Here's the proof of concept FunctionLoader that showed me that this wasn't going to work: ```diff diff --git a/datasette/app.py b/datasette/app.py index 4b28e71..b076be7 100644 --- a/datasette/app.py +++ b/datasette/app.py @@ -21,7 +21,7 @@ from pathlib import Path from markupsafe import Markup from itsdangerous import URLSafeSerializer import jinja2 -from jinja2 import ChoiceLoader, Environment, FileSystemLoader, PrefixLoader +from jinja2 import ChoiceLoader, Environment, FileSystemLoader, FunctionLoader, PrefixLoader from jinja2.environment import Template from jinja2.exceptions import TemplateNotFound import uvicorn @@ -300,6 +300,7 @@ class Datasette: template_paths.append(default_templates) template_loader = ChoiceLoader( [ + FunctionLoader(self._load_template_from_plugins), FileSystemLoader(template_paths), # Support {% extends "default:table.html" %}: PrefixLoader( @@ -322,6 +323,17 @@ class Datasette: self._root_token = secrets.token_hex(32) self.client = DatasetteClient(self)

• def _load_template_from_plugins(self, template):

• "If auto reloading is enabled it’s called to check if the template changed"

• uptodatefunc = lambda: True
• source = pm.hook.load_template(
• template=template,
• datasette=self,
• )
• if source is None:
• return None
• return source, template, uptodatefunc + @property def urls(self): return Urls(self) @@ -719,35 +731,7 @@ class Datasette: else: if isinstance(templates, str): templates = [templates] -

• Give plugins first chance at loading the template

• break_outer = False
• plugin_template_source = None
• plugin_template_name = None
• template_name = None
• for template_name in templates:
• if break_outer:
• break
• plugin_template_source = pm.hook.load_template(
• template=template_name,
• request=request,
• datasette=self,
• )
• plugin_template_source = await await_me_maybe(plugin_template_source)
• if plugin_template_source:
• break_outer = True
• plugin_template_name = template_name
• break
• if plugin_template_source is not None:
• template = self.jinja_env.from_string(plugin_template_source)
• else:
• template = self.jinja_env.select_template(templates)
• for template_name in templates:
• from_plugin = template_name == plugin_template_name
• used = from_plugin or template_name == template.name
• templates_considered.append(
• {"name": template_name, "used": used, "from_plugin": from_plugin}
• )
• template = self.jinja_env.select_template(templates) body_scripts = [] # pylint: disable=no-member for extra_script in pm.hook.extra_body_script( diff --git a/datasette/hookspecs.py b/datasette/hookspecs.py index ca84b35..7804def 100644 --- a/datasette/hookspecs.py +++ b/datasette/hookspecs.py @@ -50,7 +50,7 @@ def extra_template_vars(

@hookspec(firstresult=True) -def load_template(template, request, datasette): +def load_template(template, datasette): "Load the specified template, returning the template code as a string"

diff --git a/docs/plugin_hooks.rst b/docs/plugin_hooks.rst index 3c57b6a..8f2704e 100644 --- a/docs/plugin_hooks.rst +++ b/docs/plugin_hooks.rst @@ -273,15 +273,12 @@ Example: `datasette-cluster-map <https://github.com/simonw/datasette-cluster-map

.. _plugin_hook_load_template:

-load_template(template, request, datasette)

+load_template(template, datasette) +----------------------------------

template - string The template that is being rendered, e.g. database.html

-request - object or None - The current HTTP :ref:internals_request. This can be None if the request object is not available. - datasette - :ref:internals_datasette You can use this to access plugin configuration options via datasette.plugin_config(your_plugin_name) ```