Remove load_plugin hook - closes #1073

Refs #1042

This reverts commit 81dea4b07a.

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, PrefixLoader, escape
 from jinja2.environment import Template
 from jinja2.exceptions import TemplateNotFound
 import uvicorn
@@ -713,41 +713,12 @@ class Datasette:
         self, templates, context=None, request=None, view_name=None
     ):
         context = context or {}
-        templates_considered = []
         if isinstance(templates, Template):
             template = templates
         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(
@@ -812,7 +783,6 @@ class Datasette:
                 ),
                 "base_url": self.config("base_url"),
                 "csrftoken": request.scope["csrftoken"] if request else lambda: "",
-                "templates_considered": templates_considered,
             },
             **extra_template_vars,
         }

datasette/hookspecs.py

@@ -49,11 +49,6 @@ def extra_template_vars(
     "Extra template variables to be made available to the template - can return dict or callable or awaitable"
 
 
-@hookspec(firstresult=True)
-def load_template(template, request, datasette):
-    "Load the specified template, returning the template code as a string"
-
-
 @hookspec
 def publish_subcommand(publish):
     "Subcommands for 'datasette publish'"

datasette/templates/base.html

@@ -79,10 +79,6 @@ document.body.addEventListener('click', (ev) => {
     <script>{{ body_script }}</script>
 {% endfor %}
 
-{% if templates_considered %}
-<!-- Templates considered:
-{% for template in templates_considered %}- {{ template.name }}{% if template.used %} (used{% if template.from_plugin %}, from plugin{% endif %}){% endif %}
-{% endfor %}-->
-{% endif %}
+{% if select_templates %}<!-- Templates considered: {{ select_templates|join(", ") }} -->{% endif %}
 </body>
 </html>

datasette/views/base.py

@@ -119,15 +119,22 @@ class BaseView:
 
     async def render(self, templates, request, context=None):
         context = context or {}
+        template = self.ds.jinja_env.select_template(templates)
         template_context = {
             **context,
             **{
                 "database_color": self.database_color,
+                "select_templates": [
+                    "{}{}".format(
+                        "*" if template_name == template.name else "", template_name
+                    )
+                    for template_name in templates
+                ],
             },
         }
         return Response.html(
             await self.ds.render_template(
-                templates, template_context, request=request, view_name=self.name
+                template, template_context, request=request, view_name=self.name
             )
         )
 

docs/plugin_hooks.rst

@@ -271,24 +271,6 @@ You can also return an awaitable function that returns a string.
 
 Example: `datasette-cluster-map <https://github.com/simonw/datasette-cluster-map>`_
 
-.. _plugin_hook_load_template:
-
-load_template(template, request, 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)``
-
-Load the source code for a template from a custom location. Hooks should return a string, or ``None`` if the template is not found.
-
-Datasette will fall back to serving templates from files on disk if the requested template cannot be loaded by any plugins.
-
 .. _plugin_hook_publish_subcommand:
 
 publish_subcommand(publish)

tests/fixtures.py

@@ -43,7 +43,6 @@ EXPECTED_PLUGINS = [
             "extra_js_urls",
             "extra_template_vars",
             "forbidden",
-            "load_template",
             "menu_links",
             "permission_allowed",
             "prepare_connection",

tests/plugins/my_plugin.py

@@ -308,9 +308,3 @@ def table_actions(datasette, database, table, actor):
             },
             {"href": datasette.urls.instance(), "label": "Table: {}".format(table)},
         ]
-
-
-@hookimpl
-def load_template(template, request):
-    if template == "show_json.html" and request.args.get("_special"):
-        return "<h1>Special show_json: {{ filename }}</h1>"

tests/test_plugins.py

@@ -801,8 +801,3 @@ def test_hook_table_actions(app_client):
         {"label": "Database: fixtures", "href": "/"},
         {"label": "Table: facetable", "href": "/"},
     ]
-
-
-def test_hook_load_template(app_client):
-    response = app_client.get("/-/databases?_special=1")
-    assert response.text == "<h1>Special show_json: databases.json</h1>"