Application tuning


PyAMS application configuration is done via several complementary ways:

  • via Pyramid’s configuration files located in ‘etc/’ folder
  • via ZCML files .
  • via Site Management to setup Local utilities defined into ZODB (see Site Manager guide)

Pyramid’s configuration files

PyAMS is using default Pyramid’s ini configuration files to define settings. When using default PyAMS scaffold, these INI files are stored into etc folder. Two files are created by scaffold: a development file (development.ini) and a production file (production.ini) which contain nearly the same directives, except for debug toolbar (activated only in development), Fanstatic configuration and logging.

These files are actually documented, but here are a few important directives:

  • zodbconn.uri: (ex: zconfig:/zodb-relstorage.conf)
  • pyams.application_name: Name of your own application
  • pyams.application_factory: Configuration module path to your custom application.
  • pyams_xxx.tcp_handler : Adress of the tcp handler for the service associated to the pyams package
  • pyams_xxx.start_handler: True / False
  • pyams_content.config.xxx_tool_factory and pyams_content.config.xxx_tool_name: You can override default factory by defining these settings or by providing your own adapters.

Pyramid’s configuration files powered by PyAMS_utils

On application startup, if PyAMS_utils package is included into Pyramid configuration, several operations take place:

  • a custom site factory is defined
  • custom request methods are defined
  • a custom traverser handling namespaces is defined
  • a custom subscribers predicate based on interfaces support is defined
  • several adapters are registered, to handle annotations and key references
  • custom TALES extensions are registered.

The site factory is an important component in this process. It is this factory which will define the application root and create a local site manager.

Pyramid application is loaded from ZODB’s root via a key defined in Pyramid’s configuration file; the key is named pyams.application_name and it’s default value is application.

If the application can’t be found, PyAMS is looking for an application class name in Pyramid’s configuration file; the class name configuration key is called pyams.application_factory and defined by default as PyAMS default site factory will then create the application, and add a local site manager to it (see Zope Component Architecture with PyAMS).

After application creation, a NewLocalSiteCreatedEvent is notified. Custom packages can subscribe to this event to register custom components.

ZCML configuration files

Adding more ZCML configuration directives is not mandatory in any way but can be useful in several use cases. For example, templates can’t be overriden via Python annotations without creating a new subclass; this can be done easily via ZCML.