collective.saconnect 1.0

A Plone control panel for SQL Alchemy connection strings

Introduction

This package provides a simple control panel and storage for SQLAlchemy connection strings. It presents a form where one can add and remove named connections, and a GS import and export step to manage these.

This package does not provide SQLAlchemy integration itself; use a library like zope.sqlalchemy or collective.lead instead.

Example usage:

from zope.app.component.hooks import getSite
from collective.saconnect.interfaces import ISQLAlchemyConnectionStrings

saconnect = ISQLAlchemyConnectionStrings(getSite())
myconnection = saconnect['myidentifier']

ISQLAlchemyConnectionStrings acts as a simple dictionary, although it’s keys and values must be simple strings.

To import connection strings through GenericSetup, simply include a file named saconnections.xml in your profile, with a top-level ‘connections’ element and one ‘connection’ element per connection, with name and string attributes:

<?xml version="1.0"?>
<connections>
 <connection name="bar" string="sqlite:////path/to/bar.sqlite"/>
 <connection name="foo" string="oracle://username:password/tnsnamethere"/>
</connections>

To remove any of the connections, use the ‘remove’ attribute:

<?xml version="1.0"?>
<connections>
  <connection name="bar" remove=""/>
</connections>

If you cache your SQLAlchemy connections, you may want to listen for the IObjectModifiedEvent for ISQLAlchemyConnectionStrings; the event includes the key of the modified string, so you can easily refresh your database connections:

<subscriber
    handler=".mymodule.saconnectionUpdated"
    for="collective.saconnect.interfaces.ISQLAlchemyConnectionStrings
         zope.lifecycleevent.interfaces.IObjectModifiedEvent"
    />
def saconnectionUpdated(connections, event):
    if 'myconnectionstring' in event.descriptions:
        getUtility(IDatabase, u'myconnection').invalidate()

Credits

Development sponsored by

Elkjøp Nordic AS

Design and development

Martijn Pieters at Jarn

Changelog

1.0 - 2009-03-17

• Initial release [mj]