dip.plugins

The dip.plugins module implements the infrastructure for encapsulating application plugins.

ExtensionPoint

class dip.plugins.ExtensionPoint

Base class: Model

The ExtensionPoint class is the default implementation of an extension point.

bind(obj, name)

Bind an attribute of an object to the extension point and update it with all contributions made so far.

Parameters:

• obj – is the object containing the attribute to bind to.
• name – is the name of the attribute to bind to.

contribute(contribution)

Contribute an object to all bound attributes.

Parameters:contribution – is the object to contribute.

IExtensionPoint

class dip.plugins.IExtensionPoint

Base class: Interface

The IExtensionPoint interface defines the API of an extension point.

contributions = List()

The list of contributions made.

id = Str()

The identifier of the extension point.

bind(obj, name)

Bind an attribute of an object to the extension point and update it with all contributions made so far.

Parameters:

• obj – is the object containing the attribute to bind to.
• name – is the name of the attribute to bind to.

contribute(contribution)

Contribute an object to all bound attributes.

Parameters:contribution – is the object to contribute.

IPlugin

class dip.plugins.IPlugin

Base class: Interface

The IPlugin interface defines the API of a plugin.

enabled = Bool(True)

This is set if the plugin is enabled.

id = Str()

The identifier of the plugin. Two plugins are considered equivalent if their factories have the same identifier, even though the factories themselves are different.

requires = List(Str())

The list of identifiers of plugins that must be enabled before this one can be enabled.

configure(plugin_manager)

This is called when the plugin is enabled to ask that it configures itself.

Parameters:plugin_manager – the plugin manager.

IPluginManager

class dip.plugins.IPluginManager

Base class: Interface

The IPluginManager interface defines the API of a plugin manager.

extension_points = List(IExtensionPoint)

The list of extension points.

plugins = List(IPlugin)

The list of contributed plugins.

services = List(IService)

The list of contributed services.

bind_extension_point(id, obj, name)

Bind an extension point to an attribute of an object. The attribute must have an append() method.

Parameters:

• id – is the identifier of the extension point.
• obj – is the object containing the attribute that the extension point is bound to.
• name – is the name of the attribute that the extension point is bound to.

bind_service(interface, obj, name)

Bind the service for an interface to an attribute of an object.

Parameters:

• interface – is the interface.
• obj – is the object containing the attribute that the service is bound to.
• name – is the name of the attribute that the service is bound to.

choose_service(services)

Choose a particular service from a list of possible services.

Parameters:services – a list of contributed services to choose from. Returns:the chosen service or None if one wasn’t chosen.

contribute(id, contribution)

Contribute an object to an extension point.

Parameters:

• id – is the identifier of the extension point.
• contribution – is the contribution to make to the extension point.

service(interface)

Get a service for a particular interface.

Parameters:interface – is the interface. Returns:the service which will implement or be able to be adapted to the interface. An exception is raised if there is no service available.

IService

class dip.plugins.IService

Base class: Interface

The IService interface defines the API of a service definition.

implementation = Any()

The service implementation.

interface = Subclass(Interface)

The interface that the service implements.

PluginManager

class dip.plugins.PluginManager

Base class: Singleton

The PluginManager class is a singleton that provides access to a default plugin manager.

instance = Instance(IPluginManager)

The plugin manager instance.

classmethod add_plugin(plugin)

Add a plugin to the plugin manager.

Parameters:plugin – is the plugin.

Service

class dip.plugins.Service

Base class: Model

The Service class is the default implementation of a service definition.