= Egg cooking = Since Trac 0.9 it has been possible to write plugins for Trac to extend Trac functionality. Even better, you can deploy plugins as [http://peak.telecommunity.com/DevCenter/PythonEggs Python eggs] that really makes plugin development fun. This tutorial shows how to make an egg, successfully load an egg in Trac and in advanced topics how to serve templates and static content from an egg. You should be familiar with [trac:TracDev/ComponentArchitecture component architecture] and [trac:TracDev/PluginDevelopment plugin development]. This plugin is based on example in the plugin development article. Here we extend it a bit further. == Required items == First you need ''setuptools''. For instructions and files see [http://peak.telecommunity.com/DevCenter/EasyInstall#installing-easy-install EasyInstall] page. You also need Trac 0.9. Download it from the [trac:TracDownload#LatestDevelopmentRelease0.9beta2 TracDownload] page. == Directories == To develop a plugin you need to create few directories to keep things together. So let's create following directories: {{{ ./helloworld-plugin/ ./helloworld-plugin/helloworld/ ./helloworld-plugin/TracHelloworld.egg-info/ }}} == Main plugin == The first step is to generate the main module for this plugin. We will construct a simple plugin that will display "Hello world!" on the screen when accessed through /helloworld URL. The plugin also provides a "Hello" button that is, by default, rendered on the far right in the main navigation bar. So create ''helloworld.py'' in ''./helloworld-plugin/helloworld/'': {{{ #!python # Helloworld plugin from trac.core import * from trac.web.chrome import INavigationContributor from trac.web.main import IRequestHandler from trac.util import escape class UserbaseModule(Component): implements(INavigationContributor, IRequestHandler) # INavigationContributor methods def get_active_navigation_item(self, req): return 'helloworld' def get_navigation_items(self, req): yield 'mainnav', 'helloworld', 'Hello' \ % escape(self.env.href.helloworld()) # IRequestHandler methods def match_request(self, req): return req.path_info == '/helloworld' def process_request(self, req): req.send_response(200) req.send_header('Content-Type', 'text/plain') req.end_headers() req.write('Hello world!') }}} == Make it a module == To make the plugin a module, you simply create that magic ''_''____''_init_''____''_.py'' in ''./helloworld-plugin/helloworld/'': {{{ #!python # Helloworld module from helloworld import * }}} == Make it an egg == Now it's time to make it an egg. For that we need a chicken called ''setup.py'' in ''./helloworld-plugin/'': {{{ #!python from setuptools import setup PACKAGE = 'TracHelloworld' VERSION = '0.1' setup(name=PACKAGE, version=VERSION, packages=['helloworld']) }}} To make the egg loadable in Trac we need to create one more file. In ''./helloworld-plugin/!TracHelloworld.egg-info/'' create the file ''trac_plugin.txt'': {{{ helloworld }}} == First deployment == Now try to build the plugin. Run the command {{{python setup.py bdist_egg}}} in the directory where you created it. If everthing went OK you should have a .egg file in ''./dist'' directory. Copy this ''.egg'' file to ''/[your trac env]/plugins'' directory. If you're using mod_python you have to restart Apache. Now you should see ''Hello'' link at far right in main navigation bar when accessing your site. Click it. == Aftermath == Now you have successfully created your first egg. You can continue by reading [wiki:EggCookingTutorial/AdvancedEggCooking EggCookingTutorial/AdvancedEggCooking] to learn how to use Trac in your plugins.