How do Joomla! 'one-click' updates work?

Question

My Joomla! CMS administration dashboard notifies me when an update to an extension is available.

I then use the 'one-click' update and that extension gets updated.

How do these 'one-click' updates work?

Does Joomla! have a 'central database' of extension versions that the Joomla! CMS checks against? (i.e. a centralized system that keeps track).

Or does each extension provider run their own 'update servers' which the Joomla! CMS checks against?

What's happening 'behind the scenes' to make 'one-click' updates work?

Answer 1

Each extension provider creates their own update server which is specified in the manifest file included with the extension. Here is the Joomla! documentation on deploying an update server.

While this sounds complicated, it is actually really simple. At it's most basic, the server consists of an XML file that tells Joomla! where to find each available version of the extension. Joomla! selects the appropriate version and retrieves it from the location specified by the server.

Answer 2

Each extension provider runs their own "update server", the location of which is contained within the extension manifest xml file.

For further information

• http://docs.joomla.org/Deploying_an_Update_Server
• http://docs.joomla.org/J3.2:Creating_a_simple_module/Adding_Auto_Update