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Santhosh/Rajaram|modified extensions section in README

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Rajaram Mallya 2011-07-26 14:10:54 +05:30
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@ -108,26 +108,32 @@ There are a few requirements to writing your own plugin:
# -- Extensions
1) Creating Extensions:
An example extension exists in ./tests/unit/extensions/foxinsocks.py
The unit tests in ./tests/unit/test_extensions.py document the complete
set of extension features supported
2) Loading Extension:
a) The extension file should have a class with same name as the filename.
a) Extension files should be placed under ./extensions folder.
b) The extension file should have a class with the same name as the filename.
This class should implement the contract required by the extension framework.
See ExtensionDescriptor class in ./quantum/common/extensions.py for details
For an example look at Foxinsocks class in foxinsocks.py
b) The extension file should be deployed in the ./extensions folder.
If the filename starts with an "_", it will not be treated as an extension.
3) Plugins advertizing extension support:
A Plugin can advertize all the extensions it supports through the
'supported_extension_aliases' attribute. Eg:
c) To stop a file in ./extensions folder from being loaded as an extension,
the filename should start with an "_"
For an example of an extension file look at Foxinsocks class in
./tests/unit/extensions/foxinsocks.py
The unit tests in ./tests/unit/test_extensions.py document all the ways in
which you can use extensions
2) Associating plugins with extensions:
a) A Plugin can advertize all the extensions it supports through the
'supported_extension_aliases' attribute. Eg:
class SomePlugin:
...
supported_extension_aliases = ['extension1_alias',
class SomePlugin:
...
supported_extension_aliases = ['extension1_alias',
'extension2_alias',
'extension3_alias']
4) Standardizing extensions:
An extension might be supported by multiple plugins. In such cases, the extension
can mandate an interface that all plugins have to support for that extension.
For an example see the FoxInSocksPluginInterface in foxinsocks.py and the QuantumEchoPlugin
Any extension not in this list will not be loaded for the plugin
b) Extension Interfaces for plugins (optional)
The extension can mandate an interface that plugins have to support with the
'get_plugin_interface' method in the extension.
For an example see the FoxInSocksPluginInterface in foxinsocks.py.
The QuantumEchoPlugin lists foxinsox in its supported_extension_aliases
and implements the method from FoxInSocksPluginInterface.