[server] implement dynamic database pooler
Opening too much database connection has a cost at startup and also PostgreSQL
as a maximum number of connection (100 by default).
This get worse when starting multiple wsgi processes, since each process has
its own database pool.
Instead of opening `connections-pool-size` connections to the database at
startup, just open one and open more only when needed.
.. _ajax:
Ajax
----
.. warning::
This approach is deprecated in favor of using
`cwclientlibjs <https://www.npmjs.com/package/@logilab/cwclientlibjs>`_.
If your use react for your UI, try the react components from the
`cwelements <https://www.npmjs.com/package/@logilab/cwelements>`_ library.
The documentation is kept here as reference.
For historical reference of what Ajax is and used to be, one can read the
`wikipedia article about Ajax <https://en.wikipedia.org/wiki/Ajax_(programming)>`_.
CubicWeb provides a few helpers to facilitate *javascript <-> python* communications.
You can, for instance, register some python functions that will become
callable from javascript through ajax calls. All the ajax URLs are handled
by the :class:`cubicweb.web.views.ajaxcontroller.AjaxController` controller.
.. automodule:: cubicweb.web.views.ajaxcontroller