAT_NONE, $parameters = null, $limit = -1, $includeCollections = false, $itemShareWithBySource = false) {
+		$backend = self::getBackend($itemType);
+		// Get filesystem root to add it to the file target and remove from the file source, match file_source with the file cache
+		if ($itemType == 'file' || $itemType == 'folder') {
+			$root = \OC_Filesystem::getRoot();
+			$where = 'INNER JOIN *PREFIX*fscache ON file_source = *PREFIX*fscache.id ';
+			if (!isset($item)) {
+				$where .= 'WHERE file_target IS NOT NULL';
+			}
+			$fileDependent = true;
+			$queryArgs = array();
+		} else {
+			$fileDependent = false;
+			$root = '';
+			if ($includeCollections && !isset($item) && $collectionTypes = self::getCollectionItemTypes($itemType)) {
+				// If includeCollections is true, find collections of this item type, e.g. a music album contains songs
+				$itemTypes = array_merge(array($itemType), $collectionTypes);
+				$placeholders = join(',', array_fill(0, count($itemTypes), '?'));
+				$where = "WHERE item_type IN ('".$placeholders."')";
+				$queryArgs = $itemTypes;
+			} else {
+				$where = 'WHERE item_type = ?';
+				$queryArgs = array($itemType);
+			}
+		}
+		if (isset($shareType) && isset($shareWith)) {
+			// Include all user and group items
+			if ($shareType == self::$shareTypeUserAndGroups) {
+				$where .= ' AND share_type IN (?,?,?)';
+				$queryArgs[] = self::SHARE_TYPE_USER;
+				$queryArgs[] = self::SHARE_TYPE_GROUP;
+				$queryArgs[] = self::$shareTypeGroupUserUnique;
+				$userAndGroups = array_merge(array($shareWith), \OC_Group::getUserGroups($shareWith));
+				$placeholders = join(',', array_fill(0, count($userAndGroups), '?'));
+				$where .= " AND share_with IN (".$placeholders.")";
+				$queryArgs = array_merge($queryArgs, $userAndGroups);
+				// Don't include own group shares
+				$where .= ' AND uid_owner != ?';
+				$queryArgs[] = $shareWith;
+			} else {
+				$where .= ' AND share_type = ? AND share_with = ?';
+				$queryArgs[] = $shareType;
+				$queryArgs[] = $shareWith;
+			}
+		}
+		if (isset($uidOwner)) {
+			$where .= " AND uid_owner = ?";
+			$queryArgs[] = $uidOwner;
+			if (!isset($shareType)) {
+				// Prevent unique user targets for group shares from being selected
+				$where .= " AND share_type != ?";
+				$queryArgs[] = self::$shareTypeGroupUserUnique;
+			}
+			if ($itemType == 'file' || $itemType == 'folder') {
+				$column = 'file_source';
+			} else {
+				$column = 'item_source';
+			}
+		} else {
+			if ($itemType == 'file' || $itemType == 'folder') {
+				$column = 'file_target';
+			} else {
+				$column = 'item_target';
+			}
+		}
+		if (isset($item)) {
+			// If looking for own shared items, check item_source else check item_target
+			if (isset($uidOwner) || $itemShareWithBySource) {
+				// If item type is a file, file source needs to be checked in case the item was converted
+				if ($itemType == 'file' || $itemType == 'folder') {
+					$where .= " AND path = ?";
+					$queryArgs[] = $root.$item;
+				} else {
+					$where .= " AND item_source = ?";
+					$column = 'item_source';
+					$queryArgs[] = $item;
+				}
+			} else {
+				if ($itemType == 'file' || $itemType == 'folder') {
+					$where .= " AND file_target = ?";
+				} else {
+					$where .= " AND item_target = ?";
+				}
+				$queryArgs[] = $item;
+			}
+			if ($includeCollections && $collectionTypes = self::getCollectionItemTypes($itemType)) {
+				// TODO Bart - this doesn't work with only one argument
+// 				$placeholders = join(',', array_fill(0, count($collectionTypes), '?'));
+// 				$where .= " OR item_type IN ('".$placeholders."')";
+// 				$queryArgs = array_merge($queryArgs, $collectionTypes);
+			}
+		}
+		if ($limit != -1 && !$includeCollections) {
+			if ($shareType == self::$shareTypeUserAndGroups) {
+				// Make sure the unique user target is returned if it exists, unique targets should follow the group share in the database
+				// If the limit is not 1, the filtering can be done later
+				$where .= ' ORDER BY *PREFIX*share.id DESC';
+			}
+			// The limit must be at least 3, because filtering needs to be done
+			if ($limit < 3) {
+				$where .= ' LIMIT 3';
+			} else {
+				$where .= ' LIMIT '.$limit;
+			}
+		}
+		// TODO Optimize selects
+		if ($format == self::FORMAT_STATUSES) {
+			if ($itemType == 'file' || $itemType == 'folder') {
+				$select = '*PREFIX*share.id, item_type, *PREFIX*share.parent, share_type, *PREFIX*fscache.path as file_source';
+			} else {
+				$select = 'id, item_type, item_source, parent, share_type';
+			}
+		} else {
+			if (isset($uidOwner)) {
+				if ($itemType == 'file' || $itemType == 'folder') {
+					$select = '*PREFIX*share.id, item_type, *PREFIX*fscache.path as file_source, *PREFIX*share.parent, share_type, share_with, permissions, stime';
+				} else {
+					$select = 'id, item_type, item_source, parent, share_type, share_with, permissions, stime, file_source';
+				}
+			} else {
+				if ($fileDependent) {
+					if (($itemType == 'file' || $itemType == 'folder') && $format == \OC_Share_Backend_File::FORMAT_FILE_APP || $format == \OC_Share_Backend_File::FORMAT_FILE_APP_ROOT) {
+						$select = '*PREFIX*share.id, item_type, *PREFIX*share.parent, share_type, share_with, permissions, file_target, *PREFIX*fscache.id, path as file_source, name, ctime, mtime, mimetype, size, encrypted, versioned, writable';
+					} else {
+						$select = '*PREFIX*share.id, item_type, item_source, item_target, *PREFIX*share.parent, share_type, share_with, uid_owner, permissions, stime, path as file_source, file_target';
+					}
+				} else {
+					$select = '*';
+				}
+			}
+		}
+		$root = strlen($root);
+		$query = \OC_DB::prepare('SELECT '.$select.' FROM *PREFIX*share '.$where);
+		$result = $query->execute($queryArgs);
+		$items = array();
+		$targets = array();
+		while ($row = $result->fetchRow()) {
+			// Filter out duplicate group shares for users with unique targets
+			if ($row['share_type'] == self::$shareTypeGroupUserUnique && isset($items[$row['parent']])) {
+				$row['share_type'] = self::SHARE_TYPE_GROUP;
+				$row['share_with'] = $items[$row['parent']]['share_with'];
+				// Remove the parent group share
+				unset($items[$row['parent']]);
+			} else if (!isset($uidOwner)) {
+				// Check if the same target already exists
+				if (isset($targets[$row[$column]])) {
+					// Check if the same owner shared with the user twice through a group and user share - this is allowed
+					$id = $targets[$row[$column]];
+					if ($items[$id]['uid_owner'] == $row['uid_owner']) {
+						// Switch to group share type to ensure resharing conditions aren't bypassed
+						if ($items[$id]['share_type'] != self::SHARE_TYPE_GROUP) {
+							$items[$id]['share_type'] = self::SHARE_TYPE_GROUP;
+							$items[$id]['share_with'] = $row['share_with'];
+						}
+						// Switch ids if sharing permission is granted on only one share to ensure correct parent is used if resharing
+						if (~(int)$items[$id]['permissions'] & self::PERMISSION_SHARE && (int)$row['permissions'] & self::PERMISSION_SHARE) {
+							$items[$row['id']] = $items[$id];
+							unset($items[$id]);
+							$id = $row['id'];
+						}
+						// Combine the permissions for the item
+						$items[$id]['permissions'] |= (int)$row['permissions'];
+						continue;
+					}
+				} else {
+					$targets[$row[$column]] = $row['id'];
+				}
+			}
+			// Remove root from file source paths if retrieving own shared items
+			if (isset($uidOwner) && isset($row['file_source'])) {
+				if (isset($row['parent'])) {
+					$row['file_source'] = '/Shared/'.basename($row['file_source']);
+				} else {
+					$row['file_source'] = substr($row['file_source'], $root);
+				}
+			}
+			$items[$row['id']] = $row;
+		}
+		if (!empty($items)) {
+			$collectionItems = array();
+			foreach ($items as &$row) {
+				// Return only the item instead of a 2-dimensional array
+				if ($limit == 1 && $row['item_type'] == $itemType && $row[$column] == $item) {
+					if ($format == self::FORMAT_NONE) {
+						return $row;
+					} else {
+						break;
+					}
+				}
+				// Check if this is a collection of the requested item type
+				if ($includeCollections && $row['item_type'] != $itemType && $collectionBackend = self::getBackend($row['item_type']) && $collectionBackend instanceof Share_Backend_Collection) {
+					$row['collection'] = array('item_type' => $itemType, $column => $row[$column]);
+					// Fetch all of the children sources
+					$children = $collectionBackend->getChildren($row[$column]);
+					foreach ($children as $child) {
+						$childItem = $row;
+						$childItem['item_source'] = $child;
+// 						$childItem['item_target'] = $child['target']; TODO
+						if (isset($item)) {
+							if ($childItem[$column] == $item) {
+								// Return only the item instead of a 2-dimensional array
+								if ($limit == 1 && $format == self::FORMAT_NONE) {
+									return $childItem;
+								} else {
+									// Unset the items array and break out of both loops
+									$items = array();
+									$items[] = $childItem;
+									break 2;
+								}
+							}
+						} else {
+							$collectionItems[] = $childItem;
+						}
+					}
+					// Remove collection item
+					unset($items[$row['id']]);
+				}
+			}
+			if (!empty($collectionItems)) {
+				$items = array_merge($items, $collectionItems);
+			}
+			if ($format == self::FORMAT_NONE) {
+				return $items;
+			} else if ($format == self::FORMAT_STATUSES) {
+				$statuses = array();
+				foreach ($items as $item) {
+					if ($item['share_type'] == self::SHARE_TYPE_PRIVATE_LINK) {
+						$statuses[$item[$column]] = true;
+					} else if (!isset($statuses[$item[$column]])) {
+						$statuses[$item[$column]] = false;
+					}
+				}
+				return $statuses;
+			} else {
+				return $backend->formatItems($items, $format, $parameters);
+			}
+		} else if ($limit == 1 || (isset($uidOwner) && isset($item))) {
+			return false;
+		}
+		return array();
+	}
+
+	/**
+	* @brief Put shared item into the database
+	* @param string Item type
+	* @param string Item source
+	* @param int SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_PRIVATE_LINK
+	* @param string User or group the item is being shared with
+	* @param int CRUDS permissions
+	* @param bool|array Parent folder target (optional)
+	* @return bool Returns true on success or false on failure
+	*/
+	private static function put($itemType, $itemSource, $shareType, $shareWith, $uidOwner, $permissions, $parentFolder = null) {
+		// Check file extension for an equivalent item type to convert to
+		if ($itemType == 'file') {
+			$extension = strtolower(substr($itemSource, strrpos($itemSource, '.') + 1));
+			foreach (self::$backends as $type => $backend) {
+				if (isset($backend->dependsOn) && $backend->dependsOn == 'file' && isset($backend->supportedFileExtensions) && in_array($extension, $backend->supportedFileExtensions)) {
+					$itemType = $type;
+					break;
+				}
+			}
+			// Exit if this is being called for a file inside a folder, and no equivalent item type is found
+			if (isset($parentFolder) && $itemType == 'file') {
+				return false;
+			}
+		}
+		$backend = self::getBackend($itemType);
+		// Check if this is a reshare
+		if ($checkReshare = self::getItemSharedWithBySource($itemType, $itemSource, self::FORMAT_NONE, null, true)) {
+			// Check if attempting to share back to owner
+			if ($checkReshare['uid_owner'] == $shareWith && $shareType == self::SHARE_TYPE_USER) {
+				$message = 'Sharing '.$itemSource.' failed, because the user '.$shareWith.' is the original sharer';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			// Check if attempting to share back to group TODO Check unique user target
+			} else if ($shareType == self::SHARE_TYPE_GROUP && $checkReshare['share_with'] == $shareWith['group']) {
+				$message = 'Sharing '.$itemSource.' failed, because the item was orignally shared with the group '.$shareWith['group'];
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			// Check if attempting to share back a group share to a member of the same group
+			} else if (($checkReshare['share_type'] == self::SHARE_TYPE_GROUP || $checkReshare['share_type'] == self::$shareTypeGroupUserUnique) && $shareType == self::SHARE_TYPE_USER) {
+				if ($checkReshare['share_type'] == self::$shareTypeGroupUserUnique) {
+					$query = \OC_DB::prepare('SELECT share_with FROM *PREFIX*share WHERE id = ?');
+					$group = $query->execute(array($checkReshare['parent']))->fetchOne();
+				} else {
+					$group = $checkReshare['share_with'];
+				}
+				if (\OC_Group::inGroup($shareWith, $group)) {
+					$message = 'Sharing '.$itemSource.' failed, because the user '.$shareWith.' is a member of the original group share';
+					\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+					throw new \Exception($message);
+				}
+			}
+			// Check if share permissions is granted
+			if ((int)$checkReshare['permissions'] & self::PERMISSION_SHARE) {
+				if (~(int)$checkReshare['permissions'] & $permissions) {
+					$message = 'Sharing '.$itemSource.' failed, because the permissions exceed permissions granted to '.$uidOwner;
+					\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+					throw new \Exception($message);
+				} else {
+					// TODO Don't check if inside folder
+					$parent = $checkReshare['id'];
+					$itemSource = $checkReshare['item_source'];
+					// TODO Suggest item/file target
+					$suggestedItemTarget = $checkReshare['item_target'];
+					$fileSource = $checkReshare['file_source'];
+					$filePath = $checkReshare['file_target'];
+				}
+			} else {
+				$message = 'Sharing '.$itemSource.' failed, because resharing is not allowed';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+		} else {
+			$parent = null;
+			if (!$backend->isValidSource($itemSource, $uidOwner)) {
+				$message = 'Sharing '.$itemSource.' failed, because the sharing backend for '.$itemType.' could not find its source';
+				\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+				throw new \Exception($message);
+			}
+			$parent = null;
+			if ($backend instanceof Share_Backend_File_Dependent) {
+				// NOTE Apps should start using the file cache ids in their tables
+				$filePath = $backend->getFilePath($itemSource, $uidOwner);
+				$fileSource = \OC_FileCache::getId($filePath);
+				if ($fileSource == -1) {
+					$message = 'Sharing '.$itemSource.' failed, because the file could not be found in the file cache';
+					\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+					throw new \Exception($message);
+				}
+			} else {
+				$filePath = null;
+				$fileSource = null;
+			}
+		}
+		$query = \OC_DB::prepare('INSERT INTO *PREFIX*share (item_type, item_source, item_target, parent, share_type, share_with, uid_owner, permissions, stime, file_source, file_target) VALUES (?,?,?,?,?,?,?,?,?,?,?)');
+		// Share with a group
+		if ($shareType == self::SHARE_TYPE_GROUP) {
+			if (isset($fileSource)) {
+				if ($parentFolder) {
+					if ($parentFolder === true) {
+						$groupFileTarget = self::generateTarget('file', $filePath, $shareType, $shareWith['group'], $uidOwner);
+						// Set group default file target for future use
+						$parentFolders[0]['folder'] = $groupFileTarget;
+					} else {
+						// Get group default file target
+						$groupFileTarget = $parentFolder[0]['folder'].$itemSource;
+						$parent = $parentFolder[0]['id'];
+						unset($parentFolder[0]);
+						// Only loop through users we know have different file target paths
+						$uidSharedWith = array_keys($parentFolder);
+					}
+				} else {
+					$groupFileTarget = self::generateTarget('file', $filePath, $shareType, $shareWith['group'], $uidOwner);
+				}
+			} else {
+				$groupFileTarget = null;
+			}
+			$groupItemTarget = self::generateTarget($itemType, $itemSource, $shareType, $shareWith['group'], $uidOwner);
+			$uniqueTargets = array();
+			// Loop through all users of this group in case we need to add an extra row
+			foreach ($shareWith['users'] as $uid) {
+				$itemTarget = self::generateTarget($itemType, $itemSource, self::SHARE_TYPE_USER, $uid, $uidOwner);
+				if (isset($fileSource)) {
+					if ($parentFolder) {
+						if ($parentFolder === true) {
+							$fileTarget = self::generateTarget('file', $filePath, self::SHARE_TYPE_USER, $uid, $uidOwner);
+							if ($fileTarget != $groupFileTarget) {
+								$parentFolders[$uid]['folder'] = $fileTarget;
+							}
+						} else if (isset($parentFolder[$uid])) {
+							$fileTarget = $parentFolder[$uid]['folder'].$itemSource;
+							$parent = $parentFolder[$uid]['id'];
+						}
+					} else {
+						$fileTarget = self::generateTarget('file', $filePath, self::SHARE_TYPE_USER, $uid, $uidOwner);
+					}
+				} else {
+					$fileTarget = null;
+				}
+				// Insert an extra row for the group share if the item or file target is unique for this user
+				if ($itemTarget != $groupItemTarget || (isset($fileSource) && $fileTarget != $groupFileTarget)) {
+					$uniqueTargets[] = array('uid' => $uid, 'item_target' => $itemTarget, 'file_target' => $fileTarget);
+				}
+			}
+			$query->execute(array($itemType, $itemSource, $groupItemTarget, $parent, $shareType, $shareWith['group'], $uidOwner, $permissions, time(), $fileSource, $groupFileTarget));
+			// Save this id, any extra rows for this group share will need to reference it
+			$parent = \OC_DB::insertid('*PREFIX*share');
+			foreach ($uniqueTargets as $unique) {
+				$query->execute(array($itemType, $itemSource, $unique['item_target'], $parent, self::$shareTypeGroupUserUnique, $unique['uid'], $uidOwner, $permissions, time(), $fileSource, $unique['file_target']));
+				$id = \OC_DB::insertid('*PREFIX*share');
+				if ($parentFolder === true) {
+					$parentFolders['id'] = $id;
+				}
+			}
+			if ($parentFolder === true) {
+				// Return parent folders to preserve file target paths for potential children
+				return $parentFolders;
+			}
+		} else {
+			$itemTarget = self::generateTarget($itemType, $itemSource, $shareType, $shareWith, $uidOwner);
+			if (isset($fileSource)) {
+				if ($parentFolder) {
+					if ($parentFolder === true) {
+						$fileTarget = self::generateTarget('file', $filePath, $shareType, $shareWith, $uidOwner);
+						$parentFolders['folder'] = $fileTarget;
+					} else {
+						$fileTarget = $parentFolder['folder'].$itemSource;
+						$parent = $parentFolder['id'];
+					}
+				} else {
+					$fileTarget = self::generateTarget('file', $filePath, $shareType, $shareWith, $uidOwner);
+				}
+			} else {
+				$fileTarget = null;
+			}
+			$query->execute(array($itemType, $itemSource, $itemTarget, $parent, $shareType, $shareWith, $uidOwner, $permissions, time(), $fileSource, $fileTarget));
+			$id = \OC_DB::insertid('*PREFIX*share');
+			if ($parentFolder === true) {
+				$parentFolders['id'] = $id;
+				// Return parent folder to preserve file target paths for potential children
+				return $parentFolders;
+			}
+		}
+		return true;
+	}
+
+	/**
+	* @brief Generate a unique target for the item
+	* @param string Item type
+	* @param string Item source
+	* @param int SHARE_TYPE_USER, SHARE_TYPE_GROUP, or SHARE_TYPE_PRIVATE_LINK
+	* @param string User or group the item is being shared with
+	* @return string Item target
+	*
+	* TODO Use a suggested item target by default
+	*
+	*/
+	private static function generateTarget($itemType, $itemSource, $shareType, $shareWith, $uidOwner) {
+		$backend = self::getBackend($itemType);
+		if ($shareType == self::SHARE_TYPE_PRIVATE_LINK) {
+			return $backend->generateTarget($itemSource, false);
+		} else {
+			if ($itemType == 'file' || $itemType == 'folder') {
+				$column = 'file_target';
+			} else {
+				$column = 'item_target';
+			}
+			if ($shareType == self::SHARE_TYPE_USER) {
+				// Share with is a user, so set share type to user and groups
+				$shareType = self::$shareTypeUserAndGroups;
+				$userAndGroups = array_merge(array($shareWith), \OC_Group::getUserGroups($shareWith));
+			} else {
+				$userAndGroups = false;
+			}
+			$exclude = null;
+			// Backend has 3 opportunities to generate a unique target
+			for ($i = 0; $i < 2; $i++) {
+				if ($shareType == self::SHARE_TYPE_GROUP) {
+					$target = $backend->generateTarget($itemSource, false, $exclude);
+				} else {
+					$target = $backend->generateTarget($itemSource, $shareWith, $exclude);
+				}
+				if (is_array($exclude) && in_array($target, $exclude)) {
+					break;
+				}
+				// Check if target already exists
+				if ($checkTarget = self::getItems($itemType, $target, $shareType, $shareWith, null, self::FORMAT_NONE, null, 1)) {
+					// If matching target is from the same owner, use the same target. The share type will be different so this isn't the same share.
+					if ($checkTarget['uid_owner'] == $uidOwner) {
+						return $target;
+					}
+					if (!isset($exclude)) {
+						$exclude = array();
+					}
+					// Find similar targets to improve backend's chances to generate a unqiue target
+					if ($userAndGroups) {
+						$checkTargets = \OC_DB::prepare("SELECT ".$column." FROM *PREFIX*share WHERE item_type = ? AND share_type IN (?,?,?) AND share_with IN ('".implode("','", $userAndGroups)."') AND ".$column." LIKE ?");
+						$result = $checkTargets->execute(array($itemType, self::SHARE_TYPE_USER, self::SHARE_TYPE_GROUP, self::$shareTypeGroupUserUnique, '%'.$target.'%'));
+					} else {
+						$checkTargets = \OC_DB::prepare("SELECT ".$column." FROM *PREFIX*share WHERE item_type = ? AND share_type = ? AND share_with = ? AND ".$column." LIKE ?");
+						$result = $checkTargets->execute(array($itemType, self::SHARE_TYPE_GROUP, $shareWith, '%'.$target.'%'));
+					}
+					while ($row = $result->fetchRow()) {
+						$exclude[] = $row[$column];
+					}
+				} else {
+					return $target;
+				}
+			}
+		}
+		$message = 'Sharing backend registered for '.$itemType.' did not generate a unique target for '.$itemSource;
+		\OC_Log::write('OCP\Share', $message, \OC_Log::ERROR);
+		throw new \Exception($message);
+	}
+
+	/**
+	* @brief Delete all reshares of an item
+	* @param int Id of item to delete
+	* @param bool If true, exclude the parent from the delete (optional)
+	* @param string The user that the parent was shared with (optinal)
+	*/
+	private static function delete($parent, $excludeParent = false, $uidOwner = null) {
+		$ids = array($parent);
+		$parents = array($parent);
+		while (!empty($parents)) {
+			$parents = "'".implode("','", $parents)."'";
+			// Check the owner on the first search of reshares, useful for finding and deleting the reshares by a single user of a group share
+			if (count($ids) == 1 && isset($uidOwner)) {
+				$query = \OC_DB::prepare('SELECT id FROM *PREFIX*share WHERE parent IN ('.$parents.') AND uid_owner = ?');
+				$result = $query->execute(array($uidOwner));
+			} else {
+				$query = \OC_DB::prepare('SELECT id, item_type, item_target, parent, uid_owner FROM *PREFIX*share WHERE parent IN ('.$parents.')');
+				$result = $query->execute();
+			}
+			// Reset parents array, only go through loop again if items are found
+			$parents = array();
+			while ($item = $result->fetchRow()) {
+				// Search for a duplicate parent share, this occurs when an item is shared to the same user through a group and user or the same item is shared by different users
+				$userAndGroups = array_merge(array($item['uid_owner']), \OC_Group::getUserGroups($item['uid_owner']));
+				$query = \OC_DB::prepare("SELECT id, permissions FROM *PREFIX*share WHERE item_type = ? AND item_target = ? AND share_type IN (?,?,?) AND share_with IN ('".implode("','", $userAndGroups)."') AND uid_owner != ? AND id != ?");
+				$duplicateParent = $query->execute(array($item['item_type'], $item['item_target'], self::SHARE_TYPE_USER, self::SHARE_TYPE_GROUP, self::$shareTypeGroupUserUnique, $item['uid_owner'], $item['parent']))->fetchRow();
+				if ($duplicateParent) {
+					// Change the parent to the other item id if share permission is granted
+					if ($duplicateParent['permissions'] & self::PERMISSION_SHARE) {
+						$query = \OC_DB::prepare('UPDATE *PREFIX*share SET parent = ? WHERE id = ?');
+						$query->execute(array($duplicateParent['id'], $item['id']));
+						continue;
+					}
+				}
+				$ids[] = $item['id'];
+				$parents[] = $item['id'];
+			}
+		}
+		if ($excludeParent) {
+			unset($ids[0]);
+		}
+		if (!empty($ids)) {
+			$ids = "'".implode("','", $ids)."'";
+			$query = \OC_DB::prepare('DELETE FROM *PREFIX*share WHERE id IN ('.$ids.')');
+			$query->execute();
+		}
+	}
+
+	/**
+	* Hook Listeners
+	*/
+
+	public static function post_deleteUser($arguments) {
+		// Delete any items shared with the deleted user
+		$query = \OC_DB::prepare('DELETE FROM *PREFIX*share WHERE share_with = ? AND share_type = ? OR share_type = ?');
+		$result = $query->execute(array($arguments['uid'], self::SHARE_TYPE_USER, self::$shareTypeGroupUserUnique));
+		// Delete any items the deleted user shared
+		$query = \OC_DB::prepare('SELECT id FROM *PREFIX*share WHERE uid_owner = ?');
+		$result = $query->execute(array($arguments['uid']));
+		while ($item = $result->fetchRow()) {
+			self::delete($item['id']);
+		}
+	}
+
+	public static function post_addToGroup($arguments) {
+		// TODO
+	}
+
+	public static function post_removeFromGroup($arguments) {
+		// TODO Don't call if user deleted?
+		$query = \OC_DB::prepare('SELECT id, share_type FROM *PREFIX*share WHERE (share_type = ? AND share_with = ?) OR (share_type = ? AND share_with = ?)');
+		$result = $query->execute(array(self::SHARE_TYPE_GROUP, $arguments['gid'], self::$shareTypeGroupUserUnique, $arguments['uid']));
+		while ($item = $result->fetchRow()) {
+			if ($item['share_type'] == self::SHARE_TYPE_GROUP) {
+				// Delete all reshares by this user of the group share
+				self::delete($item['id'], true, $arguments['uid']);
+			} else {
+				self::delete($item['id']);
+			}
+		}
+	}
+
+}
+
+/**
+* Interface that apps must implement to share content.
+*/
+interface Share_Backend {
+
+	/**
+	* @brief Get the source of the item to be stored in the database
+	* @param string Item source
+	* @param string Owner of the item
+	* @return mixed|array|false Source
+	*
+	* Return an array if the item is file dependent, the array needs two keys: 'item' and 'file'
+	* Return false if the item does not exist for the user
+	*
+	* The formatItems() function will translate the source returned back into the item
+	*/
+	public function isValidSource($itemSource, $uidOwner);
+
+	/**
+	* @brief Get a unique name of the item for the specified user
+	* @param string Item source
+	* @param string|false User the item is being shared with
+	* @param array|null List of similar item names already existing as shared items
+	* @return string Target name
+	*
+	* This function needs to verify that the user does not already have an item with this name.
+	* If it does generate a new name e.g. name_#
+	*/
+	public function generateTarget($itemSource, $shareWith, $exclude = null);
+
+	/**
+	* @brief Converts the shared item sources back into the item in the specified format
+	* @param array Shared items
+	* @param int Format
+	* @return ?
+	*
+	* The items array is a 3-dimensional array with the item_source as the first key and the share id as the second key to an array with the share info.
+	* The key/value pairs included in the share info depend on the function originally called:
+	* If called by getItem(s)Shared: id, item_type, item, item_source, share_type, share_with, permissions, stime, file_source
+	* If called by getItem(s)SharedWith: id, item_type, item, item_source, item_target, share_type, share_with, permissions, stime, file_source, file_target
+	* This function allows the backend to control the output of shared items with custom formats.
+	* It is only called through calls to the public getItem(s)Shared(With) functions.
+	*/
+	public function formatItems($items, $format, $parameters = null);
+
+}
+
+/**
+* Interface for share backends that share content that is dependent on files.
+* Extends the Share_Backend interface.
+*/
+interface Share_Backend_File_Dependent extends Share_Backend {
+
+	/**
+	* @brief Get the file path of the item
+	* @param
+	* @param
+	* @return
+	*/
+	public function getFilePath($itemSource, $uidOwner);
+
+}
+
+/**
+* Interface for collections of of items implemented by another share backend.
+* Extends the Share_Backend interface.
+*/
+interface Share_Backend_Collection extends Share_Backend {
+
+	/**
+	* @brief Get the sources of the children of the item
+	* @param string Item source
+	* @return array Returns an array of sources
+	*/
+	public function getChildren($itemSource);
+
+}
+
+?>