This package adds two new ZCML directives to automatically detect ZCML files to include: "includeDependencies" and "includePlugins".
When you want to include a Zope-based package in your application, you have to repeat yourself in two places: you have to add the package itself (in a setup.py, buildout, etc) and you also have to include its ZCML with an <include> directive or a package-includes slug. Because you have to repeat yourself, you can easily make an error where you add a new package but forget to include its ZCML.
z3c.autoinclude lets you circumvent this error-prone process with automatic detection and inclusion of ZCML files.
The "includeDependencies" directive searches through the dependencies in your setup.py file (install_requires), and includes the ZCML files in those packages that it finds. Inclusion order matches the order in the setup.py file. You can pass a path for the package you want to include dependencies for, but typically you pass in the current package, as follows:
<includeDependencies package="." />
With this directive, you no longer have to add an explicit
package=new.dependency> for every new dependency of your project.
Grok and grokproject use this functionality out of the box. The
grokproject command will automatically add the
directive in the ZCML of the project it generates. You can then stop
worrying about manual ZCML inclusion in the vast majority of cases.
The "includePlugins" directive uses entry points to find installed packages that broadcast themselves as plugins to a particular base package. You can pass a path for the package you want to include plugins for, but typically you pass in the current package, as follows:
<includePlugins package="." />
To broadcast a package as a plugin to a base package called "my_base",
add the following lines to the plugin package's
entry_points=""" [z3c.autoinclude.plugin] target = my_base """
To make the z3c.autoinclude directives available for use in your
application or framework, you need to include it (in your
meta.zcml for instance), like this:
<include package="z3c.autoinclude" file="meta.zcml" />
Grok already does this for you automatically.
It is often useful to disable z3c.autoinclude's functionality for debugging purposes or test runs. To disable autoinclusion, set the environment variables "Z3C_AUTOINCLUDE_DEPENDENCIES_DISABLED" and "Z3C_AUTOINCLUDE_PLUGINS_DISABLED".
When autoinclusion is disabled, the autoinclusion directives will issue a warning to the log and do nothing.
The includeDependencies directive automatically includes
meta.zcml files that live in the main
package directories. For automatic inclusion of dependencies'
overrides, there is an <includeDependenciesOverrides> directive.
In some cases, a package may use unusual names or
locations for its ZCML files. In that case you will need to modify
meta.zcml yourself to
include the ZCML using the manual
The includePlugins directive automatically includes
meta.zcml files by default, and the includePluginsOverrides
directive automatically includes
overrides.zcml files by default.
But, like "<include>", these directives also have an optional "file"
parameter, so you can automatically include all
foo.zcml files in
your package's plugins like this:
<includePlugins package="." file="foo.zcml" />
The includeDependencies directives will soon offer this option as well.