plone.autoinclude

Auto include code and zcml


Keywords
Python, Plone, CMS
License
CNRI-Python-GPL-Compatible
Install
pip install plone.autoinclude==1.0.1

Documentation

Coveralls License

plone.autoinclude

Automatically include zcml of a package when it is loaded in a Plone site.

Features

  • It is an alternative to z3c.autoinclude.
  • When a package registers an autoinclude entry point, we load its Python code at Zope/Plone startup.
  • And we load its zcml.
  • Works with Buildout-installed packages.
  • Works with pip-installed packages.

Compatibility

This is made for Python 3.6+. Since Plone 6.0.0a2 it is included in core Plone. See PLIP 3339.

It also works on Plone 5.2.

For add-on authors

When you have an existing package that has some zcml, you probably already have something like this in your setup.py:

entry_points="""
[z3c.autoinclude.plugin]
target = plone
"""

or in a dictionary:

entry_points={
    "z3c.autoinclude.plugin": [
        "target = plone",
    ],
}

or in setup.cfg:

[options.entry_points]
z3c.autoinclude.plugin =
    target=plone

This still works! You do not need to change anything.

But if you do not care about compatibility with z3c.autoinclude, you could use this new entry point:

entry_points="""
[plone.autoinclude.plugin]
target = plone
"""

It does the same thing, but it only works with plone.autoinclude.

Note: you should not add plone.autoinclude in your install_dependencies. It is the responsibility of the framework (usually Plone) to do this.

Entry point details

This is an entry point with all options specified:

entry_points="""
[plone.autoinclude.plugin]
target = plone
module = example.alternative
"""

You must specify at least one option, otherwise the entry point does not exist.

target
In which framework should your zcml be loaded? For a Plone add-on you would use plone. If Zope ever wants to use something similar, it could add configuration to look for packages with target="zope". You can come up with targets yourself, and load them in a policy package, maybe: cms, frontend, companyname, customername, nl/de (language). If target is empty, or the option is not there, the zcml will get loaded by all frameworks.
module
Use this when your package name is different from what you import in Python. See also the next section.

Different project and module name

Usually the project name of an add-on (what is in setup.py or setup.cfg) is the same as how you would import it in Python code. It could be different though. In that case, you may get a ModuleNotFoundError on startup: plone.autoinclude tries to import the project name and this fails.

The easiest way to solve this, is to switch from z3c.autoinclude.plugin to plone.autoinclude.plugin, if you have not done so already, and specify the module. In setup.py:

setup(
    name="example.different2",
    entry_points="""
    [plone.autoinclude.plugin]
    module = example.somethingelse2
    """,
)

If you must still support Plone 5.2 and are tied to z3c.autoinclude.plugin, or if you cannot edit the problematic package, you can work around it. You set an environment variable AUTOINCLUDE_ALLOW_MODULE_NOT_FOUND_ERROR. To accept ModuleNotFoundError in all packages:

export AUTOINCLUDE_ALLOW_MODULE_NOT_FOUND_ERROR=1

To accept ModuleNotFoundError only in specific packages, use a comma-separated list of project names, with or without spaces:

export AUTOINCLUDE_ALLOW_MODULE_NOT_FOUND_ERROR=example.different,example.different2

In the logs you will see a traceback so you can investigate, but startup continues. You should make sure the zcml of this package is loaded in some other way.

Comparison with z3c.autoinclude

  • z3c.autoinclude supports includeDependencies in a zcml file in your package. This would look in the setup_requires of the package to find dependencies. For each, it would load the zcml. This can take quite long. It might not work for packages installed by pip, but this is not confirmed. In the Plone community this is discouraged, and Plone already disables this in the tests. plone.autoinclude does not support this. You should load the zcml of the dependencies explicitly in the configure.zcml of your package.
  • z3c.autoinclude tries hard to find packages in non-standard places, installed in weird or old ways, or with a module name that differs from the package name, with code especially suited for eggs that buildout installs. plone.autoinclude simply uses importlib.import_module on the module name. If there is a mismatch between package name and module name, you can set module = modulename in your entry point.
  • z3c.autoinclude does not support empty targets. The target of the entry point must match the target that is being loaded. plone.autoinclude does support empty targets: they will always get loaded. This is not good or bad, it is just a different choice.
  • z3c.autoinclude supports disabling loading the plugins, via either an environment variable or an api call. plone.autoinclude does not. But Products.CMFPlone currently loads the z3c.autoinclude plugins unless a zcml condition is true: not-have disable-autoinclude. When Products.CMFPlone switches to plone.autoinclude, it can use this same condition.

In general, plone.autoinclude is a bit more modern, as it only started in 2020, and only supports Python 3.

Usage in Plone 5.2

Since Plone 6.0.0a2 this is included in core, so nothing needs to be done there. If you want to use it in Plone 5.2, this is possible. First add it to your buildout:

[instance]
...
eggs +=
    plone.autoinclude
zcml +=
    plone.autoinclude.ploneinclude-meta
    plone.autoinclude.ploneinclude
    plone.autoinclude.ploneinclude-overrides

This will include three zcml files from the ploneinclude directory. It will do this:

  • Disable the original z3c.autoinclude.
  • Load CMFPlone meta.zcml, so the order in which zcml is loaded stays mostly the same.
  • Load plone.autoinclude meta.zcml.
  • Automatically include the meta.zcml of all plone plugins.
  • Load CMFPlone configure.zcml.
  • Automatically include the configure.zcml of all plone plugins.
  • Load CMFPlone overrides.zcml.
  • Automatically include the overrides.zcml of all plone plugins.

For other frameworks

You can take the above section as example, and take care of the following

  • Include the plone.autoinclude package in install_requires.
  • In your meta.zcml load the meta.zcml of plone.autoinclude.
  • In your meta.zcml load the meta.zcml of your plugins: <autoIncludePlugins target="your-framework" file="meta.zcml" />
  • In your configure.zcml load the configure.zcml of your plugins: <autoIncludePlugins target="your-framework" file="configure.zcml" />
  • In your overrides.zcml load the meta.zcml of your plugins in override mode: <autoIncludePluginsOverrides target="your-framework" file="meta.zcml" />

Installation with pip

Let's leave buildout completely out of the picture and only use pip, in this case with plone 5.2.5. We use the legacy resolver from pip, to avoid some possible problems that have nothing to do with autoinclude:

# Create virtual environment in the current directory:
python3.8 -mvenv .
# Install Plone and Paste:
bin/pip install -c https://dist.plone.org/release/5.2.5/constraints.txt Products.CMFPlone Paste --use-deprecated legacy-resolver
# Install plone.autoinclude from the current git checkout:
bin/pip install -e .
# or 'bin/pip install plone.autoinclude' to get the latest from PyPI.
# Create the Zope WSGI instance:
bin/mkwsgiinstance -d . -u admin:admin
# Copy our zcml that disables z3c.autoinclude and enables our own.
cp -a package-includes etc/
# Start Zope:
bin/runwsgi -v etc/zope.ini

Contribute or get support

License

The project is licensed under the GPLv2.