[[PageOutline(2-5,Contents,pullout)]]

= Allows a component to state dependencies on other plugins

== Description

This plugin allows a Trac [trac:TracDev/ComponentArchitecture component] to state a dependency on another `Component`, via the `IRequireComponents` interface from `componentdependencies.interface`:

{{{#!python
class IRequireComponents(Interface):
    def requires():
        """list of component classes that this component depends on"""
}}}

The `Component` classes that are returned by the `requires` method will be enabled upon environment upgrade. This allows very simple dependencies. Of course, for installation, the required components are still required to be part of Python, as given in `install_requires` in `setup.py`.

This plugin will not work if required plugins are not present or loaded.

The files in [source:componentdependencyplugin/0.11/componentdependencies/test.py test.py] illustrate how to use the plugin. In your `trac.ini` file, enable the following plugins:
 * `ComponentDependencyPlugin`: 
  {{{#!ini
componentdependencies.componentdependency.componentdependencyplugin = enabled
}}}
 * `TestDependencyPlugin`:
  {{{#!ini
componentdependencies.test.testdependencyplugin = enabled
}}}

Trac will then require an upgrade. The `FooBarTest` component will be enabled in the upgrade.

== Bugs/Feature Requests

Existing bugs and feature requests for ComponentDependencyPlugin are 
[report:9?COMPONENT=ComponentDependencyPlugin here].

If you have any issues, create a 
[/newticket?component=ComponentDependencyPlugin new ticket].

[[TicketQuery(component=ComponentDependencyPlugin&group=type,format=progress)]]

== Download

Download the zipped source from [export:componentdependencyplugin here].

== Source

You can check out ComponentDependencyPlugin from [/svn/componentdependencyplugin/0.11 here] using Subversion, or [source:componentdependencyplugin browse the source] with Trac.

== Installation

General instructions on installing Trac plugins can be found on the [TracPlugins#InstallingaTracplugin TracPlugins] page.

== Recent Changes

[[ChangeLog(componentdependencyplugin, 3)]]

== Author/Contributors

''Originally developed at [http://openplans.org The Open Planning Project]''

'''Author:''' [wiki:k0s] [[BR]]
'''Maintainer:''' [[Maintainer]] [[BR]]
'''Contributors:'''