features:

• adds sharing buttons to appropriate locations in elgg - currently adds a sidebar module to appropriate elgg pages and buttons to the bottom of profile info boxes (you can edit start.php to change this).
• optionally adds a set of icons to the footer of the site to allow users to follow the site itself on other networks.
• 2 button styles are available - micro and a larger style that includes the names of target networks.
• passes appropriate images/thumbnails and text to target sites for sharing.
• adds opengraph and standard metatags to each page header to ensure sites that use metatag fields (e.g. og:image)
• adds descriptive text and titles to common pages in elgg which otherwise would be non-unique.
• adds profile buttons for social site profiles belonging to profile owner (using profile_manager fields).
• supports common elgg objects such as videolist, tidypics, blogs, pages, bookmarks, files and pinboards etc. (sharing items from pages created by other 3rd party plugins may function correctly or may not - these plugins are not all tested).
• supports site-wide categories and the hypecategories plugin.
• allows twitter tweets to be linked automatically to a twitter handle that is specific for your site (requires admin setting to be configured).
• code is lightweight and does not use external server connections until sharing occurs.
• can be extended to include more target sites - will be made easier in future releases.
• includes a widget for homepage_cms (could be used for other areas of elgg if desired).
• all text is multi-language compatible.
• supports profile manager's custom field features to allow profile/group data, such as 'about me' for profiles, to be shared (requires field names being configured in the admin settings for this plugin).
• allows different sized images to be used when sharing the homepage or other areas of the site which do not have images (large or small version images).
• intelligently chooses images to be used if no icons are available - may use group icon, item container, item owner or site default images.
• supports profile_url plugin.
• uses url sniffing to be view independent - so you can 'theoretically' use the views in this plugin anywhere on an elgg site.
• does not allow non-public items (and unpublished blogs) to be shared since they cannot be seen by recipient sites.
• supports the pagehandler_hijack plugin feature of changing the url path of different parts of the site.
• supports the donation modules.
• there is no javascript loaded at all by this plugin: no javascript from external sites is used and the button images are intentionally stored locally so that connections to external servers only occur when shares are intentionally made, rather than on every page load - this is to support privacy and limit the use of social network as spying devices.
• if entities are shared from an edit page or non 'view' mode page, the resulting url will point to the 'view' version of the page.

see in use @ ureka: https://www.ureka.org

requires: server php version > 5.3

install:

1. deactivate and remove any previous version of the plugin from the mod folder
2. extract the zip file for this plugin and move the extracted files into the mod folder
3. activate the plugin.
4. optional: create profile fields in profile_manager for social profiles. they should be of type 'url'. currently the supported sites are as follows:

• youtube (name the profile field as: youtube)
• google+ (name the profile field as: googleplus)
• twitter (name the profile field as: twitter)
• facebook (name the profile field as: facebook)
• linked in (name the profile field as: linkedin)

n.b. you will need to edit the /views/default/page/elements/html.php file to include the opengraph namespace before your pages will fully comply with the opengraph standard. this plugin does not include the change since this file is such a fundamental file of an elgg installation. to make the change yourself you only need to add the following tag inside the tag: xmlns:og="http://ogp.me/ns#" so the full html tag will look similar to this:

html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://ogp.me/ns#" xml:lang="en" lang="en"

notes:

• og:author is not included because facebook uses that to point to a facebook profile and if we add data to that field that contains spaces, the facebook validator will error.
• og:image for groups - there are not master icons available for groups in elgg... which results in fb complaining that some group images are too small.
• facebook's sharer page and opengraph code is sometimes glitchy - even when image paths are passed directly to facebook they sometimes do not render - regardless of whether the facebook opengraph debugger throws an error or not.
• to test opengraph metatags for your pages, you could use the script at: http://ogp.spypixel.com/Pogo/checker/index.php or the facebook debugger: https://developers.facebook.com/tools/debug/

 thanks to steve clay - this plugin uses the url sniffer code for elgg that he created.