Please allow inclusion of jinja2 extensions.

[wwarriner]

Hi there, enjoying use of the plugin. I anticipate this plugin will be a key part in making our documentation more concise and friendly.

I find myself frustrated by Jinja's ongoing challenges with consistent include indentation (#178). So, from the linked issue, I installed and began using this extension: https://github.com/stereobutter/jinja2_workarounds. The extension made it possible to have markdown-consistent indentation of template structure in the containing file.

To include the extension in the mkdocs-macros plugin I added the following to mkdocs.yml.

plugins:
  - macros:
      ...
      j2_extensions:
        - jinja2_workarounds.MultiLineInclude

This works exactly as expected, except that mkdocs now emits a warning on build because the option is "Unrecognised". We rely on the --strict flag to catch common issues from contributors, and don't want to turn it off, so we can't currently use the Jinja indentation extension in our documentation.

WARNING -  Config value 'plugins': Plugin 'macros' option 'j2_extensions': Unrecognised configuration name: j2_extensions

I see at line 119 in plugin.py the mkdocs-macros config schema is defined. Can the entry (j2_extensions, J2_STRING) please be added to the schema to allow users of your plugin to make use of Jinja extensions?

Thank you for your consideration, and for the awesome plugin!

[github-actions]

Welcome to this project and thank you!

[wwarriner]

Apologies, I realize it's not a J2_STRING, it's a list of strings. It isn't clear how that would be implemented, I'll investigate.

[wwarriner]

I've made PR #273 which I believe are the changes necessary for what I'd like to see. I'm out of time today, I'll verify this resolves my issue tomorrow and report back.

Actually I had more time than I thought and it does work locally installing the extension from my fork.

[fralau]

@wwarriner Thanks! Good job!

[fralau]

I will have to update the documentation to include this.

Jinja2 extensions are documented here: https://jinja.palletsprojects.com/en/stable/extensions/

Note: the reason why it works, is because the code was designed cleverly, to register all extensions that start with j2 into the jinja2 environment.

mkdocs-macros-plugin/mkdocs_macros/plugin.py

Lines 833 to 843 in 51a3afc

	# read the config variables for jinja2:
	for key, value in self.config.items():
	# take definitions in config_scheme where key starts with 'j2_'
	# (if value is not empty)
	# and forward them to jinja2
	# this is used for the markers
	if key.startswith('j2_') and value:
	variable_name = key.split('_', 1)[1] # remove prefix
	trace("Found j2 variable '%s': '%s'" %
	(variable_name, value))
	env_config[variable_name] = value

[wwarriner]

Thank you for all your hard work, very much appreciated!